Chemical Exfoliation toward Magnetic 2D VOCl Monolayers

The diversification of magnetic two-dimensional (2D) materials holds the key to the further development of advanced technologies, such as spintronic devices and efficient data storage. However, the search for intrinsic magnetism down to the 2D limit is severely limited by the ability to reliably exfoliate large, air-stable nanosheets. Chemical exfoliation, a relatively underutilized method for delamination, offers many advantages, including a high degree of adaptability and higher yields of uniformly exfoliated materials. van der Waals (vdW) materials, in particular the family of transition-metal oxyhalides, are ideal candidates for chemical exfoliation due to their large interlayer spacing and the wide variety of interesting magnetic properties they exhibit. In this study, we employ a chemical exfoliation method to delaminate the layered antiferromagnet vanadium oxychloride (VOCl) down to the monolayer limit. The resulting nansoheets have lateral sizes of up to 20 μm, are air-stable, and can be easily isolated. Magnetic characterization was performed throughout the exfoliation process, tracking the changes in magnetic behavior among bulk VOCl, its lithiated intercalate, and the restacked nanosheet pellet. The results from this work demonstrate the potential of chemical exfoliation, along with illustrating the effects of low dimensionality on magnetic properties.

Interaction of MyoD and MyoG with Myoz2 gene in bovine myoblast differentiation

This study aims to explore the functional role of Myoz2 in myoblast differentiation, and elucidate the potential factors interact with Myoz2 in promoter transcriptional regulation. The temporal-spatial expression results showed that the bovine Myoz2 gene was highest expressed in longissimus dorsi, and in individual growth stages and myoblast differentiation stages. Knockdown of Myoz2 inhibited the differentiation of myoblast, and negative effect of MyoD, MyoG, MyH and MEF2A expression on mRNA levels. Subsequently, the promoter region of bovine Myoz2 gene with 1.7 Kb sequence was extracted, and then it was set as eight series of deleted fragments, which were ligated into pGL3-basic to detect core promoter regions of Myoz2 gene in myoblasts and myotubes. Transcription factors MyoD and MyoG were identified as important cis-acting elements in the core promoter region (-159/+1). Also, it was highly conserved in different species based on dual-luciferase analysis and multiple sequence alignment analysis, respectively. Furthermore, a chromatin immunoprecipitation (ChIP) analysis combined with site-directed mutation and siRNA interference and overexpression confirmed that the combination of MyoD and MyoG occurred in region -159/+1, and played an important role in the regulation of bovine Myoz2 gene. These findings explored the regulatory network mechanism of Myoz2 gene during the development of bovine skeletal muscle.

Phosphorylation of CENP-R by Aurora B regulates kinetochore-microtubule attachment for accurate chromosome segregation

Error-free mitosis depends on accurate chromosome attachment to spindle microtubules via a fine structure called the centromere that is epigenetically specified by the enrichment of CENP-A nucleosomes. Centromere maintenance during mitosis requires CENP-A-mediated deposition of constitutive centromere-associated network that establishes the inner kinetochore and connects centromeric chromatin to spindle microtubules during mitosis. Although previously proposed to be an adaptor of retinoic acid receptor, here, we show that CENP-R synergizes with CENP-OPQU to regulate kinetochore-microtubule attachment stability and ensure accurate chromosome segregation in mitosis. We found that a phospho-mimicking mutation of CENP-R weakened its localization to the kinetochore, suggesting that phosphorylation may regulate its localization. Perturbation of CENP-R phosphorylation is shown to prevent proper kinetochore-microtubule attachment at metaphase. Mechanistically, CENP-R phosphorylation disrupts its binding with CENP-U. Thus, we speculate that Aurora B-mediated CENP-R phosphorylation promotes the correction of improper kinetochore-microtubule attachment in mitosis. As CENP-R is absent from yeast, we reasoned that metazoan evolved an elaborate chromosome stability control machinery to ensure faithful chromosome segregation in mitosis.

A new classification network for diagnosing Alzheimer's disease in class-imbalance MRI datasets

Automatic identification of Alzheimer's Disease (AD) through magnetic resonance imaging (MRI) data can effectively assist to doctors diagnose and treat Alzheimer's. Current methods improve the accuracy of AD recognition, but they are insufficient to address the challenge of small interclass and large intraclass differences. Some studies attempt to embed patch-level structure in neural networks which enhance pathologic details, but the enormous size and time complexity render these methods unfavorable. Furthermore, several self-attention mechanisms fail to provide contextual information to represent discriminative regions, which limits the performance of these classifiers. In addition, the current loss function is adversely affected by outliers of class imbalance and may fall into local optimal values. Therefore, we propose a 3D Residual RepVGG Attention network (ResRepANet) stacked with several lightweight blocks to identify the MRI of brain disease, which can also trade off accuracy and flexibility. Specifically, we propose a Non-local Context Spatial Attention block (NCSA) and embed it in our proposed ResRepANet, which aggregates global contextual information in spatial features to improve semantic relevance in discriminative regions. In addition, in order to reduce the influence of outliers, we propose a Gradient Density Multiple-weighting Mechanism (GDMM) to automatically adjust the weights of each MRI image via a normalizing gradient norm. Experiments are conducted on datasets from the Alzheimer's Disease Neuroimaging Initiative (ADNI) and Australian Imaging, Biomarker and Lifestyle Flagship Study of Aging (AIBL). Experiments on both datasets show that the accuracy, sensitivity, specificity, and Area Under the Curve are consistently better than for state-of-the-art methods.

[Centromere protein U is highly expressed in colorectal cancer and associated with a poor long-term prognosis]

OBJECTIVE

To analyze the expression of centromere protein U (CENPU) in colorectal cancer and its predictive value for long-term prognosis of the patients.

METHODS

We retrospectively analyzed the data of 102 patients with colorectal cancer undergoing radical resection in our hospital between January, 2005 and December, 2011. The expression level of CENPU in colorectal cancer tissue was detected immunohistochemically, and its association with clinicopathological characteristics of the patients were analyzed. The patients were divided into low expression group (n=51) and high expression group (n=51) based on the median CENPU expression level for analysis the value of CENPU for predicting long-term prognosis of the patients after radical resection of the tumors. In the in vitro study, we constructed colorectal cancer cell lines with CENPU interference and CENPU overexpression by lentiviral transfection and assessed the changes in the proliferation, migration and invasion of the cells using CCK-8 assay and Transwell assay.

RESULTS

The protein expression level of CENPU was significantly higher in colorectal cancer tissues than in the adjacent tissues (P < 0.05) and was positively correlated with the expressions levels of Ki67 (r=0.569, P < 0.05) and VEGF-C (r=0.629, P < 0.05). CENPU expression level in colorectal cancer tissue was closely related with tumor progression and clinicopathological stage of the tumor (P < 0.05). Kaplan-Meier survival analysis showed that the patients with high CENPU expression had significantly decreased postoperative overall survival (χ²=11.155, P < 0.05); Cox multivariate regression analysis suggested that CENPU expression level was an independent risk factor affecting the overall survival of the patients after radical resection (HR=1.848, P < 0.05). The results of cell experiments demonstrated that high CENPU expression significantly promoted the proliferation, migration and invasion of the tumor cells.

CONCLUSION

CENPU is highly expressed in colorectal cancer tissues in closely correlation with tumor progression and may serve as a potential biomarker for evaluating the long-term prognosis of colorectal cancer patients.

2D Covalent Organic Frameworks Toward Efficient Photocatalytic Hydrogen Evolution

Efficiently producing clean energy is of great importance for sustainable development of the environment. Solar-driven water splitting for H₂ evolution has an important role among the renewable energy technologies. Developing high-performance and cost-effective photocatalysts is still a critical task before practical application. 2D Covalent organic frameworks (COFs) as photocatalysts have recently attracted widespread interest thanks to their tunable optical bandgaps, tailor-made functionality, excellent crystallinity, high specific surface area, and good photo- and chemical stability. This Review focuses on the representative progress and remaining challenges in 2D COF-based photocatalysts for hydrogen evolution.

Molybdenum Nitride Porous Prisms with a Strong Plasmon Resonance Effect in the Visible Region for Surface-Enhanced Raman Spectroscopy

In surface-enhanced Raman spectroscopy (SERS) detection, the structure of the Raman-scattering substrate is critical to the sensitivity and stability of the detector. Herein, molybdenum nitride (MoN) porous structures with a well-defined hexagonal prism shape were synthesized via a precursor nitriding route. As a typical metallic transition-metal nitride (TMN), these molybdenum nitride porous hexagonal prisms exhibit a rare strong SPR effect in the visible region, with a resonance peak centered at 534 nm. Benefiting from the strong SPR effect and their huge surface area and porosity, these MoN porous hexagonal prisms exhibit surface-enhanced Raman scattering effects comparable to those of noble metals, with a Raman enhancement factor of 5.5 × 10⁶. More importantly, these MoN SERS substrates exhibit ultrahigh chemical stabilities that noble metal and semiconductor substrates do not possess, which can prevent corrosion by strong acids, alkalis, and high-temperature oxidation.

[Construction of an adenovirus vector expressing engineered splicing factor for regulating alternative splicing of YAP1 in neonatal rat cardiomyocytes]

OBJECTIVE

To construct an adenovirus vector expressing artificial splicing factor capable of regulating alternative splicing of Yap1 in cardiomyocytes.

METHODS

The splicing factors with different sequences were constructed against Exon6 of YAP1 based on the sequence specificity of Pumilio1. The PCR fragment of the artificially synthesized PUF-SR or wild-type PUFSR was cloned into pAd-Track plasmid, and the recombinant plasmids were transformed into E. coli DH5α for plasmid amplification. The amplified plasmids were digested with Pac I and transfected into 293A cells for packaging to obtain the adenovirus vectors. Cultured neonatal rat cardiomyocytes were transfected with the adenoviral vectors, and alternative splicing of YAP1 was detected using quantitative and semi-quantitative PCR; Western blotting was performed to detect the signal of the fusion protein Flag.

RESULTS

The transfection efficiency of the adenovirus vectors was close to 100% in rat cardiomyocytes, and no fluorescent protein was detected in the cells with plasmid transfection. The results of Western blotting showed that both the negative control and Flag-SR-NLS-PUF targeting the YAPExon6XULIE sequence were capable of detecting the expression of the protein fused to Flag. The results of reverse transcription-PCR and PCR demonstrated that the artificial splicing factor constructed based on the 4th target sequence of YAP1 effectively regulated the splicing of YAP1 Exon6 in the cardiomyocytes (P < 0.05).

CONCLUSION

We successfully constructed adenovirus vectors capable of regulating YAP1 alternative splicing rat cardiomyocytes.

Inhibition of SIRT2 promotes APP acetylation and ameliorates cognitive impairment in APP/PS1 transgenic mice

Aging is a primary risk factor for neurodegenerative diseases, such as Alzheimer's disease (AD). SIRT2, an NAD⁺(nicotinamide adenine dinucleotide)-dependent deacetylase, accumulates in the aging brain. Here, we report that, in the amyloid precursor protein (APP)/PS1 transgenic mouse model of AD, genetic deletion of SIRT2 or pharmacological inhibition of SIRT2 ameliorates cognitive impairment. We find that suppression of SIRT2 enhances acetylation of APP, which promotes non-amyloidogenic processing of APP at the cell surface, leading to increased soluble APP-α (sAPPα). We discover that lysines 132 and 134 of the major pathogenic protein β-amyloid (Aβ) precursor are acetylated and that these residues are deacetylated by SIRT2. Strikingly, exogenous expression of wild-type or an acetylation-mimic APP mutant protects cultured primary neurons from Aβ42 challenge. Our study identifies SIRT2-mediated deacetylation of APP on K132 and K134 as a regulated post-translational modification (PTM) and suggests inhibition of SIRT2 as a potential therapeutic strategy for AD.

Progerin modulates the IGF-1R/Akt signaling involved in aging

Progerin, a product of LMNA mutation, leads to multiple nuclear abnormalities in patients with Hutchinson-Gilford progeria syndrome (HGPS), a devastating premature aging disorder. Progerin also accumulates during physiological aging. Here, we demonstrate that impaired insulin-like growth factor 1 receptor (IGF-1R)/Akt signaling pathway results in severe growth retardation and premature aging in Zmpste24^-/- mice, a mouse model of progeria. Mechanistically, progerin mislocalizes outside of the nucleus, interacts with the IGF-1R, and down-regulates its expression, leading to inhibited mitochondrial respiration, retarded cell growth, and accelerated cellular senescence. Pharmacological treatment with the PTEN (phosphatase and tensin homolog deleted on chromosome 10) inhibitor bpV (HOpic) increases Akt activity and improves multiple abnormalities in Zmpste24-deficient mice. These findings provide previously unidentified insights into the role of progerin in regulating the IGF-1R/Akt signaling in HGPS and might be useful for treating LMNA-associated progeroid disorders.

SNPs at SMG7 Associated with Time from Biochemical Recurrence to Prostate Cancer Death

BACKGROUND

A previous genome-wide association study identified several loci with genetic variants associated with prostate cancer survival time in two cohorts from Sweden. Whether these variants have an effect in other populations or if their effect is homogenous across the course of disease is unknown.

METHODS

These variants were genotyped in a cohort of 1,298 patients. Samples were linked with age, PSA level, Gleason score, cancer stage at surgery, and times from surgery to biochemical recurrence to death from prostate cancer. SNPs rs2702185 and rs73055188 were tested for association with prostate cancer-specific survival time using a multivariate Cox proportional hazard model. SNP rs2702185 was further tested for association with time to biochemical recurrence and time from biochemical recurrence to death with a multi-state model.

RESULTS

SNP rs2702185 at SMG7 was associated with prostate cancer-specific survival time, specifically the time from biochemical recurrence to prostate cancer death (HR, 2.5; 95% confidence interval, 1.4-4.5; P = 0.0014). Nine variants were in linkage disequilibrium (LD) with rs2702185; one, rs10737246, was found to be most likely to be functional based on LD patterns and overlap with open chromatin. Patterns of open chromatin and correlation with gene expression suggest that this SNP may affect expression of SMG7 in T cells.

CONCLUSIONS

The SNP rs2702185 at the SMG7 locus is associated with time from biochemical recurrence to prostate cancer death, and its LD partner rs10737246 is predicted to be functional.

IMPACT

These results suggest that future association studies of prostate cancer survival should consider various intervals over the course of disease.

Economic effects of command-and-control abatement policies under China's 2030 carbon emission goal

To mitigate greenhouse gas emissions, China has committed to reducing its national carbon emission intensity, which is a measure of carbon dioxide produced per unit of gross domestic product (GDP), by 65% by 2030 compared with the level in 2005. The government is pursuing corresponding abatement initiatives to achieve this goal. Coupling the physical data of sectoral energy inputs and emissions with a mixed exogenous/endogenous input-output model, this study first projected the carbon emissions in 2030 under a business-as-usual baseline and then investigated the potential economic effects of the "command-and-control" approach for reducing carbon emissions by limiting production capacity and strengthening forest carbon sink management. Three carbon abatement scenarios were evaluated from the perspectives of social equity, abatement efficiency, and forest carbon sinks. Our results indicated that, under the 2030 carbon emission goal, the GDP in China would decline by 17.17-41.26 trillion yuan (equivalent to a marginal abatement cost of 2315-5387 yuan per ton of carbon dioxide reduction), depending on different policy initiatives. The policy of carbon reduction for high-emission sectors only is more cost-effective and economically efficient and has resulted in fewer negative economic impacts than the policy of requiring all economic sectors to do so. Asking high-carbon emission industries to undertake carbon abatement can further reduce national carbon emission intensity. Additionally, promoting forest carbon sinks as an abatement initiative also demonstrates substantial economic benefits for society.

[Characteristics and changes of sensitization patterns of major allergens in children from 2010 to 2020 in a hospital of pediatric in Beijing]

Objective: To analyze the sensitization characteristics and change of major allergens in children from 2010 to 2020 in Beijing, so as to provide basis for diagnosis, treatment and prevention of allergic diseases in children. Methods: A retrospective study was conducted to analyze the children who were suspected of allergic diseases and tested for serum immunoglobulin E (total IgE and specific IgE) in the children's Hospital Affiliated to the Capital Institute of Pediatrics from January 2010 to December 2020. A total of 45 746 children aged 0-17 years in Beijing were enrolled with a median (interquartile range) of 3.8 (2.5, 5.3) years. There were 28 918 boys (63.2%) and 16 828 girls (36.8%) and 14 984 cases (32.8%) in the infant group (<3 years old), 22 049 cases (48.2%) in the preschool group (3-6 years old), and 8 713 cases (19.0%) in the school-age group (6 years old and above). Immunocap allergen detection system (fluorescence enzyme-linked immunosorbent assay) was used to detect and the characteristics and change trend of allergens during 11 years were statistically analyzed by Chi square test. Results: The top three positive rates of single food allergens sIgE were egg white 42.6% (2 788/6 577 tests), milk 38.4% (2 606/6 782 tests) and wheat 31.8% (1 417/4 449 tests), and the sequence of single inhaled allergens were Ragweed 42.6% (440/1 034 tests), Artemisia 38.4% (1 045/3 191 tests) and Alternaria alternata 31.3% (3 358/10 725 tests). The positive detection rates of egg white 47.0%(1 904/4 048 tests), milk 41.9%(1 769/4 226 tests) and wheat 33.9%(973/2 870 tests) in the infant group were the highest, and there have statistically significant(χ²=91.495, 73.907, 16.966, P<0.05). The positive rates of fx1 (22.5%, 121/537 tests), peanut (24.9%, 111/446 tests), soybean (20.0%, 74/370 tests) and shrimp (7.48%, 44/588 tests) were the highest in the school-age group(χ²=14.436, 10.751, 11.569, 13.703, P<0.05). The most common inhaled allergens were Alternaria alternata (14.8%, 422/2 859 tests) in the infant group, Ambrosia (34.5%, 143/415 tests) and Alternaria alternata (33.5%, 1 762/5 254 tests) in the preschool group, while in the school-age group were Ambrosia (56.4%, 282/500 tests) and Artemisia (48.2%, 573/1 189 tests). The positive rates of egg white, milk, wheat, sesame seed and peanut varied from 2010 to 2020, showing a trend of falling first and then rising(χ²=10.293,χ²=12.066,χ²=7.402,χ²=32.458,χ²=31.747,P<0.05).The positive detection rates of soybean showed a significant downward trend (21.4%, 173/809 tests in 2010, 15.4%, 70/455 tests in 2020, χ²=6.751,P=0.009), while that of shrimp and crab were at a stable low level(χ²=0.263, 1.346;P>0.05). From 2010 to 2020, mold (26.7%, 1 066/3 998 tests in 2010, 40.2% 1 705/4 243 tests in 2020), grass pollen (19.8%, 259/1 308 tests in 2010, 39.3%, 1 472/3 746 tests in 2020), tree pollen(17%, 180/1 058 tests in 2010, 29.8%, 916/3 075 tests in 2020) and animal dander (18.5%, 111/601 tests in 2010, 26.6%, 672/2 522 tests in 2020) were all showed significant upward trend (χ²=168.600, 163.601, 65.931 and 17.271 respectively, P<0.001) but dust mites (30.7%, 1 270/4 132 tests in 2010, 26.7%, 1 126/4 221 tests in 2020) showed a significant downward trend(χ²=16.822,P<0.001).In 2010, the most common inhaled allergen was dust mite 30.7% (1 270/4 132 tests), followed by mold 26.7% (1 066/3 998 tests), while they were mold 40.2% (1 705/1 243 tests), and grass pollen 39.3% (1 472/3 746 texts) respectively in 2020. Conclusion: In the past 11 years, the main food allergens in children were still egg white and milk, wheat, but the mold and pollen gradually replaced dust mite as the most common inhaled allergen.

A Class of Magnetic Topological Material Candidates with Hypervalent Bi Chains

The link between crystal and electronic structure is crucial for understanding structure-property relations in solid-state chemistry. In particular, it has been instrumental in understanding topological materials, where electrons behave differently than they would in conventional solids. Herein, we identify 1D Bi chains as a structural motif of interest for topological materials. We focus on Sm₃ZrBi₅, a new quasi-one-dimensional (1D) compound in the Ln₃MPn₅ (Ln = lanthanide; M = metal; Pn = pnictide) family that crystallizes in the P6₃/mcm space group. Density functional theory calculations indicate a complex, topologically nontrivial electronic structure that changes significantly in the presence of spin-orbit coupling. Magnetic measurements show a quasi-1D antiferromagnetic structure with two magnetic transitions at 11.7 and 10.7 K that are invariant to applied field up to 9 T, indicating magnetically frustrated spins. Heat capacity, electrical, and thermoelectric measurements support this claim and suggest complex scattering behavior in Sm₃ZrBi₅. This work highlights 1D chains as an unexplored structural motif for identifying topological materials, as well as the potential for rich physical phenomena in the Ln₃MPn₅ family.

[ALDH3B1 expression is correlated with histopathology and long-term prognosis of gastric cancer]

OBJECTIVE

To investigate the expression of aldehyde dehydrogenase 3B1 (ALDH3B1) in gastric cancer and explore its correlation with the pathological parameters and long-term prognosis of the patients.

METHODS

We analyzed the clinical data of 101 patients who underwent radical gastrectomy for gastric cancer in our hospital between January, 2013 and November, 2016, and examined the expression of ALDH3B1 in paraffin-embedded samples of gastric cancer tissues and adjacent tissues from these cases by immunohistochemical staining. We evaluated the correlation between ALDH3B1 expressions and histopathological parameters and assessed the predictive value of ALDH3B1 expression for long-term survival of the patients. We also examined the effect of lentivirus-mediated interference and overexpression of ALDH3B1 on the malignant behaviors of MGC-803 gastric cancer cells.

RESULTS

The expressions of ALDH3B1 and Ki67 were significantly higher in gastric cancer tissues than in adjacent tissues (P < 0.05). In gastric cancer patients, ALDH3B1 expression was positively correlated with peripheral blood CEA and CA19-9 levels (P < 0.01). The proportion of patients with CEA ≥5 μg/L, CA19-9 ≥37 kU/L, T stage of 3- 4, and N stage of 2-3 was significantly greater in high ALDH3B1 expression group than in low expression group. Kaplan-Meier survival analysis showed that the 5-year survival rate was significantly lower in gastric cancer patients with high ALDH3B1 expressions (P < 0.01). Univariate and Cox multiple regression analyses identified a high expression of ALDH3B1 (P < 0.05, HR= 0.231, 95% CI: 0.064-0.826), CEA≥5 μg/L (P < 0.01, HR=4.478, 95% CI: 1.530-13.110), CA19-9≥37 kU/L (P < 0.01, HR=3.877, 95% CI: 1.625-9.247), T stage of 3-4 (P < 0.01, HR=4.953, 95% CI: 1.768-13.880), and N stage of 2-3 (P < 0.05, HR=2.152, 95% CI: 1.152-4.022) as independent risk factors affecting 5-year survival after radical gastrectomy. The relative ALDH3B1 expression level, at the cut-off point of 4.66, showed a sensitivity of 76.47% and a specificity of 76% for predicting 5-year postoperative death (P < 0.01). In the cell experiment, overexpression of ALDH3B1 obviously promoted the proliferation, migration and invasion of MGC-803 cells.

CONCLUSION

As an independent risk factor affecting 5-year survival after radical gastrectomy, ALDH3B1 is highly expressed in gastric cancer and correlated with pathological parameters of the tumor, and a high ALDH3B1 expression may promote proliferation, invasion and metastasis of gastric cancer cells.

Moving MoO2/C Nanospheres with the Functions of Enrichment and Sensing for Online-High-Throughput SERS Detection

The development of online surface-enhanced Raman spectroscopy (SERS) detection methods is crucial to achieving high-throughput efficiency. Herein, a non-noble-metal moving substrate that integrates the functions of enrichment and sensing is developed for the microfluidic online-high-throughput detection of pollutants. The lowest limit of detection of 1 × 10^-12 M and a Raman enhancement factor of 6.3 × 10⁸ are obtained on the nanospheres. In a single detection channel, the analysis of 20 samples is achieved within 5 min, and the relative standard deviation of the signals is less than 6.8%. Compared with static SERS detection of fixed substrates, this dynamic SERS detection method greatly reduces the contamination memory effect of the analyte residue, enabling it to perform the sequential quantitative detection of samples with large concentration differences. Moreover, the current online SERS platform realizes the rapid quantitative detection of multicomponent samples.