Cadmium (Cd) is highly toxic to most organisms, but some rare plant species can hyperaccumulate Cd in aboveground tissues without suffering from toxicity. The mechanism underlying Cd detoxification ...by hyperaccumulators is interesting but unclear.
Here, the heavy metal ATPase 3 (SpHMA3) gene responsible for Cd detoxification was isolated from the Cd/zinc (Zn) hyperaccumulator Sedum plumbizincicola. RNA interference (RNAi)-mediated silencing and overexpression of SpHMA3 were induced to investigate its physiological functions in S. plumbizincicola and a nonhyperaccumulating ecotype of Sedum alfredii.
Heterologous expression of SpHMA3 in Saccharomyces cerevisiae showed Cd-specific transport activity. SpHMA3 was highly expressed in the shoots and the protein was localized to the tonoplast. The SpHMA3-RNAi lines were hypersensitive to Cd but not to Zn, with the growth of shoots and young leaves being severely inhibited by Cd. Overexpressing SpHMA3 in the nonhyperaccumulating ecotype of S. alfredii greatly increased its tolerance to and accumulation of Cd, but not Zn.
These results indicate that elevated expression of the tonoplast-localized SpHMA3 in the shoots plays an essential role in Cd detoxification, which contributes to the maintenance of the normal growth of young leaves of S. plumbizincicola in Cd-contaminated soils.
Implementing selective-area p-type doping through ion implantation is the most attractive choice for the fabrication of GaN-based bipolar power and related devices. However, the low activation ...efficiency of magnesium (Mg) ions and the inevitable surface decomposition during high-temperature activation annealing process still limit the use of this technology for GaN-based devices. In this work, we demonstrate successful p-type doping of GaN using protective coatings during a Mg ion implantation and thermal activation process. The p-type conduction of GaN is evidenced by the positive Seebeck coefficient obtained during thermopower characterization. On this basis, a GaN p-i-n diode is fabricated, exhibiting distinct rectifying characteristics with a turn-on voltage of 3 V with an acceptable reverse breakdown voltage of 300 V. Electron beam induced current (EBIC) and electroluminescent (EL) results further confirm the formation of p-type region due to Mg ion implantation and subsequent thermal activation. This repeatable and uniform manufacturing process can be implemented in mass production of GaN devices for versatile power and optoelectronic applications.
Neuronal intranuclear inclusion disease (NIID) is a slowly progressing neurodegenerative disease characterized by eosinophilic intranuclear inclusions in the nervous system and multiple visceral ...organs. The clinical manifestation of NIID varies widely, and both familial and sporadic cases have been reported. Here we have performed genetic linkage analysis and mapped the disease locus to 1p13.3-q23.1; however, whole-exome sequencing revealed no potential disease-causing mutations. We then performed long-read genome sequencing and identified a large GGC repeat expansion within human-specific NOTCH2NLC. Expanded GGC repeats as the cause of NIID was further confirmed in an additional three NIID-affected families as well as five sporadic NIID-affected case subjects. Moreover, given the clinical heterogeneity of NIID, we examined the size of the GGC repeat among 456 families with a variety of neurological conditions with the known pathogenic genes excluded. Surprisingly, GGC repeat expansion was observed in two Alzheimer disease (AD)-affected families and three parkinsonism-affected families, implicating that the GGC repeat expansions in NOTCH2NLC could also contribute to the pathogenesis of both AD and PD. Therefore, we suggest defining a term NIID-related disorders (NIIDRD), which will include NIID and other related neurodegenerative diseases caused by the expanded GGC repeat within human-specific NOTCH2NLC.
A new approach is proposed for the planar array failure diagnosis from a set of far-field measurements. Under the framework of Bayesian learning, a Bernoulli-Gaussian (BG) model is constructed to ...exploit the binary prior information of the unknown failure elements. Subsequently, the variational expectation maximization (EM) strategy is used to perform the Bayesian inference. Moreover, the damped generalized approximate message passing (GAMP) is further adopted to circumvent the matrix inversion in the variational EM procedure, thus making the overall process computationally very efficient. A set of representative numerical experiments are provided to validate the accuracy, efficiency, and flexibility of the proposed method.
An intumescent flame retardant, poly(diaminodiphenyl methane spirocyclic pentaerythritol bisphosphonate) (PDSPB) has been covalently grafted onto the surfaces of multiwalled carbon nanotubes (MWNTs) ...to obtain MWNT‐PDSPB and according nanocomposites were prepared via melt blending. After high density PDSPB (65 wt %) were attached to the MWNTs, core‐shell nanostructures with MWNTs as the hard core and PDSPB as the soft shell were formed. The resultant MWNT‐PDSPB was soluble and stable in polar solvents, such as DMF. The optical microscopy and TEM results showed that the functionalized MWNTs can achieve better dispersion in ABS matrix. The linear viscoelastic behavior indicated that MWNT‐PDSPB can form network structure at very low nanotube loading than un‐functionalized MWNTs. The results of flammability showed that better flame retardancy was obtained for ABS/MWNT‐PDSPB nanocomposites due to the better dispersion of MWNT‐PDSPB in ABS matrix. The flammability of the composites is strongly dependent on the network structure of nanotubes which reduces the diffusion of volatile combustible fragments generated by polymer degradation which diffuse towards the surface of the burning polymer to evaporate to feed the flame. The grafting of intumescent flame retardant of PDSPB can improve both the dispersion of nanotubes in polymer matrix and flame retardancy of the nanocomposites.
An intumescent flame retardant, PDSPB has been covalently grafted onto the surfaces of multiwalled carbon nanotubes (MWNTs). The combination of PDSPB and MWNTs can improve both the dispersion of nanotubes in the polymer matrix and the flame retardancy of the nanocomposites.
High‐risk (HR) human papillomavirus (HPV) prevalence has been shown to correlate well with cervical cancer incidence rates. Our study aimed to estimate the prevalence of HR‐HPV and cervical ...intraepithelial neoplasia (CIN) in China and indirectly informs on the cervical cancer burden in the country. A total of 30,207 women from 17 population‐based studies throughout China were included. All women received HPV DNA testing (HC2, Qiagen, Gaithersburg, MD), visual inspection with acetic acid and liquid‐based cytology. Women positive for any test received colposcopy‐directed or four‐quadrant biopsies. A total of 29,579 women had HR‐HPV testing results, of whom 28,761 had biopsy confirmed (9,019, 31.4%) or assumed (19,742, 68.6%) final diagnosis. Overall crude HR‐HPV prevalence was 17.7%. HR‐HPV prevalence was similar in rural and urban areas but showed dips in different age groups: at age 25–29 (11.3%) in rural and at age 35–39 (11.3%) in urban women. In rural and urban women, age‐standardized CIN2 prevalence was 1.5% 95% confidence interval (CI): 1.4–1.6% and 0.7% (95% CI: 0.7–0.8%) and CIN3+ prevalence was 1.2% (95% CI: 1.2–1.3%) and 0.6% (95% CI: 0.5–0.7%), respectively. Prevalence of CIN3+ as a percentage of either all women or HR‐HPV‐positive women steadily increased with age, peaking in 45‐ to 49‐year‐old women. High prevalence of HR‐HPV and CIN3+ was detected in both rural and urban China. The steady rise of CIN3+ up to the age group of 45–49 is attributable to lack of lesion removal through screening. Our findings document the inadequacy of current screening in China while indirectly raising the possibility that the cervical cancer burden in China is underreported.
Breast cancer 1 (BRCA1) and autophagy both play a significant role in drug resistance. However, little is known about the dynamic cross talk between BRCA1 and autophagy in the regulation of drug ...sensitivity. Here, we investigated the drug resistance‐associated regulation of BRCA1 in epithelial ovarian cancer stem cells (EOCSCs). The results indicated that BRCA1 could regulate drug resistance in EOCSCs. Autophagy played a significant role in the stemness maintenance and was a key mechanism underlying the survival against chemotherapy in EOCSCs. Further investigation found that BRCA1 could regulate drug resistance of EOCSCs through autophagy. Meanwhile, changes in the level of autophagy provided feedback regarding the expression of BRCA1. Inhibition of autophagy activity could effectively reduce the resistance of EOCSCs caused by BRCA1. In addition, BRCA1 was able to regulate cellular apoptosis and cell cycle progression under the action of cisplatin through autophagy, indirectly affecting the drug sensitivity of EOCSCs. The present results highlight a novel relationship between BRCA1 and autophagy, which may provide insight into the etiology of BRCA1‐associated ovarian cancer, and improve our understanding of resistance mechanisms in ovarian cancer.
Autophagy played a significant role in the stemness maintenance and was a key mechanism underlying the survival against chemotherapy in epithelial ovarian cancer stem cells (EOCSCs). Breast cancer 1 (BRCA1) could regulate drug resistance of EOCSCs through autophagy. Meanwhile, changes in the level of autophagy provided feedback regarding the expression of BRCA1.
Splicing factor SRSF3 is an oncogene and overexpressed in various kinds of cancers, however, the function and mechanism involved in colorectal cancer (CRC) remained unclear. The aim of this study was ...to explore the relationship between SRSF3 and carcinogenesis and progression of CRC.
The expression of SRSF3 in CRC tissues was detected by immunohistochemistry. The proliferation and invasion rate was analyzed by CCK-8 assay, colony formation assay, transwell invasion assay and xenograft experiment. The expression of selected genes was detected by western blot or real time PCR.
SRSF3 is overexpressed in CRC tissues and its high expression was associated with CRC differentiation, lymph node invasion and AJCC stage. Upregulation of SRSF3 was also associated with shorter overall survival. Knockdown of SRSF3 in CRC cells activated ArhGAP30/Ace-p53 and decreased cell proliferation, migration and survival; while ectopic expression of SRSF3 attenuated ArhGAP30/Ace-p53 and increases cell proliferation, migration and survival. Targeting SRSF3 in xenograft tumors suppressed tumor progression in vivo.
Taken together, our data identify SRSF3 as a regulator for ArhGAP30/Ace-p53 in CRC, and highlight potential prognostic and therapeutic significance of SRSF3 in CRC.
The poor corrosion resistance of magnesium–lithium alloy surface works against its application in aerospace, automobile, electronics, etc. In this research, some kinds of non-toxic and non-polluting ...rare earth and silane (RE–Si) composite conversion coatings were built up on Mg–Li alloy surface, and formation process of coatings was investigated. The parameters for coating preparation were determined, including immersion time and temperature, pH value of conversion solution and curing time. The optimized technological parameters for preparation of RE–Si composite coating were finally confirmed. The influence of doping nanoparticles on RE–Si composite coating was also discussed, and the microstructure of coatings shows that the addition of nanoparticles can effectively improve the compactness and uniformity of composite coating. The corrosion resistance of specimens with RE–Si composite conversion coating is improved to a great extent compared with those of substrate or specimens with single rare earth (RE) conversion coating or with silane coating. The result also indicates that corrosion resistance of RE–Si composite coating doping with nanoparticles is further improved. Composition of the composite coatings was analyzed, and the effect of RE elements and silane on coating formation process was investigated. Corrosion resistance mechanism of composite coatings on Mg–Li alloy surface was discussed.
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