The photoreaction of an N-Boc secondary amine and N-Boc N-methyl α-amino acid ester with acrylonitrile using inexpensive two-molecule photoredox catalysts results in the production of α-alkylated ...amine through the generation of an α-carbamy radical under mild conditions. In particular, this mothed leads to a regioselective modification of N-Boc N-methyl α-amino acid ester with the retention of α-chirality through the generation of the less stable primary α-carbamyl radical.
Reeves' Turtles (also known as Chinese Three-Keeled Pond Turtles, Mauremys reevesii) exhibit temperature-dependent sex determination (TSD). Recent studies reported genome sequencing and described ...normal embryonic and gonadal developmental patterns in M. reevesii, making them a promising model for studying TSD. Nevertheless, development of other reproductive organs, such as the Müllerian duct, has not been described in this species. The Müllerian duct is a tubular structure that primarily forms in mesonephros during embryogenesis in both sexes. While the Müllerian duct further develops into the reproductive tract in females, it typically regresses in males. In this study, we investigated the development and regression of the Müllerian duct in M. reevesii during the latter half of embryogenesis under female- (FPT; 318C) and male-producing temperatures (MPT; 268C). Histological analysis revealed that the Müllerian duct showed the first sign of regression at the end of the temperature-sensitive period under MPT and significantly regressed at the prehatching stage (stage 24). Development and regression of the Müllerian duct in M. reevesii followed general trajectories reported in mouse and chicken studies. Timing of regression was consistent with reports in another TSD turtle, Pond Sliders (Trachemys scripta). Our study provides a basis for comparative studies of reproductive organs in TSD species and for elucidating mechanisms leading to sexual differentiation.
Abstract
Temperature-dependent sex determination (TSD) is a mechanism in which environmental temperature, rather than innate zygotic genotype, determines the fate of sexual differentiation during ...embryonic development. Reeves’ turtle (also known as the Chinese three-keeled pond turtle,
Mauremys reevesii
) exhibits TSD and is the only species whose genome has been determined in Geoemydidae to date. Thus,
M. reevesii
occupy phylogenetically important position for the study of TSD and can be compared to other TSD species to elucidate the underlying molecular mechanism of this process. Nevertheless, neither embryogenesis nor gonadogenesis has been described in this species. Therefore, herein, we investigated the chronology of normal embryonic development and gonadal structures in
M. reevesii
under both female- and male-producing incubation temperatures (FPT 31 °C or MPT 26 °C, respectively). External morphology remains indistinct between the two temperature regimes throughout the studied embryonic stages. However, the gonadal ridges present on the mesonephros at stage 16 develop and sexually differentiate at FPT and MPT. Ovarian and testicular structures begin to develop at stages 18–19 at FPT and stages 20–21 at MPT, respectively, and thus, the sexual differentiation of gonadal structures began earlier in the embryos at FPT than at MPT. Our results suggest that temperature sensitive period, at which the gonadal structures remain sexually undifferentiated, spans from stage 16 (or earlier) to stages 18–19 at FPT and to stages 20–21 at MPT. Understanding the temperature-dependent differentiation in gonadal structures during embryonic development is a prerequisite for investigating molecular basis underlying TSD. Thus, the result of the present study will facilitate further developmental studies on TSD in
M. reevesii
.
Aim
Caregiver burden in dementia is an important issue, but few studies have examined the mental health of younger and older family caregivers by comparing them with age‐ and gender‐matched community ...residents. We aimed to compare the mental health of dementia caregivers with that of community residents and to clarify factors related to mental health problems in younger and older caregivers.
Methods
We studied 104 dementia caregivers; 46 were younger (<65 years) and 58 were older (≥65 years). A total of 104 community residents who were matched for age and gender were selected. We compared depression (Center for Epidemiologic Studies Depression Scale for younger participants; Geriatric Depression Scale for older participants), health‐related quality of life (QOL) short‐form health survey (SF‐8), sleep problems, and suicidal ideation between the caregivers and community residents by age. Behavioural and psychological symptoms of dementia, activities of daily living (ADL), and instrumental ADL were assessed among patients with dementia using the Neuropsychiatric Inventory, Physical Self‐Maintenance Scale, and Lawton Instrumental ADL Scale, respectively.
Results
According to SF‐8 results, both younger and older caregivers had significantly worse mental QOL than community residents (younger caregivers: 46.3 vs community residents: 49.7, P = 0.017; older caregivers: 48.2 vs community residents: 51.1, P = 0.024) but were not more depressive. Sleep problems were significantly more frequent in younger caregivers (39.1%) than in community residents (17.0%) (P = 0.017). Multiple regression analysis revealed that caregivers’ deteriorated mental QOL was associated with patients’ behavioural and psychological symptoms of dementia in younger caregivers and with dementia patients’ instrumental ADL and female gender in older caregivers.
Conclusions
Dementia caregivers had a lower mental QOL than community residents. To maintain caregivers’ mental QOL, it is necessary to provide younger caregivers with skills or professional interventions for dealing with behavioural and psychological symptoms of dementia, and older caregivers must be offered adequate care support.
Malnutrition among dementia patients is an important issue. However, the biochemical markers of malnutrition have not been well studied in this population. The purpose of this study was to compare ...biochemical blood markers among patients with Alzheimer's disease (AD), dementia with Lewy bodies (DLB), and frontotemporal lobar degeneration (FTLD). A total of 339 dementia outpatients and their family caregivers participated in this study. Low serum albumin was 7.2 times more prevalent among patients with DLB and 10.1 times more prevalent among those with FTLD than among those with AD, with adjustment for age. Low hemoglobin was 9.1 times more common in female DLB patients than in female AD patients, with adjustment for age. The levels of biochemical markers were not significantly correlated with cognitive function. Family caregivers of patients with low total protein, low albumin, or low hemoglobin were asked if the patients had loss of weight or appetite; 96.4% reported no loss of weight or appetite. In conclusion, nutritional status was worse in patients with DLB and FTLD than in those with AD. A multidimensional approach, including blood testing, is needed to assess malnutrition in patients with dementia.
Auditory hallucinations are an important symptom for diagnosing dementia with Lewy bodies (DLB), yet they have received less attention than visual hallucinations. We investigated the clinical ...features of auditory hallucinations and the possible mechanisms by which they arise in patients with DLB.
We recruited 124 consecutive patients with probable DLB (diagnosis based on the DLB International Workshop 2005 criteria; study period: June 2007-January 2015) from the dementia referral center of Kumamoto University Hospital. We used the Neuropsychiatric Inventory to assess the presence of auditory hallucinations, visual hallucinations, and other neuropsychiatric symptoms. We reviewed all available clinical records of patients with auditory hallucinations to assess their clinical features. We performed multiple logistic regression analysis to identify significant independent predictors of auditory hallucinations.
Of the 124 patients, 44 (35.5%) had auditory hallucinations and 75 (60.5%) had visual hallucinations. The majority of patients (90.9%) with auditory hallucinations also had visual hallucinations. Auditory hallucinations consisted mostly of human voices, and 90% of patients described them as like hearing a soundtrack of the scene. Multiple logistic regression showed that the presence of auditory hallucinations was significantly associated with female sex (P = .04) and hearing impairment (P = .004). The analysis also revealed independent correlations between the presence of auditory hallucinations and visual hallucinations (P < .001), phantom boarder delusions (P = .001), and depression (P = .038).
Auditory hallucinations are common neuropsychiatric symptoms in DLB and usually appear as a background soundtrack accompanying visual hallucinations. Auditory hallucinations in patients with DLB are more likely to occur in women and those with impaired hearing, depression, delusions, or visual hallucinations.
The Eu(III) distribution mechanism in single extractant-impregnated polymer-layered silica particle in a complex solution containing multiple lanthanide ions was investigated using fluorescence ...microspectroscopy, which was compared with the single-ion distribution system. The rate-determining step of the Eu(III) distribution was the reaction of Eu(III) with the two extractant molecules in the particle. The distribution mechanism and rate constants obtained in the multiple lanthanide ions-distribution system agreed with those of the single-ion distribution system.
Graphical abstract
PDF
