This study explores different perceptions of pre-service and beginning teachers’ professional identity in relation to their decisions to leave the profession. Teachers’ professional identity was ...further broken down into six factors: value, efficacy, commitment, emotions, knowledge and beliefs, and micropolitics. This study employed mixed-methods which included 84 participant surveys, and 27 interviews from four groups of participants at different stages of teaching. The findings of this study showed that pre-service teachers tended to have naïve and idealistic perceptions of teaching, and dropout teachers showed most emotional burnout. Implications for improvement of teacher education and retention of beginning teachers are discussed.
With the increasing concern about the high attrition rate among beginning teachers, it is essential that we come to a better understanding of why teachers leave the profession. This study explored ...differences between leavers and stayers in terms of the process of their resilience responses. Major psychological factors such as value, self-efficacy, beliefs and emotions were foregrounded to understand how leavers and stayers are similar or different in negotiating and interpreting external environments. This study employed semi-structured interviews for seven leavers and seven stayers who had teaching experiences of less than five years. The findings of this study showed that both leavers and stayers had intrinsic interests in working as a teacher. Also, both groups identified similar challenges of working as a teacher, such as classroom management and effective delivery of lessons. However, leavers showed weaker self-efficacy beliefs than stayers, who tended to get more support and help from school administrators. In addition, leavers held beliefs that imposed heavy burdens on themselves, which may have created stress and emotional burnout. Unlike leavers, stayers often reported their strategies to prevent them from being burned out by setting boundaries establishing relationship with students. Given the high attrition rate of beginning teachers, the current study provides meaningful insight about challenges beginning teachers' face, their needs and better ways to prepare and train them.
A gut feeling Sze, Ji Y
Nature chemical biology,
02/2023, Letnik:
19, Številka:
2
Journal Article
Recenzirano
Unbiased metabolomics revealed the conversion of serotonin into N-acetylserotonin-derived glucosides by an intestinal carboxylesterase in Caenorhabditis elegans, which suggests an unappreciated role ...of the gut in modulating 5-HT signaling.
To understand the impact of firework-burning (FW) particles on air quality and human health during the winter haze period, 39 elements, 10 water-soluble ions and 8 fractions of carbonaceous species ...in atmospheric PM2.5 in Nanjing were investigated during the 2014 Chinese Spring Festival (SF). Serious regional haze pollution persisted throughout the entire sampling period, with PM2.5 averaging at 113 plus or minus 69 mu g m-3 and visibility at 4.8 plus or minus 3.2 km. The holiday effect led to almost all the chemical species decreasing during the SF, except for Al, K, Ba and Sr which were related to FW. The source contributions of coal combustion, vehicle emission and road dust decreased dramatically, whereas FW contributed to about half of the PM2.5 during the SF period. The intensive emission of FW particles on New Year's Eve accounted for 60.1% of the PM2.5. Fireworks also obviously modified the chemical compositions of PM2.5, with 39.3% contributed by increased organic matter, followed by steadily increased loadings of secondary inorganic ions. The aging processes of the FW particles lasted for about 4 days reflected by the variations of Ba, Sr, NH super(+) sub(4), NO super(-) sub(3), SO sub(4) super(2-) and K super(+), characterized by heterogeneous reactions of SO sub(2) and NO sub(x) on crustal materials directly from FW, the replacement of Cl super(-) by NO super(-) sub(3) and SO sub(4) super(2-), coating of NO super(-) sub(3) and SO sub(4) super(2-) on soot, formation of secondary organic aerosols and metal-catalyzed formation of NO super(-) sub(3) and SO sub(4) super(2-) at higher relative humidity. During aging, the main contributors to the extinction coefficient shifted from elemental carbon and organic matter to ammonium sulfate. The particles raised higher cancer risk of 1.62 x 10 super(-6) by heavy metals (especially for Cd and As). This study provided detailed composition data and first comprehensive analysis of the aging processes of FW particles during the serious haze pollution period and their potential impact on human health.
N6-methyladenosine (m6A) is a eukaryotic messenger RNA modification catalyzed by methyltransferase-like 3 (METTL3), which is involved in various developmental and disease processes. However, the ...connection between the epigenetic modification of m6A and glucose metabolism during osteogenesis is still unclear. Here, we show that interference with METTL3 in dental pulp stem cells (DPSCs) inhibits cell proliferation and osteogenic differentiation. Moreover, transcriptome sequencing and metabolic testing were used to explore the mechanism between glucose metabolism and m6A modification in METTL3-knockdown DPSCs. Methylated RNA immunoprecipitation–quantitative polymerase chain reaction and RNA stability assays were used to determine the target genes of METTL3. Mechanistically, METTL3 directly interacts with ATP citrate lyase (ACLY) and a mitochondrial citrate transporter (SLC25A1) and then further affects the glycolytic pathway. M6A-mediated ACLY and SLC25A1 stability depends on the m6A readers IGF2BP2 and IGF2BP2/3, respectively. Our experiments uncovered the potential molecular mechanism of epigenetic modification in osteogenic differentiation, providing new ideas for the clinical application of stem cells and the intervention of metabolic bone diseases.
As an emerging alternative cementitious binder, alkali activated slag (AAS) is gaining great attention, but considerable shrinkage caused by alkali activation and drying limit its potential ...applications. Herein, we demonstrate that the addition of an environmentally benign biofilm, cultured from B. subtilis, mitigates both the autogenous and drying shrinkage of AAS. The influences of the biofilm on the hydration kinetics, water absorption and strengths are investigated. Results show the addition of the biofilm increases the hydrophobicity of the pore wall, which in turn decreases the capillary tension. The hydrophobic modification by the biofilm significantly reduces the water loss from the AAS to its direct environment (up to 86% at 35 d exposure). Consequently, both autogenous and drying shrinkage of AAS are dramatically reduced. Moreover, a new mechanism is proposed to explain the mitigation of AAS shrinkage, which takes into account the increase in internal RH and reduction in capillary pressure.
Chimeric antigen receptor (CAR)-T cell therapy has shown remarkable clinical efficacy against B-cell malignancies, yet marked vulnerability to antigen escape and tumor relapse exists. Here we report ...the rational design and optimization of bispecific CAR-T cells with robust activity against heterogeneous multiple myeloma (MM) that is resistant to conventional CAR-T cell therapy targeting B-cell maturation antigen (BCMA). We demonstrate that BCMA/CS1 bispecific CAR-T cells exhibit superior CAR expression and function compared to T cells that co-express individual BCMA and CS1 CARs. Combination therapy with anti-PD-1 antibody further accelerates the rate of initial tumor clearance in vivo, while CAR-T cell treatment alone achieves durable tumor-free survival even upon tumor re-challenge. Taken together, the BCMA/CS1 bispecific CAR presents a promising treatment approach to prevent antigen escape in CAR-T cell therapy against MM, and the vertically integrated optimization process can be used to develop robust cell-based therapy against novel disease targets.
An airborne survey system named the MARK-A1 was developed to be mounted on a commercial drone for the purpose of application in contaminated areas with high dose rate levels. The MARK-A1 system ...consists of a CZT detector, signal processing unit, and positioning and interface units to a PC on the ground. The weight of the system is below 1 kg for loading on a commercial drone. For experimental verification, irradiation testing and field testing were conducted. From the irradiation test, we derived the G-factor and dose rate calibration factor to calculate ambient dose rates from measured energy spectra with an applicable energy range. An airborne survey was then conducted to check the system performance at a height of about 1 m and 10 m. The ambient dose rate was successfully estimated from the calculation of the measured energy spectra and dose conversion factor. Finally, the results were compared with those from in situ gamma-ray spectrometry using a tripod at the same survey site. The difference between the two systems was below 20%, indicating a good performance of the MARK-A1. It is anticipated that the MARK-A1 can be used to quickly scan wide, highly contaminated areas that are difficult for humans to access in the event of a radiological accident.
Acephalic spermatozoa is a rare teratozoospermia associated with male infertility. However, the pathogenesis of this disorder remains unclear. Here, we report a 27 years old infertile male from a ...consanguineous family, who presented with 99% headless sperm in his ejaculate. Electron microscopic and immunofluorescence analysis suggested breakage at the midpiece of the patient's sperm cells. Subsequent whole‐exome sequencing analysis identified a homozygous deletion within TSGA10 (c.211delG; p.A71Hfs*12), which resulted in the production of truncated TSGA10 protein. TSGA10 is a testis‐specific protein that localized to the midpiece in the spermatozoa of a normal control; however, immunostaining failed to detect TSGA10 protein in the patient's sperm. Western blot analysis also showed complete absence of TSGA10 protein in the patient. One cycle of in vitro fertilization‐assisted reproduction was conducted, but pregnancy was not achieved after embryo transfer, possibly due to poor embryo quality. Therefore, we speculate that the presence of rare sequence variants within TSGA10 may be associated with acephalic spermatozoa in humans.
Acephalic spermatozoa due to biallelic TSGA10 mutation.
Adipose-derived mesenchymal stem cells (ASCs) represent an excellent candidate for tissue engineering due to their multipotency and paracrine functions. Physical cues provided by the scaffolds have ...been shown to direct a variety of cellular behaviors of ASCs; however, their effects on the paracrine functions of ASCs, especially immunomodulatory functions, remain largely unexplored. Thus, PLLA electrospun fibrous scaffolds, with fibers oriented either randomly or aligned, were used as a model to investigate the effects of fiber orientation on the immunomodulatory paracrine secretion of ASCs. ASCs cultured on aligned fibers produced significantly higher levels of immunomodulatory factors than those cultured on random fibers. By using the conditioned media from ASCs cultured on aligned fibers, the enhanced immunomodulatory functions of ASCs were confirmed by the M2 phenotypic change seen in macrophages. The enhanced immunomodulation of ASCs correlated with the activation of FAK signaling, as evidenced by a decreased production of immunomodulatory factors in ASCs after treatment with inhibitors of the FAK pathway. In addition, aligned fibers promoted the activation of YAP signaling in ASCs. The inhibited immunomodulatory properties of ASCs by a YAP inhibitor indicated that YAP signaling was also involved in mediating the increased immunomodulatory functions of ASCs on aligned fibers. Our findings identify both FAK and YAP/TAZ signaling as required mechanotransduction pathways through which aligned fibers stimulate the immunomodulatory function of ASCs and highlight fiber orientation as a key design parameter for immunomodulatory fibrous engineered scaffolds.
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