Mechanistic insights into dioxygen activation by a manganese corrole complex: a broken-symmetry DFT study

The Mn–oxygen species have been implicated as key intermediates in various Mn-mediated oxidation reactions. However, artificial oxidants were often used for the synthesis of the Mn–oxygen intermediates. Remarkably, the Mn(v)–oxo and Mn(iv)–peroxo species have been observed in the activation of O₂ by Mn(iii) corroles in the presence of base (OH⁻) and hydrogen donors. In this work, density functional theory methods were used to get insight into the mechanism of dioxygen activation and formation of Mn(v)–oxo. The results demonstrated that the dioxygen cannot bind to Mn without the axial OH⁻ ligand. Upon the addition of the axial OH⁻ ligand, the dioxygen can bind to Mn in an end-on fashion to give the Mn(iv)–superoxo species. The hydrogen atom transfer from the hydrogen donor (substrate) to the Mn(iv)–superoxo species is the rate-limiting step, having a high reaction barrier and a large endothermicity. Subsequently, the O–C bond formation is concerted with an electron transfer from the substrate radical to the Mn and a proton transfer from the hydroperoxo moiety to the nearby N atom of the corrole ring, generating an alkylperoxo Mn(iii) complex. The alkylperoxo O–O bond cleavage affords a Mn(v)–oxo complex and a hydroxylated substrate. This novel mechanism for the Mn(v)–oxo formation via an alkylperoxo Mn(iii) intermediate gives insight into the O–O bond activation by manganese complexes.

DFT calculations revealed a novel mechanism for the formation of Mn(v)–oxo in the dioxygen activation by a Mn(iii) corrole complex involving a Mn(iii)–alkylperoxo intermediate.     

The Difficult Task of Diagnosing Depression in Elderly People with Cancer: A Systematic Review

Background:Depression is a common psychiatric problem in the elderly and oncology patients. In elderly people with cancer, depression has a peculiar phenomenology. It has a significant impact on the quality of life. Moreover, it is associated with poor adherence to treatments, increased risk of suicide, and mortality. Nevertheless, the topic of depression in elderly people with cancer remains unexplored.Objective:The main goal of this article is to review the literature from the past 20 years on the relationships between depression, cancer, and aging.Methods:The methods followed the Prisma model for eligibility of studies. The articles in which the keywords “depression”, “cancer”, “ elderly, aging, or geriatric” were present, either in the text or in the abstract, were selected. 8.056 articles, by matching the keywords “depression and elderly and cancer,” were identified. Only 532 papers met the eligibility criteria of search limits and selection process. Out of 532 papers, 467 were considered irrelevant, leaving 65 relevant studies. Out of 65 suitable studies, 39 (60.0%) met our quality criteria and were included.Results:The risk factors associated with depression in elderly people with cancer can be divided into 4 groups: 1) tumor-related; 2) anticancer treatment-related; 3) patients-related; 4) number and type of comorbidity. The main obstacles in diagnosing depression in elderly patients with cancer are the overlap of the symptoms of cancer and side effects of treatment with the symptoms of depression but also the different ways of reporting depressive symptoms of elderly people and the different clinical types of depression. There is a lack of data regarding validated scales to assess depression in geriatric patients with cancer. Any mental illness, specifically co-occurring anxiety and depression, increases the risk of diagnosis delay and anticancer treatment adherence. Cancer and the diagnosis of mental disorders prior to cancer diagnosis correlate with an increased risk for suicide. A non-pharmacological therapeutic approach, pharmacological treatment and/or a combination of both can be used to treat elderly patients with cancer, but a detailed analysis of comorbidities and the assessment of polypharmacy is mandatory in order to avoid potential side-effects and interactions between antidepressants and the other drugs taken by the patients.Conclusion:Future research should be conducted with the aim of developing a modified and adapted assessment method for the diagnosis and treatment of depression in elderly people with cancer in order to improve their clinical outcomes and quality of life.     

The alterations of degree centrality in the frontal lobe of patients with panic disorder

Objective: The brain network in panic disorder (PD) is still an intriguing issue for research. In this study, we hoped to investigate the role of DC (degree centrality) for the pathophysiology of PD, especially for the fear network.Methods: We enrolled 60 patients with PD and 60 controls in the current study. The gender and age were matched for two groups. All participants received the resting-state functional magnetic resonance imaging to survey the baseline brain activity. Then the DC values of all participants were using REST toolbox. We also compared the DC values between PD and controls. The statistical threshold was set as FDR (false discovery rate) < 0.05.Results: The DC values were significantly lower in the right superior frontal gyrus of PD patients compared to controls (FDR < 0.05). In addition, a negative correlation between the DC values and panic severity was observed in the right superior frontal gyrus and left inferior frontal gyrus. However, there was no significant association between the DC values and illness duration.Conclusion: The DC seemed significantly altered in the frontal lobe of PD patients. The role of the frontal lobe might be more emphasized in the pathophysiology research for PD.     

Significance of the lncRNAs MALAT1 and ANRIL in occurrence and development of glaucoma

BackgroundPrimary open‐angle glaucoma (POAG) is the commonest form of glaucoma which is estimated to cause bilaterally blind within 11.1 million people by 2020. Therefore, the primary objectives of this study were to investigate the clinical significance of single‐nucleotide polymorphisms (SNPs) in the lncRNAs MALAT1 and ANRIL in a Chinese Han POAG cohort.MethodsThree hundred and forty‐six glaucoma patients and 263 healthy controls were recruited, and totally 14 SNPs in MALAT1 and ANRIL were genotyped between the two populations.ResultsThe MALAT1 SNPs rs619586 (A>G), rs3200401 (C>T), and rs664589 (C>G) were associated with POAG risk, and the ANRIL SNPs rs2383207 (A>G), rs564398 (A>G), rs2157719 (A>G), rs7865618 (G>A), and rs4977574 (A>G) were associated with POAG (p < 0.05). The MALAT1 haplotypes ACG and ATC, comprised rs619586, rs3200401, and rs664589, increased POAG risk, and the ANRIL haplotype AAGAA, made up of rs2383207, rs7865618, rs4977574, rs564398, and rs2157719, show a significantly increased risk of POAG. In addition, rs619586 (A>G) of MALAT1 and rs564398/rs2157719 of ANRIL were associated with a smaller vertical cup‐to‐disc ratio, while rs619586 of MALAT1 and rs2383207/rs4977574 of ANRIL were associated with higher intraocular pressure in the POAG population.ConclusionSingle‐nucleotide polymorphisms and haplotypes in ANRIL and MALAT1 were associated with POAG onset in our study population, which provide more possibilities to POAG diagnosis and treatment.     

Retrograde nerve growth factor signaling modulates tooth mechanical hyperalgesia induced by orthodontic toothmovement via acid-sensing ion channel 3

INTRODUCTION Orofacial pain, with a prevalence of 16％ among general population,1 is a constellation of painful conditions in the orofacial regions and comprises...     

Factor analysis approach unveils the influencing factors of dandruff in the normal teenage population

The aim of this study was to explore the main factors affecting the occurrence of dandruff in healthy people (nondisease‐induced scalp desquamation). This study analyzed the fungal microbial diversity of the scalp in Chinese teenage volunteers and measured scalp sebum secretion, the scalp pH value, and scalp transepidermal water loss. The amount and size of dandruff were measured, and the main factors that influence dandruff in the normal population were identified using principal component analysis. The results showed that an increase in Malassezia restricta led to an increased amount of dandruff in the mild and moderate groups. Conversely, this was not found for individuals in the severe group, whose dandruff symptoms were influenced by scalp barrier function. In terms of dandruff area grouping, the pH value and the amount of sebum secretion were the main factors, with the barrier function and microbial diversity being secondary factors. Dandruff cosmetics should emphasize different treatments for different types of dandruff to achieve better antidandruff effects. The results of this study provide a new theoretical basis for the development of multiple targets for antidandruff agents aimed at the normal population.