Surface-supported isolated atoms in single-atom catalysts (SACs) are usually stabilized by diverse defects. The fabrication of high-metal-loading and thermally stable SACs remains a formidable ...challenge due to the difficulty of creating high densities of underpinning stable defects. Here we report that isolated Pt atoms can be stabilized through a strong covalent metal-support interaction (CMSI) that is not associated with support defects, yielding a high-loading and thermally stable SAC by trapping either the already deposited Pt atoms or the PtO
units vaporized from nanoparticles during high-temperature calcination. Experimental and computational modeling studies reveal that iron oxide reducibility is crucial to anchor isolated Pt atoms. The resulting high concentrations of single atoms enable specific activities far exceeding those of conventional nanoparticle catalysts. This non defect-stabilization strategy can be extended to non-reducible supports by simply doping with iron oxide, thus paving a new way for constructing high-loading SACs for diverse industrially important catalytic reactions.
Abstract
The interfacial sites of supported metal catalysts are often critical in determining their performance. Single-atom catalysts (SACs), with every atom contacted to the support, can maximize ...the number of interfacial sites. However, it is still an open question whether the single-atom sites possess similar catalytic properties to those of the interfacial sites of nanocatalysts. Herein, we report an active-site dependent catalytic performance on supported gold single atoms and nanoparticles (NPs), where CO oxidation on the single-atom sites is dramatically promoted by the presence of H
2
O whereas on NPs’ interfacial sites the promoting effect is much weaker. The remarkable H
2
O promoting effect makes the Au SAC two orders of magnitude more active than the commercial three-way catalyst. Theoretical studies reveal that the dramatic promoting effect of water on SACs originates from their unique local atomic structure and electronic properties that facilitate an efficient reaction channel of CO + OH.
The regulation of iron (Fe) homeostasis is critical for plant survival. Although the systems responsible for the reduction, uptake, and translocation of Fe have been described, the molecular ...mechanism by which plants sense Fe status and coordinate the expression of Fe deficiency-responsive genes is largely unknown. Here, we report that two basic helix-loop-helix-type transcription factors, bHLH34 and bHLH104, positively regulate Fe homeostasis in Arabidopsis (Arabidopsis thaliana). Loss of function of bHLH34 and bHLH104 causes disruption of the Fe deficiency response and the reduction of Fe content, whereas overexpression plants constitutively promote the expression of Fe deficiency-responsive genes and Fe accumulation. Further analysis indicates that bHLH34 and bHLH104 directly activate the transcription of the Ib subgroup bHLH genes, bHLH38/39/100/101. Moreover, overexpression of bHLH101 partially rescues the Fe deficiency phenotypes of bhlh34bhlh104 double mutants. Further investigation suggests that bHLH34, bHLH104, and bHLH105 (IAA-LEUCINE RESISTANT3) function as homodimers or heterodimers to nonredundantly regulate Fe homeostasis. This work reveals that plants have evolved complex molecular mechanisms to regulate Fe deficiency response genes to adapt to Fe deficiency conditions.
Iron (Fe) deficiency is a limiting factor for the normal growth and development of plants, and many species have evolved sophisticated systems for adaptation to Fe-deficient environments. It is still ...unclear how plants sense Fe status and coordinate the expression of genes responsive to Fe deficiency. In this study, we show that the bHLH transcription factor bHLH115 is a positive regulator of the Fe-deficiency response. Loss-of-function of bHLH115 causes strong Fe-deficiency symptoms and alleviates expression of genes responsive to Fe deficiency, whereas its overexpression causes the opposite effect. Chromatin immunoprecipitation assays confirmed that bHLH115 binds to the promoters of the Fe-deficiency-responsive genes bHLH38/39/100/101 and POPEYE (PYE), which suggests redundant molecular functions with bHLH34, bHLH104, and bHLH105. This is further supported by the fact that the bhlh115-1 mutant was complemented by overexpression of any of bHLH34, bHLH104, bHLH105, and bHLH115. Further investigations determined that bHLH115 could interact with itself and with bHLH34, bHLH104, and bHLH105. Their differential tissue-specific expression patterns and the severe Fe deficiency symptoms of multiple mutants supported their non-redundant biological functions. Genetic analysis revealed that bHLH115 is negatively regulated by BRUTUS (BTS), an E3 ligase that can interact with bHLH115. Thus, bHLH115 plays key roles in the maintenance of Fe homeostasis in Arabidopsis thaliana.
Major outbreaks of influenza virus occurred in China in 2017-2018. To describe the pattern of influenza circulation and timing of seasonal epidemics, we analyzed data from influenza-like illness ...(ILI) specimens on surveillance wards of sentinel hospitals during 2014-2018. Among 1,890,084 ILI cases, 324,211 (17.2%) tested positive for influenza. Influenza A virus (particularly A/H3N2), which circulates annually, was detected in 62% of cases, compared with influenza B virus in 38% of cases. The detection rate of A/H1N1, A/H3N2, B/Victoria, and B/Yamagata viruses were 3.56%, 7.07%, 2.08%, and 3.45%, respectively. Influenza prevalence was generally stable over the four years analyzed, but obvious outbreaks occurred in 2015-2016 (17.28%) and 2017-2018 (22.67%), with B/Victoria and B/Yamagata contributing to these outbreaks, respectively. In the south, a characteristic peak in infections was detected in the summer (week 23-38), which was not detected in the north. Influenza B was found high frequency in school-age children (5-14 years) with 4.78% of B/Victoria and 6.76% of B/Yamagata. Therefore, the epidemiological characteristics of seasonal influenza were complex in China during 2014-2018, presenting distinctions in region, season, and susceptible population. These findings underline the importance of enhancing year-round influenza surveillance and provide a reference for the timing and variety of influenza vaccination.
Cytochrome P450 26A1 (CYP26A1) plays important roles in the mice peri‐implantation period. Inhibiting its expression or function leads to pregnancy failure. However, little is known about the ...underlying mechanisms involved, especially the relationship between CYP26A1 and immune cells. In this study, using Cyp26a1‐specific antisense morpholigos (Cyp26a1‐MO) knockdown mice model and pCR3.1‐Cyp26a1 vaccine mice model, we found that the number of uterine CD45+CD11c+MHCIIlo‐hiF4/80− dendritic cells (DCs) was significantly decreased in the treated mice. The percentage of mature DCs (CD86hi) was obviously lower and the percentage of immature DCs (CD86lo) was remarkably higher in uterine DCs in the treatment group than that of the control group. Further experiments found that ID2, a transcription factor associated with DCs development, and CD86, a DC mature marker molecule, were both significantly reduced in mice uteri in the treated group. In vitro, ID2 and CD86 also decreased in bone marrow‐derived DCs under Cyp26a1‐MO treatment. These findings provide novel information that CYP26A1 might affect the embryo implantation via modulating the differentiation and maturation of uterine DCs.
Background
IBM Watson for Oncology (WFO), which can use natural language processing to evaluate data in structured and unstructured formats, has begun to be used in China. It provides physicians with ...evidence‐based treatment options and ranks them in three categories for treatment decision support. This study was designed to examine the concordance between the treatment recommendation proposed by WFO and actual clinical decisions by oncologists in our cancer center, which would reflect the differences of cancer treatment between China and the U.S.
Patients and Methods
Retrospective data from 362 patients with cancer were ingested into WFO from April 2017 to October 2017. WFO recommendations were provided in three categories: recommended, for consideration, and not recommended. Concordance was analyzed by comparing the treatment decisions proposed by WFO with those of the multidisciplinary tumor board. Concordance was achieved when the oncologists' treatment decisions were in the recommended or for consideration categories in WFO.
Results
Ovarian cancer showed the highest concordance, which was 96%. Lung cancer and breast cancer obtained a concordance of slightly above 80%. The concordance of rectal cancer was 74%, whereas colon cancer and cervical cancer showed the same concordance of 64%. In particular, the concordance of gastric cancer was very low, only 12%, and 88% of cases were under physicians choice.
Conclusion
Different cancer types showed different concordances, and only gastric cancers were significantly less likely to be concordant. Incidence and pharmaceuticals may be the major cause of discordance. To be comprehensively and rapidly applied in China, WFO needs to accelerate localization. ClinicalTrials.gov Identifier: NCT03400514.
Implications for Practice
IBM Watson for Oncology (WFO) has begun to be used in China. In this study, concordance was examined between the treatment recommendation proposed by WFO and clinical decisions for 362 patients in our cancer center, which could reflect the differences of cancer treatment between China and the U.S. Different cancer types showed different concordances, and only gastric cancers were significantly less likely to be concordant. Incidence and pharmaceuticals may be the major causes of discordance. To be comprehensively and rapidly applied in China, WFO needs to accelerate localization. This study may have a significant effect on application of artificial intelligence systems in China.
摘要
背景。IBM 沃森肿瘤 (WFO) 可以使用自然语言处理程序来评估结构化和非结构化格式的数据，我们已在中国开展使用。它可以提供各种基于证据的治疗选择并将它们划分为三个类别，以提供治疗决策支持。本研究旨在检验 WFO 提出的治疗建议与我们癌症中心的肿瘤医生制定的实际临床决策之间的一致性，这可以反映出中美之间的癌症治疗差异。
患者和方法。在 2017 年 4 月至 2017 年 10 月期间，WFO 输入了来自 362 名癌症患者的回顾性数据。按照三种类别提供 WFO 建议:建议、以供考虑和不建议。通过对比 WFO 与多学科肿瘤委员会建议的治疗决策，我们对一致性进行了分析。当肿瘤医生的治疗决策在 WFO 中属于建议或以供考虑的类别时，即表示实现了一致性。
结果。卵巢癌显示出最高的一致性，为 96%。肺癌和乳腺癌取得了略高于 80% 的一致性。直肠癌的一致性为 74%，而结肠癌和宫颈癌显示出相同的一致性，同为 64%。特别值得注意的是，胃癌的一致性非常低，仅为 12%，88% 的病例均由医生选择。
结论。不同的癌症类型显示出不同的一致性，只有胃癌明显不太可能一致。发病率和药物可能是导致不一致的主要原因。为了实现在中国的全面、快速应用，WFO 需要加速本地化。ClinicalTrials.gov 标识符:NCT03400514。
对临床实践的提示:我们现已在中国开始使用 IBM 沃森肿瘤 (WFO)。在本研究中，我们检验了针对我们癌症中心的 362 名患者的 WFO 治疗建议与临床决策之间的一致性，这可以反映出中美之间的癌症治疗差异。不同的癌症类型显示出不同的一致性，只有胃癌明显不太可能一致。发病率和药物可能是导致不一致的主要原因。为了实现在中国的全面、快速应用，WFO 需要加速本地化。本研究可能对人工智能系统在中国的应用产生重大影响。
Using the updated version of IBM Watson for Oncology, this study explored the concordance of the suggested therapeutic regimen between Watson and physicians in China. This article reports results and suggests some similarities and differences between the East and West in the treatment of cancer.
Chirality is a fundamental property of nature. Separation and analysis of racemates are of great importance in the fields of medicine and the production of chiral biopharmaceutical intermediates. ...Chiral chromatography has the characteristics of a wide separation range, fast separation speed, and high efficiency. The development and preparation of novel chiral stationary phases with good chiral recognition and separation capacity is the core and key of chiral chromatographic separation and analysis. In this work, the representative research progress of novel chiral porous crystal materials including chiral covalent organic frameworks, chiral porous organic cages, chiral metal‐organic frameworks, and chiral metal‐organic cages used as chiral stationary phases of capillary gas chromatography and high‐performance liquid chromatography over the last 4 years is reviewed in detail. The chiral recognition and separation properties of the representative studies in this review are also introduced and discussed.
•The fluorescent probes, chemiluminescent probes and bioluminescent probes for sensing NTRs were reviewed.•The design strategies of those modes were discussed based on different probes.•The ...advantages and drawbacks of those detection modes were discussed.•A prospect for the detection of NTRs activity was proposed.
As one of the most representative hypoxic enzymes, nitroreductases (NTRs) play momentous roles in malignant tumor progression, metastasis, invasion and angiogenesis. They are also a key hallmark of highly aggressive disease in various hypoxic tumor cells. In addition, NTRs participate in essential processes of detoxification, pro-drug activation as well as radiation therapy. Thus, the detection of NTRs has great importance for theranostic and drug development. In this review, we focused on the design principles, sensing mechanisms and biological applications of small-molecule probes for NTRs detection over the past ten years (2010–2020). We also highlighted the challenges and future directions in this rapidly developing field. Significantly, we hope that some insights and inspiration for future research work will be provided to surmount the Achilles’ Heels of the small-molecule probes, such as limited application, for detecting NTRs.
Pueraria lobata is a typical medicinal and edible plant with great market value and demand, thus exploring the relationship between soil environmental factors and the yield and quality of Pueraria ...lobata is of great significance for its high-value cultivation. In this study, using the Guige 1 variety (Pueraria montana var. Thomsonii) selected by our research group as the material to compare the effects of five soil types, endophytes in three parts of Pueraria lobata and two fertilizers on its yield and quality. The results showed that the comprehensive evaluation effect of five soil types on the yield and quality of Guige 1 was as follow: red-yellow mixed soil (RYMS) > black loam soil (BLS) > sandy loam soil (SLS) > sandy loam soil waterlogging (SLSW) > yellow soil compaction soil (YSCS); the descending order of endophyte types and quantities is in BLS > RYMS > SLS > YSC > SLSW; applying General Compound Fertilizers (GCF) in RYMS is more suitable for the rapid expansion of Guige 1 than Organic-Slow-Release-Fertilizers (OSRF). The high potassium content in RYMS and high effective phosphorus content in BLS are positively correlated with the content of starch and isoflavone in Pueraria lobata. The conclusion is that the high potassium and available phosphorus content in RYMS and BLS, as well as the rich types and quantities of endophytic bacteria, are positively correlated with the yield and quality of Pueraria lobata. The research results have important guiding significance for the high-value cultivation of Pueraria lobata.
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