Comparisons of Electron Transfer Reactions in a Cyanobacterial Tetrameric and Trimeric Photosystem I Complexes

Abstract

Photosystem I (PSI) is a Type-I reaction center and the largest photosynthetic complex to be characterized. In cyanobacteria, PSI is organized as a trimer with a three-fold axis of symmetry. Recently, a tetrameric form of PSI has been identified in cyanobacteria. Plastids in plants and algae only contain monomeric PSI, suggesting that tetrameric PSI may be key in the transition from ancestral cyanobacterial trimeric PSI to plant/algal monomeric PSI. We have investigated the kinetics of e^- transfer to the initial acceptor in PSI tetramer isolated from Chroococcidiopsis TS-821. Using a pump-probe technique with 25-fs low-energy, 720 nm pump pulses, we measure the ultrafast (<100 fs) conversion of a delocalized exciton into a charge-separated state between the primary donor P₇₀₀ and the primary acceptor A₀. Comparison with previous pump-probe analysis of the trimeric PSI complexes from Synechocystis sp PCC 6803 (1), reveal that the tetrameric (PSI) complexes from Chroococcidiopsis sp TS-821 is quite similar. The transfer of an electron from the A₀ to the following acceptor A1 (phylloquinone) takes place in a time frame of about 30 ps, which is slightly longer compared to PSI trimeric complex (~24 ps). The slight spectral differences between trimeric and tetrameric PSI complexes is discussed.

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The Solar Ultraviolet Environment at the Ocean

Abstract

Atmospheric and oceanic radiative transfer models were used to compute spectral radiances between 285 and 400 nm onto horizontal and vertical plane surfaces over water. The calculations kept track of the contributions by the sun's direct beam, by diffuse sky radiance, by radiance reflected from the sea surface, and by water-leaving radiance. Clear, hazy, and cloudy sky conditions were simulated for a range of sun zenith angles, wind speeds, and atmospheric ozone concentrations. The radiances were used to estimate erythemal exposures due to the sun and sky, as well as from radiation reflected by the sea surface and backscattered from the water column. Diffuse-sky irradiance is usually greater than direct-sun irradiance at wavelengths below 330 nm, and reflected and water-leaving irradiance accounts for less than 20% of the UV exposure on a vertical surface. Total exposure depends strongly on solar zenith angle and azimuth angle relative to the sun. Sea surface roughness affects the UV exposures by only a few percent. For very clear waters and the sun high in the sky, the UV index within the water can be greater than 10 at depths down to two meters, and greater than 6 down to 5 m.

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Tumour necrosis factor-α-inhibitor-induced neutrophilic folliculitis presenting with strong lesional expression of interleukin-36γ

Depression- and anxiety-like behaviour is related to BDNF/TrkB signalling in a mouse model of psoriasis

Summary

Background

The prevalence of anxiety and depression is significantly higher in individuals with psoriasis than in the general population. Clinical data also show that anti-anxiety and antidepression drugs can reduce skin lesions in patients with psoriasis, but the actual mechanism is still poorly understood.

Aim

To investigate whether brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrKB) signalling plays a role in the mechanism underlying psoriasis with depression and anxiety behaviours.

Methods

Expression of BDNF and tropomyosin receptor kinase B (TrKB) in the K5.Stat3C mouse, an animal model of psoriasis, were investigated by reverse transcription PCR and Western blotting. Anxiety-like behaviours in the elevated-plus maze test and changes in BDNF/TrkB that have been implicated in depression and anxiety behaviours were measured. Skin lesions induced by 12-O-tetradecanoyl phorbol-13-acetate (TPA) were also measured when the mice were administered fluoxetine and K252a, an antagonist of TrkB.

Results

The antidepression and anti-anxiety drug fluoxetine reduced TPA-induced skin lesions and increased expression of BDNF and TrkB in K5.Stat3C mice. More importantly, the effects of fluoxetine were reversed by the TrkB antagonist K252a.

Conclusions

BDNF/TrkB signalling participates in the pathological mechanism of depression and anxiety behaviours in psoriasis. Our findings provide a new therapeutic strategy for the treatment of skin lesions in psoriasis.

Tripartite equilibrium strategy for a carbon tax setting problem in air passenger transport

Abstract

Carbon emissions in air passenger transport have become increasing serious with the rapidly development of aviation industry. Combined with a tripartite equilibrium strategy, this paper proposes a multi-level multi-objective model for an air passenger transport carbon tax setting problem (CTSP) among an international organization, an airline and passengers with the fuzzy uncertainty. The proposed model is simplified to an equivalent crisp model by a weighted sum procedure and a Karush-Kuhn-Tucker (KKT) transformation method. To solve the equivalent crisp model, a fuzzy logic controlled genetic algorithm with entropy-Bolitzmann selection (FLC-GA with EBS) is designed as an integrated solution method. Then, a numerical example is provided to demonstrate the practicality and efficiency of the optimization method. Results show that the cap tax mechanism is an important part of air passenger trans'port carbon emission mitigation and thus, it should be effectively applied to air passenger transport. These results also indicate that the proposed method can provide efficient ways of mitigating carbon emissions for air passenger transport, and therefore assist decision makers in formulating relevant strategies under multiple scenarios.

Driving chronicity in rheumatoid arthritis - perpetuating role of myeloid cells

Abstract

Acute inflammation is a complex and tightly regulated homeostatic process that includes leukocyte migration from the vasculature into tissues to eliminate the pathogen/injury, followed by a pro-resolving response promoting tissue repair. However, if inflammation is uncontrolled as in chronic diseases such as Rheumatoid Arthritis (RA) it leads to tissue damage and disability. Synovial tissue inflammation in RA patients is maintained by sustained activation of multiple inflammatory positive-feedback regulatory pathways in a variety of cells including myeloid cells. In this review, we will highlight recent evidence uncovering biological mechanisms contributing to the aberrant activation of myeloid cells that contributes to perpetuation of inflammation in RA, and discuss emerging data on anti-inflammatory mediators contributing to sustained remission that may inform a novel category of therapeutic targets. This article is protected by copyright. All rights reserved.

APOBEC mutagenesis in drug resistance and immune escape in HIV and cancer evolution

Abstract

The APOBEC mutational signature has only recently been detected in a multitude of cancers through next-generation sequencing. In contrast, APOBEC has been a focus of virology research for over a decade. Many lessons learnt regarding APOBEC within virology are likely to be applicable to cancer. In this review, we explore the parallels between the role of APOBEC enzymes in HIV and cancer evolution. We discuss data supporting the role of APOBEC mutagenesis in creating HIV genome heterogeneity, drug resistance, and immune escape variants. We hypothesize similar functions of APOBEC will also hold true in cancer.

PD-1 blockade with nivolumab in endemic Kaposi sarcoma

Outcome in colorectal cancer – tumour, stroma and so much more

colorectal cancerprognosisinflammationtumour microenvironment

Short course of cyclosporin A as a treatment option for drug-induced hypersensitivity syndrome: Case reports and review of the published work

Clinical and immunohistochemical comparative study of the efficacy of carboxytherapy vs platelet-rich plasma in treatment of stretch marks

Summary

Background

Striae distensae are dermal scars with a linear atrophic depression. The exact origin of striae distensae remains unrevealed, but low expression of collagen and fibronectin genes in the affected tissue was found. Several treatment modalities have been proposed, yet no consistent modality is available.

Aim of the work

To evaluate and compare the efficacy and safety of carboxytherapy vs platelet-rich plasma (PRP) in treatment of stretch marks.

Patients and methods

This study included 20 patients with striae alba. Every patient received treatment in the form of PRP injection in their right side (group A) and carboxytherapy session in their left side (group B) every 3-4 weeks for 4 sessions. Skin biopsies were taken before and after treatment, and they were subjected to fibronectin immunohistochemical stain.

Results

There was a significant improvement in striae alba in both groups after than before treatment. There was no significant difference between both groups as regards either percentage of improvement, response (grading scale), or patient satisfaction. The fibronectin-stained area was significantly higher in both groups after than before treatment, and it was significantly higher after treatment in group (B) than group (A).

Conclusions

Both methods were safe and effective with minimal side effects. There was no significant difference between both methods of treatments. This was confirmed histopathologically by fibronectin expression which is found to be low in striae and increased significantly after treatment. But fibronectin expression was higher in group (B) than (A).

Filler migration and extensive lesions after lip augmentation: Adverse effects of polydimethylsiloxane filler

Summary

Polydimethylsiloxane (PDMS), also called liquid silicone, belongs to a group of polymeric compounds that are commonly referred to as silicones. These filling agents have been used as injectable filler for soft tissue augmentation. There are limited experiences about management of the severe complications related to filler migration associated with PDMS injection. We present a 35-year-old female with severe erythema, edema over her cheeks and neck, and multiple irregularities following cosmetic lip augmentation with PDMS. Further studies are required for management of this complicated case of PDMS injection.

Protective effect of conditioner agents on hair treated with oxidative hair dye

Summary

Background

Hair coloring is broadly used by women and men either to change their natural hair color or to delay the onset of gray hair. Oxidative dyes may damage the hair, as chemical and physical processes are required to convert the fiber structure and, consequently, alterations in its mechanical and surface properties.

Objectives

The aim of this study was to evaluate the protective effect of silanetriol (and) Panthenol, PEG-12 dimethicone, and hydrolyzed silk (and) hydrolyzed milk protein (and) lactose as conditioner agents on hair treated with oxidative hair dye by protein loss, combability, and breaking strength.

Methods

In this research, we analyzed the untreated hair (sample I) and the effect of oxidative hair dye emulsions, with or without conditioner agents (sample II) silanetriol (and) Panthenol (sample III), PEG-12 dimethicone (sample IV), and hydrolyzed silk (and) hydrolyzed milk protein (and) lactose (sample V) on Caucasian hair. The hair samples were submitted to protein loss quantification, breaking strength, and combing analysis.

Results

For protein loss, the results were: II^a = V^a > IV^b > III^c > I^d. For the breaking strength: I^e = II^e = III^e = IV^e = V^e. For the combing analysis for wet and dry hair, the results were, respectively: II^a > III^b = IV^b > V^c > I^d and II^A > III^b = V^b > IV ^c= I^c. Data classified by different letters presented statistically significant alterations, α = 5, P ≤ . 05, n = 15.

Conclusions

Based on these results, the incorporation of conditioner agents into emulsion blond color decreased the damage caused by the coloring process.

Origin and effect factors of sedimentary organic carbon in a karst groundwater-fed reservoir, South China

Abstract

Reservoirs are commonly recharged by groundwater that is rich in bicarbonate ions in karst regions of South China, and the recharge of this groundwater to the reservoir can affect the biogeochemical processes of carbon sedimentation at the reservoir bottom. In this study, Dalongdong Reservoir, which is mainly recharged by two subterranean streams, was investigated based on a 42-cm-thick sedimentary core and the ²¹⁰Pb/¹³⁷Cs dating technique and isotope analyses to understand the sedimentary history and identify the carbon sources. The ²¹⁰Pb/¹³⁷Cs age model showed that the sediments were accumulated over the last 60 years. The annual increase precipitation and temperature showed no obvious change compared with trends of δ¹³C in total organic carbon (δ¹³C_org), δ¹⁵N values in total nitrogen, and the carbon and nitrogen ratio (C/N). This shows that climate was not the main control of the variation in sediment factors. Based on δ¹³C_org, δ¹⁵N, C/N, and isotopic mixing modeling, sources of organic carbon in the sediments were derived from plankton (60.84%), soil (22.93%), waste water (14.56%), and terrestrial plants (1.67%). From 1958 to 1978, reservoir establishment and leakage affected the contribution of the four sources. The contribution of the plankton source increased from 1978 to 2015, resulting from change of water level and continued input of external nitrogen. However, because of the revegetation supplied by an economic aid project the contribution of soil showed a considerable decreasing trend from 1978 to 2002. After 2002, For "Grain for Green" project, the contribution from soil further decreased. After reservoir construction, the contribution of waste water stabilized. The contribution of terrestrial plants started increased rapidly after 2002. Karst groundwater, which contains more dissolved inorganic carbon containing lower δ¹³C_DIC than the water sources of other lakes or reservoirs, makes the δ¹³C_org value of sediment more negative by phytoplankton photosynthesis in the reservoir.

Emotion and Judgment: Two Sources of Moral Motivation in Mèngzǐ

Abstract

David Nivison has argued that Mèngzǐ 孟子 postulates only one source of moral motivation (namely "heart" as the locus of moral emotions or feelings), whereas Mèngzǐ's rival thinkers such as Gàozǐ 告子 or the Mohist Yí Zhī 夷之 additionally postulate "maxims" or "doctrines" that are produced by some sort of moral reasoning. In this essay I critically examine this interpretation of Nivison's, and alternatively argue that moral emotions in Mèngzǐ, basically understood as concern-based construals, are often an insufficient source of moral action, and an additional source of moral motivation, specifically a conviction or judgment of what is the right thing to do in a certain situation in question, is often necessary for one to complete a moral action. This implies that Mèngzǐ should be interpreted to postulate two sources of moral motivation just as his rival thinkers do, namely moral emotion on one hand and judgment and practical reasoning on the other.

From Sensations to Concepts: a Proposal for Two Learning Processes

Abstract

This article presents two learning processes in order to explain how children at an early age can transform a complex sensory input to concepts and categories. The first process constructs the perceptual structures that emerge in children's cognitive development by detecting invariants in the sensory input. The invariant structures involve a reduction in dimensionality of the sensory information. It is argued that this process generates the primary domains of space, objects and actions and that these domains can be represented as conceptual spaces. Once the primary domains have been established, the second process utilizes covariances between different dimensions of the domains in order to identify natural clusters of entities. The clusters are then are used to determine concepts as regions in the spaces. As an application, the processes are used to resolve the so-called 'complex first paradox' that emerges from the fact that children, in general, learn nouns earlier than adjectives, even though nouns are semantically more complex than adjectives.

Ecotoxicology and toxicology: problems and decisions

Lepra lepromatosa simulando lupus eritematoso sistémico

Publication date: January 2018
Source:Piel, Volume 33, Issue 1
Author(s): Camila Pérez-Madrid, Juan Camilo Beltrán Alzate, Natalia Vélez Lagoueyte, Verónica Alba Amarillo

Lesiones pruriginosas de meses de evolución en un paciente con antecedentes de micosis fungoide. Diagnóstico y comentario

Publication date: January 2018
Source:Piel, Volume 33, Issue 1
Author(s): Montserrat Molgó-Novell, Paula Majluf, Daniela Novoa, Sergio González Bombardiére

Placas eritematosas arciformes como manifestación de hipotiroidismo. Diagnóstico y comentario

Publication date: January 2018
Source:Piel, Volume 33, Issue 1
Author(s): Claudia Quiroz Palominos, Julio Parra Cares, Roberto Bustos Macaya

Alternative approaches to the therapeutic drug monitoring of prophylactic posaconazole in haematology patients

Publication date: Available online 7 January 2018
Source:Journal de Mycologie Médicale
Author(s): T.-A. Vyzantiadis, E. Yannaki, D.A. Oliver, A.-M. Markantonatou, Z. Boussiou, A. Louka, E. Zachrou, E.M. Johnson
ObjectiveThe intention of the study was to assess whether a unique daily specimen is adequate for prophylactic posaconazole TDM in haematology patients and if bioassay and HPLC produce similar results and could be equally used in clinical setting.MethodSerum specimens from thirty haematology patients were collected at the end of the first and second week of treatment, just before the morning dose, 2 and 6 to 8hours afterwards. Levels were measured by bioassay in 157 specimens and additionally by HPLC in 51 of them.ResultsBioassay levels were correlated inter and intra daily, with no statistical difference between them, irrespective of the timing. The same was true for HPLC measurements. There was no statistical difference between bioassay (median: 1.60mg/L, interquartile range: 0.60–2.30) and HPLC levels (median: 1.16mg/L, interquartile range: 0.56–1.72), while they were significantly correlated.ConclusionIn clinically stable haematology patients, a random specimen on any day after steady state serum concentrations have been achieved is probably adequate in order to monitor posaconazole levels. In the case of monotherapy, a bioassay is an acceptable alternative to HPLC.

An assessment of the use of antihistamines in the management of atopic dermatitis

Publication date: Available online 6 January 2018
Source:Journal of the American Academy of Dermatology
Author(s): Alice He, Steven R. Feldman, Alan B. Fleischer
BackgroundAntihistamines are often used to treat pruritus associated with atopic dermatitis (AD) despite lack of evidence for their efficacy. The American Academy of Dermatology does not recommend the general use of antihistamines in the management of AD, although the value of short-term sedating antihistamine use for insomnia secondary to itch is recognized.ObjectiveTo assess the use of sedating and non-sedating antihistamines for AD from 2003-2012.MethodsThe National Ambulatory Medical Care Survey (NAMCS) provided data on physician visits from 2003-2012. Sedating and non-sedating antihistamine use was identified at AD visits.ResultsThere were 990,000 annual visits for AD. Antihistamines were prescribed for AD in a significant proportion of visits across physician specialties (16-44%). Dermatologists and pediatricians primarily used sedating antihistamines (58-70%), while the majority of family/general practitioners, internists, and other specialists prescribed non-sedating antihistamines for AD (55-100%)LimitationsWe were limited by the accuracy of AD diagnosis and medication recording.ConclusionsAntihistamines are widely used for the treatment of AD. There is no high-level evidence to suggest that non-sedating antihistamines reduce itch in patients with AD, or that sedating antihistamines provide benefit in controlling AD symptoms (except perhaps sleep and AD co-morbidities, such as allergic rhinitis).

In vitro assessment of the broad-spectrum ultraviolet protection of clothing

Publication date: Available online 6 January 2018
Source:Journal of the American Academy of Dermatology
Author(s): Ellinor Q. Coyne, Michael K. Lichtman, Julie Simons, Ajoy K. Sarkar, Thomas M. Rünger

Personal History of Keratinocyte Carcinoma is Associated with Reduced Risk of Death from Invasive Melanoma in Men

Publication date: Available online 6 January 2018
Source:Journal of the American Academy of Dermatology
Author(s): Fengju Song, Steven T. Chen, Xin Li, Jiali Han
BackgroundPrevious studies have found an increased risk of invasive cutaneous melanoma (CM) among those with a history of keratinocyte carcinoma (KC).ObjectiveThe aim of this study is to evaluate the risk of CM death after KC.MethodsThe study was based on the Health Professionals Follow-up Study (HPFS). Cox proportional hazards model was used to examine the hazard ratio (HR) of CM death associated with personal history of KC, among the entire study population (primary analysis) and invasive CM cases (secondary analysis) respectively.ResultsWe documented a total of 908 invasive CM cases over a total of 0.7 million person-years of follow-up. Among all participants, the risk of developing either lethal or non-lethal invasive CM increased for those with KC history. The risk of melanoma death based on KC history was non-significantly increased, with HR (95% CI) of 1.53 (0.95 – 2.46). In the case-only analysis, those with KC history had a significantly lower risk of melanoma death compared with those with no such history, HR=0.60 (0.35-0.94).LimitationsBecause HPFS consists exclusively of male health professionals, the results of this study may not be extended to the entire population.ConclusionPersonal history of KC is associated with a decreased risk of melanoma-specific death among male patients with invasive CM.

Post-diagnosis aspirin use and overall survival in patients with melanoma

Publication date: Available online 6 January 2018
Source:Journal of the American Academy of Dermatology
Author(s): Saleh Rachidi, Kristin Wallace, Hong Li, Tim Lautenschlaeger, Zihai Li
BackgroundMouse studies show that tumor-derived prostaglandins and platelets promote melanoma progression and immune-evasion.ObjectiveDetermine if aspirin confers longer survival in patients with melanoma.MethsodsA retrospective cohort study of 1,522 patients at Indiana University Health (IUH) diagnosed with melanoma between 2000 and 2014 and followed up through September, 2016.ResultsAspirin use was associated with longer overall survival in univariate analysis and after controlling for age, sex, stage, and treatment modalities (HR 0.58, 95% CI [0.45-0.75]). Aspirin use was not associated with survival in patients with in situ and stage I melanoma, but was associated with better survival in stages II (HR 0.45, 95% CI [0.24-0.82]) and III (HR 0.57, 95% CI [0.34-0.96]). No statistical significance was observed in stage IV patients (HR 0.55, 95% CI [0.27-1.13]). In turn, patients using aspirin before diagnosis were less likely to be diagnosed in stages III or IV disease.LimitationsObservational study.ConclusionsAspirin could provide a survival advantage in melanoma. Clinical trials investigating the therapeutic potential of aspirin are warranted.

Just A Quick Pic: Ethics of Medical Photography

Publication date: Available online 6 January 2018
Source:Journal of the American Academy of Dermatology
Author(s): Tiana Kazemi, Kachiu C. Lee, Lionel Bercovitch

Issue Information

Pápulas violáceas sobre mácula acrómica

Publication date: Available online 6 January 2018
Source:Actas Dermo-Sifiliográficas
Author(s): A. Imbernón-Moya, F. Burgos, M.Á. Gallego-Valdés