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1.
Nucleic Acids Res ; 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33398349

RESUMO

RNA-guided nucleases (RGNs) based on CRISPR systems permit installing short and large edits within eukaryotic genomes. However, precise genome editing is often hindered due to nuclease off-target activities and the multiple-copy character of the vast majority of chromosomal sequences. Dual nicking RGNs and high-specificity RGNs both exhibit low off-target activities. Here, we report that high-specificity Cas9 nucleases are convertible into nicking Cas9D10A variants whose precision is superior to that of the commonly used Cas9D10A nickase. Dual nicking RGNs based on a selected group of these Cas9D10A variants can yield gene knockouts and gene knock-ins at frequencies similar to or higher than those achieved by their conventional counterparts. Moreover, high-specificity dual nicking RGNs are capable of distinguishing highly similar sequences by 'tiptoeing' over pre-existing single base-pair polymorphisms. Finally, high-specificity RNA-guided nicking complexes generally preserve genomic integrity, as demonstrated by unbiased genome-wide high-throughput sequencing assays. Thus, in addition to substantially enlarging the Cas9 nickase toolkit, we demonstrate the feasibility in expanding the range and precision of DNA knockout and knock-in procedures. The herein introduced tools and multi-tier high-specificity genome editing strategies might be particularly beneficial whenever predictability and/or safety of genetic manipulations are paramount.

2.
Support Care Cancer ; 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33398428

RESUMO

PURPOSE: Multiple myeloma (MM), a clonal plasma cell malignancy, composes around 10% of hematologic malignancies. Though recent advances in treatment have dramatically improved MM survival, some aggressive courses of disease and dismal outcomes still exist. Low body weight, undernutrition, and cachexia are noted at MM diagnosis. We aim to evaluate the impact of low body mass index (BMI) and undernutrition in MM patients. METHODS: We retrospectively analyzed MM patients at Taipei Veterans General Hospital in Taiwan between January 1, 2006 and October 31, 2018. Being underweight is defined as having a BMI of under 18.5 kg/m2. The patient's baseline characteristics, including BMI, serum albumin level, and comorbidities, etc., were recorded. The primary endpoint of the study was all-cause mortality. A Cox regression model was used to estimate the risk factors of mortality. RESULTS: A total of 378 newly diagnosed MM patients were enrolled in this study. The median age of the patients was 69. Thirty patients (7.9%) were underweight at diagnosis. The median overall survival was 1.3 years (95% CI 0.3-5.7) and 5.0 years (95% CI 3.1-5.9) for patients with low BMI and for patients with normal or higher BMI, respectively. In the multivariate analysis, low BMI (95% CI 1.07-4.44), ECOG ≥2 (95% CI 1.02-2.89), hypoalbuminemia (95% CI 1.21-4.01), high LDH (95% CI 1.22-3.49), and light chain ratio > 100 (95% CI 1.06-2.77) were independent risk factors of mortality. CONCLUSION: MM patients who were underweight, with hypoalbuminemia, poor performance status, higher LDH, and light chain ratio > 100 were associated with poor overall survival.

3.
Transgenic Res ; 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33400167

RESUMO

The releasing of transgenic soybeans (Glycine max (L.) Merr.) into farming systems raises concerns that transgenes might escape from the soybeans via pollen into their endemic wild relatives, the wild soybean (Glycine soja Sieb. et Zucc.). The fitness of F1 hybrids obtained from 10 wild soybean populations collected from China and transgenic glyphosate-resistant soybean was measured without weed competition, as well as one JLBC-1 F1 hybrid under weed competition. All crossed seeds emerged at a lower rate from 13.33-63.33%. Compared with those of their wild progenitors, most F1 hybrids were shorter, smaller, and with decreased aboveground dry biomass, pod number, and 100-seed weight. All F1 hybrids had lower pollen viability and filled seeds per plant. Finally, the composite fitness of nine F1 hybrids was significantly lower. One exceptional F1 hybrid was IMBT F1, in which the composite fitness was 1.28, which was similar to that of its wild progenitor due to the similarities in pod number, increased aboveground dry biomass, and 100-seed weight. Under weed competition, plant height, aboveground dry biomass, pod number per plant, filled seed number per plant, and 100-seed weight of JLBC-1 F1 were lower than those of the wild progenitor JLBC-1. JLBC-1 F1 hybrids produced 60 filled seeds per plant. Therefore, F1 hybrids could emerge and produce offspring. Thus, effective measures should be taken to prevent gene flow from transgenic soybean to wild soybean to avoid the production F1 hybrids when releasing transgenic soybean in fields in the future.

4.
In Vivo ; 35(1): 325-332, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33402481

RESUMO

BACKGROUND: Salvia miltiorrhiza is a medical herb for human disorders including cardiovascular diseases and cancer. However, the interactions between Salvia miltiorrhiza and its endophytes are largely unknown. The current study aimed at identifying its endophytic fungi and examining their inhibitory effects on anti-pathogenic fungus. MATERIALS AND METHODS: Distinct species of endophytic fungi were isolated from the roots of Salvia miltiorrhiza, cultured, sequenced, aiming to predict their taxonomical structures. Meanwhile, extracts from each endophytic fungus fermentations were isolated, compared and evaluated on the inhibitory efficacies on five pathological fungi, Cercospora nicotianae, Phoma arachnidicola, Staphylococcus, Phytophthora eggplant, and Rhizoctonia cerealis. RESULTS: A total of 34 strains of endophytic fungi were obtained from Salvia miltiorrhiza. Among them, SX19 and C. Gloeosporioids exhibited the most effective inhibitions on five pathogenic fungi. CONCLUSION: The anti-fungal activities of the endophytic fungus from Salvia miltiorrhiza were confirmed for the first time, and this may benefit crop quality and production in the future.

5.
Artigo em Inglês | MEDLINE | ID: mdl-33388869

RESUMO

INTRODUCTION: Intravertebral clefts (IVCs) typically occur in association with osteoporotic vertebral compression fractures (OVCFs) and can be characterized based on magnetic resonance imaging (MRI). This study aimed to identify the clinical characteristics of IVCs with different MRI signals and assess their influence on outcomes of vertebral augmentation. MATERIALS AND METHODS: We retrospectively recruited patients with OVCFs and associated IVCs who underwent vertebral augmentation. Patients were stratified into two groups based on whether the IVCs were full of liquid or gas, as determined by MRI signals. Patients were also stratified based on whether vertebral augmentation involved percutaneous kyphoplasty (PKP) or vertebroplasty (PVP). Pre- and postprocedural parameters were compared between groups. RESULTS: A total of 194 fractured vertebrae (86 liquid-filled, 108 gas-filled) were examined. Scores for bone cement distribution were significantly higher in the gas group than in the liquid group, indicating broader cement distribution in the gas group. In both groups, intervention significantly improved pain and mobility scores. Among patients with gas-filled IVCs, the incidence of bone cement leakage and recollapse of treated vertebrae were significantly higher after PKP than after PVP. In the liquid group, incidence of bone cement leakage and recollapse of treated vertebrae did not differ significantly between patients who received PKP or PVP. CONCLUSION: Vertebral augmentation is effective for treating OVCFs with gas- or liquid-filled IVCs. However, in patients with gas-filled IVCs, PKP may be associated with higher incidence of cement leakage and recollapse of treated vertebrae than PVP. Liquid-filled IVCs may not promote bone cement distribution.

6.
J Mol Histol ; 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33394292

RESUMO

Cav3.1, a subfamily of T-type calcium channel, is overexpressed in various human cancers and exerts important functions in tumor progression. This study is to identify the expression pattern and clinical significance of Cav3.1 in oral squamous cell carcinoma (OSCC). Firstly, the expression levels of Cav3.1 in oral mucosa (OM), dysplasia and oral squamous cell carcinoma (OSCC) were determined and compared by real-time quantitative PCR and Western blot analysis. After that, human tissue microarrays, containing 29 OM, 23 dysplasia and 122 primary OSCC samples, were applied to investigate the expression levels of Cav3.1, proliferation markers [Ki-67, proliferating cell nuclear antigen (PCNA)] and cellular anti-apoptosis markers [B cell lymphoma 2 (Bcl-2)] by immunohistochemistry and digital pathology analysis. In addition, we determined the function of Cav3.1 using knockdown assays of Cav3.1 in vitro. The results demonstrated that the mRNA and protein expression of Cav3.1 were significantly higher in OSCC specimens, and Cav3.1 expression in primary OSCCs was correlated with tumor size and pathological grade. Statistical analysis of immunohistochemical staining showed that Cav3.1 was closely correlated with Ki-67, PCNA and Bcl-2. Functional studies showed that the knockdown of Cav3.1 in OSCC cell lines using RNA interference influenced cell proliferation and apoptosis in vitro. Taken together, these findings suggested that Cav3.1 is overexpressed in OSCC tissues, also associated with proliferative and anti-apoptotic activity in oral squamous cell carcinoma.

7.
Artigo em Inglês | MEDLINE | ID: mdl-33410047

RESUMO

In this study, an approach for the facile, rapid, energy-saving, and sensitive determination of Fe3+ and Cr(VI) was developed. L-arginine/D-glucose carbon quantum dots (Arg/Glu-CQDs), with a photoluminescence quantum yield of 21%, were synthesized from L-arginine and D-glucose through a facile, hydrothermal process. The maximum emission wavelength of Arg/Glu-CQDs was observed at 450 nm, under an excitation wavelength of 365 nm. In addition, Arg/Glu-CQDs exhibited a sensitive and selective response to Fe3+ compared to Fe2+ and other metal ions. The Arg/Glu-CQDs' fluorescence was noticeably quenched through the inner filter effect (IFE) when Arg/Glu-CQDs were mixed with Fe3+. Accordingly, the Arg/Glu-CQDs/Fe2+ system could selectively detect Cr(VI); Cr(VI) could oxidize Fe2+ to Fe3+ and quench the fluorescence. The fluorescence sensor system (i.e., the Arg/Glu-CQDs/Fe2+ system) showed high sensitivity and excellent selectivity for the detection of Fe3+ and Cr(VI) in river water samples. Satisfactory detection efficiencies ranging from 97.07 to 103.46% were obtained. The cytotoxicity of Arg/Glu-CQDs was evaluated through an MTT assay using A549 cells as the target, to extend the application of Arg/Glu-CQDs to biological systems; the MTT assay indicated that the Arg/Glu-CQDs is non-cytotoxicity. Arg/Glu-CQDs were also successfully imaged in A549 cells indicating further application possibilities in bioimaging. Graphical abstract.

8.
J Bioinform Comput Biol ; : 2050047, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33410727

RESUMO

Non-negative Matrix Factorization (NMF) is a popular data dimension reduction method in recent years. The traditional NMF method has high sensitivity to data noise. In the paper, we propose a model called Sparse Robust Graph-regularized Non-negative Matrix Factorization based on Correntropy (SGNMFC). The maximized correntropy replaces the traditional minimized Euclidean distance to improve the robustness of the algorithm. Through the kernel function, correntropy can give less weight to outliers and noise in data but give greater weight to meaningful data. Meanwhile, the geometry structure of the high-dimensional data is completely preserved in the low-dimensional manifold through the graph regularization. Feature selection and sample clustering are commonly used methods for analyzing genes. Sparse constraints are applied to the loss function to reduce matrix complexity and analysis difficulty. Comparing the other five similar methods, the effectiveness of the SGNMFC model is proved by selection of differentially expressed genes and sample clustering experiments in three The Cancer Genome Atlas (TCGA) datasets.

9.
Brief Bioinform ; 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33415328

RESUMO

Triple-negative breast cancer (TNBC) has been a challenging breast cancer subtype for oncological therapy. Normally, it can be classified into different molecular subtypes. Accurate and stable classification of the six subtypes is essential for personalized treatment of TNBC. In this study, we proposed a new framework to distinguish the six subtypes of TNBC, and this is one of the handful studies that completed the classification based on mRNA and long noncoding RNA expression data. Particularly, we developed a gene selection approach named DGGA, which takes correlation information between genes into account in the process of measuring gene importance and then effectively removes redundant genes. A gene scoring approach that combined GeneRank scores with gene importance generated by deep neural network (DNN), taking inter-subtype discrimination and inner-gene correlations into account, was came up to improve gene selection performance. More importantly, we embedded a gene connectivity matrix in the DNN for sparse learning, which takes additional consideration with weight changes during training when obtaining the measurement of the relative importance of each gene. Finally, Genetic Algorithm was used to simulate the natural evolutionary process to search for the optimal subset of TNBC subtype classification. We validated the proposed method through cross-validation, and the results demonstrate that it can use fewer genes to obtain more accurate classification results. The implementation for the proposed method is available at https://github.com/RanSuLab/TNBC.

10.
BMC Cancer ; 21(1): 22, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33402129

RESUMO

BACKGROUND: An accurate intraoperative prediction of lymph node metastatic risk can help surgeons in choosing precise surgical procedures. We aimed to develop and validate nomograms to intraoperatively predict patterns of regional lymph node (LN) metastasis in patients with esophageal cancer. METHODS: The prediction model was developed in a training cohort consisting of 487 patients diagnosed with esophageal cancer who underwent esophagectomy with complete LN dissection from January 2016 to December 2016. Univariate and multivariable logistic regression were used to identify independent risk factors that were incorporated into a prediction model and used to construct a nomogram. Contrast-enhanced computed tomography reported LN status and was an important comparative factor of clinical usefulness in a validation cohort. Nomogram performance was assessed in terms of calibration, discrimination, and clinical usefulness. An independent validation cohort comprised 206 consecutive patients from January 2017 to December 2017. RESULTS: Univariate analysis and multivariable logistic regression revealed three independent predictors of metastatic regional LNs, three independent predictors of continuous regional LNs, and two independent predictors of skipping regional LNs. Independent predictors were used to build three individualized prediction nomograms. The models showed good calibration and discrimination, with area under the curve (AUC) values of 0.737, 0.738, and 0.707. Application of the nomogram in the validation cohort yielded good calibration and discrimination, with AUC values of 0.728, 0.668, and 0.657. Decision curve analysis demonstrated that the three nomograms were clinically useful in the validation cohort. CONCLUSION: This study presents three nomograms that incorporate clinicopathologic factors, which can be used to facilitate the intraoperative prediction of metastatic regional LN patterns in patients with esophageal cancer.

11.
Nat Nanotechnol ; 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33432207

RESUMO

Photons that have a helical phase front, that is, twisted photons, can carry a discrete, in principle, unlimited, but quantized amount of orbital angular momentum (OAM). Hence, twisted single photons constitute a high-dimensional quantum system with information-processing abilities beyond those of two-level single-photon qubits. To date, the generation of single photons carrying OAM has relied on a non-linear process in bulk crystals, for example, spontaneous parametric down-conversion, which limits both the efficiency and the scalability of the source. Here, we present a bright solid-state source of single photons in an OAM superposition state with a single-photon purity of g(2)(0) = 0.115(1) and a collection efficiency of 23(4)%. The mode purity of the single-photon OAM states is further examined via projection measurements. Future developments of integrated quantum photonic devices with pure OAM states as an additional degree of freedom may enable high-dimensional quantum information processing.

12.
AMB Express ; 11(1): 18, 2021 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-33433783

RESUMO

Microbial degradation of recalcitrant alkanes under anaerobic conditions results in the accumulation of heavy oil fraction in oil reservoirs. Hydroxylation of alkanes is an important activation mechanism under anaerobic conditions, but the diversity and distribution of the responsible microorganisms in the subsurface environment are still unclear. The lack of functional gene polymerase chain reaction (PCR) primers and commercially available intermediate degradation chemical compounds are the major obstacles for this research. In this investigation, PCR primers for the ahyA gene (encoding alkane hydroxylase) were designed, evaluated, and improved based on the nucleotide sequences available. Using microbial genomic DNA extracted from oil-contaminated soil and production water samples of oil reservoirs, ahyA gene nucleotide sequences were amplified and retrieved successfully from production water sample Z3-25 of Shengli oilfield. Additionally, the signature biomarker of 2-acetylalkanoic acid was detected in both Shengli and Jiangsu oilfields. These results demonstrate that anaerobic hydroxylation is an active mechanism used by microorganisms to degrade alkanes in oxygen-depleted oil reservoirs. This finding expands the current knowledge of biochemical reactions about alkane degradation in subsurface ecosystems. In addition, the PCR primers designed and tested in this study serve as an effective molecular tool for detecting the microorganisms responsible for anaerobic hydroxylation of alkanes in this and other ecosystems.

13.
J Neurointerv Surg ; 2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33468608

RESUMO

BACKGROUND: It is unclear whether the sandwich vertebra, is at higher risk of new symptomatic fractures (NSFs), and whether prophylactic augmentation might benefit patients with sandwich vertebrae. OBJECTIVE: To compare fracture-free probabilities of sandwich, ordinary-adjacent, and non-adjacent vertebrae, and identify predictors of NSFs. METHODS: Data were retrospectively analyzed for patients who had undergone vertebral augmentation resulting in sandwich vertebrae. NSF rates were determined and predictors were identified using Cox proportional hazard models. RESULTS: The analysis included 1408 untreated vertebrae (147 sandwich, 307 ordinary-adjacent, 954 non-adjacent vertebrae) in 125 patients. NSFs involved 19 sandwich, 19 ordinary-adjacent, and 16 non-adjacent vertebrae. The NSF rate was significantly higher in the patients with sandwich vertebrae (27.2%) than among all patients (14.8%). At the vertebra-specific level, the NSFs rate was 12.9% for sandwich vertebrae, significantly higher than 6.2% for ordinary-adjacent and 1.7% for non-adjacent vertebrae. The corresponding fracture-free probabilities of sandwich, ordinary-adjacent, and non-adjacent vertebrae were 0.89, 0.95, and 0.99 at 1 year, and 0.85, 0.92, and 0.98 at 5 years (p<0.05). Cox modeling identified the following as predictors for occurrence of an NSF in a given vertebra: vertebra location, type of vertebrae, number of augmented vertebrae, and puncture method. CONCLUSION: Sandwich vertebrae are at higher risk of NSFs than ordinary-adjacent and non-adjacent vertebrae, and several NSF risk factors were identified. Since 85% of sandwich vertebrae are fracture-free for 5 years and NSF risk increases with the number of augmented vertebrae, prophylactic augmentation of every sandwich vertebra may be unnecessary.

14.
Environ Health Prev Med ; 26(1): 2, 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33397280

RESUMO

OBJECTIVES: We performed an updated meta-analysis to clarify the relationship between the CEBPE rs2239633 polymorphism and the childhood acute lymphoblastic leukemia (CALL) susceptibility. METHODS: All the case-control studies were updated on October 5, 2020, through Web of Science, PubMed, Cochrane Library, Embase, and China National Knowledge Infrastructure (CNKI) electronic database. The heterogeneity in the study was tested by the Q test and I2, and then the random ratio or fixed effect was utilized to merge the odds ratios (OR) and 95% confidence interval (CI). We also performed sensitivity analysis to estimate the impact of individual studies on aggregate estimates. Publication bias was investigated by using funnel plot and Egger's regression test. All statistical analyses were performed using Stata 12.0. RESULTS: A total of 20 case-control studies were selected, including 7014 patients and 16,428 controls. There was no association of CEBPE rs2239633 polymorphism with CALL (CC vs CT + TT: OR = 1.08, 95% CI = 0.94-1.26; CC + CT vs TT: OR = 1.10, 95% CI = 0.94-1.30; C vs T: OR = 1.02, 95% CI = 0.92-1.13). In the subgroup analysis by ethnicity, there is no significant association of this polymorphism and CALL risks among Asian and Caucasian populations in the three genetic models (CC vs CT + TT, CC + CT vs TT, and C vs T). CONCLUSION: This meta-analysis found no significant association between the CEBPE rs2239633 polymorphism and susceptibility to CALL.

15.
Br J Pharmacol ; 2021 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-33443775

RESUMO

BACKGROUND AND PURPOSE: Colorectal cancer (CRC) is the third most common cancer worldwide. HER2 and HER3 are two members of human epidermal receptor family of tyrosine kinase receptors (RTKs) and associated with poor survival in CRC. They have been observed as important therapeutic targets in various types of cancer. Corosolic acid (CRA), a natural pentacyclic triterpene has been demonstrated to have significant anticancer activity. However, the target of CRA has not yet been explored. This study aimed to reveal the direct targets of CRA underlying its anticancer activities. EXPERIMENTAL APPROACH: The targets of CRA were revealed by the phospho-RTK array, Bio-layer interferometry, co-immunoprecipitation and Proximity ligation assay. The inhibitory action of CRA on HER2/HER3 heterodimerization and related downstream signaling were investigated in HCT116 and SW480 cells. In addition, the chemopreventive effects of CRA were validated in both HCT116 xenograft model and AOM/DSS model. KEY RESULTS: Our results demonstrated that CRA could prevent NRG1-induced HER2/HER3 heterodimerization and suppress the phosphorylation of both HER2 and HER3. Furthermore, HER2 and HER3 could regulate the downstream signaling pathways of RalA/RalBP1/CDK1 and PI3K/Akt/PKA respectively, resulting in the changes in phosphorylation of Drp1 and mitochondrial dynamics. CRA exhibited anticancer activity in both HCT116 xenograft model and AOM/DSS model. CONCLUSIONS AND IMPLICATIONS: Collectively, our results demonstrated CRA directly targeted HER2 and HER3 heterodimerization and inhibited mitochondrial fission via regulating RalA/RalBP1/CDK1 and PI3K/Akt/PKA pathways, revealing a novel mechanism underlying the beneficial effects of CRA on CRC.

16.
Drug Des Devel Ther ; 15: 195-207, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33469271

RESUMO

Local anesthetics have the advantage of complete analgesia with fewer side effects compared to systemic analgesics. However, their clinical use is limited due to their short duration of action. Thus, local anesthetics with fast onset, long duration of action, selective nociceptive block, and low local and systemic toxicity are highly desirable. In the past electrophysiological studies, quaternary lidocaine derivatives (QLDs) showed these characteristics. Here, we review electrophysiological properties of QLDs and their pharmacodynamic characteristics to shed light on potential problems.

17.
Biosens Bioelectron ; 177: 112976, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33434778

RESUMO

DNA molecular probes have emerged as powerful tools for fluorescence imaging of microRNAs (miRNAs) in living cells and thus elucidating functions and dynamics of miRNAs. In particular, the highly integrated DNA probes that can be able to address the robustness, sensitivity and consistency issues in a single assay system were highly desired but remained largely unsolved challenge. Herein, we reported for the first time that the development of the novel DNA nanomachines that split-DNAzyme motif was highly integrated in a single DNA triangular prism (DTP) reactor and can undergo target-activated DNAzyme catalytic cascade circuits, allowing amplified sensing and imaging of tumor-related microRNA-21 (miR-21) in living cells. The DNA nanomachines have shown dynamic responses for target miR-21 with excellent sensitivity and selectivity and demonstrated the potential for living cell imaging of miR-21. With the advantages of facile modular design and assembly, high biostability, low cytotoxicity and excellent cellular internalization, the highly integrated DNA nanomachines enabled accurate and effective monitoring of miR-21 expression levels in living cells. Therefore, our developed strategy may afford a reliable and robust nanoplatform for tumor diagnosis and for related biological research.

18.
J Inorg Biochem ; 216: 111354, 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33454609

RESUMO

Multifunctional drugs with synergistic effects have been widely developed to enhance the treatment efficiency of various diseases, such as malignant tumors. Herein, a novel bifunctional manganese(I)-based prodrug [MnBr(CO)3(APIPB)] (APIPB = N-(2-aminophen-yl)-4-(1H-imidazo[4,5-f] [1, 10] phenanthrolin-2-yl)benzamide) with inhibitory histone deacetylase (HDAC) activity and light-controlled carbon monoxide (CO) delivery was successfully designed and synthesized. [MnBr(CO)3(APIPB)] readily released CO under visible light irradiation (λ > 400 nm) through which the amount of released CO could be controlled by manipulating light power density and illumination time. In the absence of light irradiation, the cytotoxic effect of [MnBr(CO)3(APIPB)] on cancer cells was greater than that of the commercially available HDAC inhibitor MS-275. Consequently, with a combination of CO delivery and HDAC inhibitory activity, [MnBr(CO)3(APIPB)] showed a remarkably enhanced antitumor effect on HeLa cells (IC50 = 3.2 µM) under visible light irradiation. Therefore, this approach shows potential for the development of medicinal metal complexes for combined antitumor therapies.

19.
Ying Yong Sheng Tai Xue Bao ; 32(1): 103-112, 2021 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-33477218

RESUMO

Syzygium album is a plant species with extremely small population and endemic to Yun-xiao County, Fujian Province. We examined its population status and conservation evaluation. The results showed that there were 25 individuals of S. album, with only one mother tree. Except for the mother tree and one small tree, the others were all young seedlings, which was rare in abundance and lack of age stage of middle and strong trees. The spatial distribution of young seedlings was not uniform, with most of individuals within the range of 10-25 m from the mother tree. The age class structure of the population was not continuous and the population development was unsustainable. The competition mainly came from other species. Cryptocarya chinensis accounted for 66.6% of the total competition index, which was much higher than other species. We established a comprehensive evaluation index system for the protection of rare and endangered plants with extremely small populations and evaluated the protection of S. album from three aspects, i.e., endangered degree, protection value, and protection priority. The endangered degree of S. album was level Ⅰ (the endangered degree index was 4.510), belonging to extremely endangered species, the protection value was level Ⅰ (the protection value index was 4.052), which was of great value, and the protection priority was level Ⅰ (the protection priority index was 4.016), which should be listed as the highest priority protection level.

20.
Phys Chem Chem Phys ; 2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33458726

RESUMO

In this work, combining first-principles calculations with kinetic Monte Carlo (KMC) simulations, we constructed an irregular carbon bridge on the graphene surface and explored the process of H migration from the Pt catalyst to carbon bridge, and further migration to the graphene surface. The calculated reaction diagrams show that the hydrogen atoms can easily migrate from the Pt cluster to the carbon bridge with a low barrier of 0.22-0.86 eV, and KMC simulations indicate that the migration reactions can take place at intermediate temperatures (91.9-329.5 K). Our research clarified the role of the carbon bridge: (1) the close combination of Pt clusters and carbon bridges reduces H2 adsorption enthalpy, which facilitates the spillover of H atoms from the Pt cluster to the carbon bridges and (2) the unsaturated carbon atoms on the carbon bridges have radical character and tend to bind radical H atoms. The subsequent study shows that the F atoms decorated on graphene can greatly reduce the migration barrier of H atoms from the carbon bridge to graphene. With F atoms decorated, the carbon atoms are in an electron-deficient state, which have a strong ability to bind the hydrogen atoms, and it promotes the migration of H atoms to the graphene surface. The migration barrier and reaction temperature are reduced to 0.72 eV and 279 K, respectively.

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