First Principles Study of Nickel Complex with 1,3-dithiole-2-thione-4,5-dithiolate Ligands as Model Photosensitizers

Dye-sensitized solar cells (DSSCs) have become in one important and promising technology in the photovoltaic field. The ability for a sensitizer to harvest light photons and inject the excited electrons into a photoanode, typically a metal oxide, determines the performance and operation range of the solar cell. Metal complexes with 1,3-dithiole-2-thione-4,5-dithiolate (dmit) ligands, which are an important class of functional materials, have received extensive attention due to their intriguing chemical and physical properties. The electronic and molecular properties of isolated and adsorbed nickel complexes with dmit ligands have been investigated using first principles calculations based on the density functional theory (DFT). Adsorption energies of metal complexes supported on the anatase TiO2(101) surface were calculated for three different configurations, linked by sulphur atom of Sthione, Sthiole-Sthiolate, and planar. The most stable adsorption configurations found in this study are the Sthiole-Sthiolate and the planar forms for the nickel complex. TD-DFT molecular calculations reveal that the lowest energy transition in ultraviolet visible near-infrared (UV-Vis-NIR) mainly corresponds to the HOMO-LUMO π–π* excitation for the nickel complex. The effect of the TiO2(101) surface on the absorption spectra of the nickel complex is practically limited to a red shift of about 0.1-0.3 eV. The analysis of the density of states for the dmit/TiO2(101) system shows that the LUMO of the metal complex lies at the edge of the TiO2 conduction band indicating, therefore, that electron injection from the complex excited state into the semiconductor surface is unlikel

Chronic spontaneous urticaria: a survey of 852 cases of childhood-onset systemic Lupus Erythematosus

Data regarding the prevalence of chronic spontaneous urticaria (CSU) in childhood-onset systemic lupus erythematosus (cSLE) patients and possible associated factors are limited to a few case reports. The objectives of this study were to assess CSU in a large cSLE population, in order to evaluate the demographic data, clinical manifestations, disease activity/damage, laboratory abnormalities and treatment. A retrospective multicenter cohort study (Brazilian cSLE group) was performed in 10 Pediatric Rheumatology services and included 852 cSLE patients. CSU was diagnosed according to the guidelines of the European Academy of Allergy and Clinical Immunology, the Global Allergy and Asthma European Network, the European Dermatology Forum and the World Allergy Organization. Patients with CSU (evaluated at urticaria diagnosis) and patients without CSU (evaluated at the last visit) were assessed for lupus clinical/laboratory features and treatment. CSU was observed in 10/852 cSLE patients (1.17%). The median of cSLE duration at urticaria diagnosis was 0 (-3 to 5) years. Comparison of cSLE patients with and without CSU revealed a greater frequency of constitutional symptoms (40 vs. 8%, p = 0.006), reticuloendothelial system involvement (30 vs. 3%, p = 0.003), mucocutaneous (90 vs. 28%, p < 0.0001) and musculoskeletal manifestations (50 vs. 6%, p < 0.0001) and methylprednisolone pulse therapy use (60 vs. 9%, p < 0.0001) in the former group. The frequency of immunosuppressive treatment was lower in patients with CSU (p = 0.018). The median SLE Disease Activity Index 2000 (12 vs. 2, p < 0.0001) and erythrocyte sedimentation rate (40 vs. 19 mm/1st hour, p = 0.024), was higher in patients with CSU. To our knowledge, this is the first study with evidence that CSU may be linked to cSLE. We also demonstrated that this particular skin manifestation occurs predominantly at disease onset and is associated with lupus moderate/high disease activity without major organ involvement1673186192CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ301805/2013-0; 2009/51897-5; 302724/2011-

Activation of leukocyte rolling by the cysteine-rich domain and the hyper-variable region of HF3, a snake venom hemorrhagic metalloproteinase

AbstractThe functionality of the disintegrin-like/cysteine-rich domains of snake venom metalloproteinases (SVMPs) has been shown to reside in the cysteine-rich region, which can interact with VWA-containing proteins. Recently, the hyper-variable region (HVR) of the cysteine-rich domain was suggested to constitute a potential protein–protein adhesive interface. Here we show that recombinant proteins of HF3, a hemorrhagic P-III SVMP, containing the cysteine-rich domain (disintegrin-like/cysteine-rich and cysteine-rich proteins) but not the disintegrin-like protein were able to significantly increase leukocyte rolling in the microcirculation. Peptides from the HVR also promoted leukocyte rolling and this activity was inhibited by anti-alphaM/beta2 antibodies. These results show, for the first time, that the cysteine-rich domain and its HVR play a role in triggering pro-inflammatory effects mediated by integrins

Early exposure to high-sucrose diet leads to deteriorated ovarian health

Background: The metabolic syndrome (MetS) is correlated with disorders of the reproductive system, such as the polycystic ovary syndrome (PCOS). While consumption of a diet rich in carbohydrates is linked to the development of MetS, it is still unclear if this diet leads to ovarian dysfunction and PCOS. Objectives: We investigated the influence of a high-sucrose diet (HSD) on the ovarian milieu of Wistar rats and studied the correlation between high consumption of sugary drink and the prevalence of PCOS in women. Methods: Wistar rats were given standard laboratory diet (CTR, 10% sucrose, n = 8) or HSD (HSD, 25% sucrose, n = 8) from postnatal day 21 to 120. The animals were evaluated weekly to calculate food intake, feed efficiency and weight gain. Both onset of puberty and estrous cycle were monitored. Metabolic serum biochemistry, organ morphometry and ovarian histology were performed upon euthanasia. In parallel, fixed-effects multiple linear regression analysis was carried out using data from Brazilian states (459 state-year observations) to test the correlation between the consumption of sugar-sweetened beverages and the prevalence of PCOS. Results: HSD animals were not obese, but showed increased adipose tissue accumulation, hyperglycaemia and insulin resistance when compared to CTR. Interestingly HSD rats also entered puberty earlier than CTR. Moreover, ovaries from HSD animals had an increased number of atretic antral follicles and cystic follicles, which were correlated with hypertrophy of periovarian adipocytes. Finally, there was a positive correlation between the intake of sugary drinks and prevalence of PCOS in women of reproductive age. Conclusions: HSD ingestion leads to ovarian dysfunction in rats and could be correlated with PCOS in women, suggesting these alterations could lead to public health issues. Therefore, we reinforce the deleterious impact of HSD to the ovarian system and suggest that the reduction of added sugars intake could be beneficial to ovarian health

The TAL Effector PthA4 Interacts with Nuclear Factors Involved in RNA-Dependent Processes Including a HMG Protein That Selectively Binds Poly(U) RNA

Plant pathogenic bacteria utilize an array of effector proteins to cause disease. Among them, transcriptional activator-like (TAL) effectors are unusual in the sense that they modulate transcription in the host. Although target genes and DNA specificity of TAL effectors have been elucidated, how TAL proteins control host transcription is poorly understood. Previously, we showed that the Xanthomonas citri TAL effectors, PthAs 2 and 3, preferentially targeted a citrus protein complex associated with transcription control and DNA repair. To extend our knowledge on the mode of action of PthAs, we have identified new protein targets of the PthA4 variant, required to elicit canker on citrus. Here we show that all the PthA4-interacting proteins are DNA and/or RNA-binding factors implicated in chromatin remodeling and repair, gene regulation and mRNA stabilization/modification. The majority of these proteins, including a structural maintenance of chromosomes protein (CsSMC), a translin-associated factor X (CsTRAX), a VirE2-interacting protein (CsVIP2), a high mobility group (CsHMG) and two poly(A)-binding proteins (CsPABP1 and 2), interacted with each other, suggesting that they assemble into a multiprotein complex. CsHMG was shown to bind DNA and to interact with the invariable leucine-rich repeat region of PthAs. Surprisingly, both CsHMG and PthA4 interacted with PABP1 and 2 and showed selective binding to poly(U) RNA, a property that is novel among HMGs and TAL effectors. Given that homologs of CsHMG, CsPABP1, CsPABP2, CsSMC and CsTRAX in other organisms assemble into protein complexes to regulate mRNA stability and translation, we suggest a novel role of TAL effectors in mRNA processing and translational control