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As the magic methyl effect is well acknowledged in pharmaceutical molecules, the development of simple and efficient methods for the installment of methyl groups on complex molecules is highly coveted. Hence, we provide a general strategy for radical cascade cyclization of N-(o-cyanobiaryl)acrylamides by utilizing sulfonium salts as the sources of methyl radical and merging photoredox and copper catalysis. This novel protocol can access a wide variety of methylation or remote thioether-substituted benzo-fused N-heterocycle derivatives, which can be easily transformed into diverse highly valuable sulfone and sulfoximine compounds via late-stage diversification. Moreover, to further demonstrate the synthetic utility of this conversion, the methyl(phenyl)sulfide, which serves as both raw material and byproduct, can be recovered and reused in this transformation. The scale-up experiment for the one-pot two-step process directly offers the target product in good yield under the standard conditions.

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A visible-light-mediated radical cascade cyclization of N-(o-cyanobiaryl)acrylamides with oxime esters for the assembly of acyl-containing pyrido[4,3,2-gh]phenanthridines has been developed. The present protocol tolerates a wide range of oxime esters through a single reaction via fragmentation, radical addition, nitrile insertion, and cyclization under mild conditions.

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An efficient and operationally simple oxidative radical difunctionalization of N-aryl bicyclobutyl (BCB) amides with aldehydes is described. It was found that acylated 3-spirocyclobutyl oxindoles were generated from the coupling of BCB-amides and aromatic aldehydes, while reactions gave exclusively decarbonylative alkylarylation products using alkyl aldehydes as radical precursors.

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A novel strategy for the difunctionalization of electron-deficient alkenes with aryl sulfonium salts to access remote sulfur-containing oxindole derivatives by using in situ-formed copper(I)-based complexes as a photoredox catalyst is presented. This method enables the generation of the C(sp3)-centered radicals through site selective cleavage of the C-S bond of aryl sulfonium salts under mild conditions. Moreover, the oxidation reactions of desired products provide a new strategy for the preparation of sulfoxide or sulfone-containing compounds. Importantly, this approach can be easily applied to late-stage modification of pharmaceuticals molecules.

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2-Aminobenzothiazoles are commonly encountered in various functional compounds. Herein, we disclose an electro-oxidative three-component reaction for the effective synthesis of 2-aminobenzothiazoles under mild conditions, utilizing non-toxic and abundant elemental sulfur as the sulfur source. Both aliphatic amines and aryl amines demonstrate good compatibility at room temperature, highlighting the broad functional group tolerance of this approach. Additionally, elemental selenium demonstrated reactivities comparable to those of elemental sulfur.

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A visible-light-induced radical alkylarylation of N-aryl bicyclobutyl amides with α-carbonyl alkyl bromides for the synthesis of functionalized 3-spirocyclobutyl oxindoles is described in which ß-selective radical addition of the alkyl radical to N-aryl bicyclobutyl amides forms a key radical intermediate followed by interception with intrinsic arene functional group. This approach can be applicable to a wide range of α-carbonyl alkyl bromides, including primary, secondary, and tertiary α-bromoalkyl esters, ketones, nitriles, and nitro compounds.

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In the epoch of the digital economy, technological innovation and energy conservation are significantly facilitated by digital infrastructure, leading to substantial improvements in green innovation efficiency at the provincial level. This study employed the feasible generalized least square (FGLS) method to examine the effects of digital infrastructure on the green innovation efficiency across 30 provinces in the Chinese mainland, utilizing panel data from 2011 to 2020. Additionally, this investigation delves into the intervening role of industrial structure upgrading and the amplifying effects of environmental regulation and human capital on the process. Findings indicate that, to begin with, digital infrastructure contributes to the meaningful enhancement of green innovation efficiency within provinces. Subsequently, the industrial structure upgrading partially mediates the impact of digital infrastructure on the efficiency of provincial green innovation. Lastly, both human capital and environmental regulations amplify the beneficial influence of digital infrastructure on the effectiveness of green innovation at the provincial level. This study provides valuable insights into the mechanisms through which digital infrastructure boosts green innovation efficiency, aiding policymakers in formulating appropriate policies to augment digital infrastructure, thereby promoting provincial green innovation efficiency.

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Cyclobutanone oximes and their derivatives are pivotal core structural motifs in organic chemistry. Iminyl-radical-triggered C-C bond cleavage of cyclobutanone oximes delivers an efficient strategy to produce stable distal cyano-substituted alkyl radicals, which can capture SO2, CO or O2 to form cyanoalkylsulfonyl radicals, cyanoalkylcarbonyl radicals or cyanoalkoxyl radicals under mild conditions. In the past several years, cyanoalkylsulfonylation/cyanoalkylcarbonyaltion/cyanoalkoxylation has attracted a lot of interest. In this updated report, the strategies for trapping SO2, CO or O2via iminyl-radical-triggered ring-opening of cyclobutanone oximes are summarized.

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Background: The function of Chromobox 4 (CBX4) function has attracted attention in many cancer types due to its unique biological role; however, its mechanism in esophageal squamous cell carcinoma (ESCC) under radiotherapeutic treatment has not yet been investigated. Methods: Silencing of CBX4 was carried out in TE-13 and KYSE-150 cell lines. Cell proliferation, radiosensitivity, DNA damage, apoptosis, and cell cycle distribution were determined by Cell Counting Kit-8 (CCK-8), colony formation assay, immunofluorescence, flow cytometry, and immunoblot in vitro. In vivo xenograft models were also used to assess tumor cell growth and radioresistance. The underpinning mechanisms were explored based on pathway analysis and confirmed by rescue experiments, detecting cellular autophagy. Results: Knockdown of CBX4 resulted in reduced tumor growth and enhanced radio-response in vivo and in vitro. Down-regulating CBX4 increased DNA damage, apoptotic rate, and G2/M arrest induced by radiation in ESCC cell lines. Gene Set Enrichment Analysis (GSEA) revealed that CBX4 was associated with cellular autophagy regulation. Enhanced radiosensitivity in ESCC cells silenced for CBX4 was partially blocked by autophagy inhibition (P<0.05). Beclin 1 was upregulated at the gene and protein levels in ESCC cells with CBX4 knockdown after irradiation, and overexpressing Beclin 1 reversed the radiosensitivity of ESCC cells with CBX4 knockdown (P<0.05). Conclusions: By regulating autophagic activity, CBX4 contributes to radioresistance. Targeting CBX4 might constitute an efficient approach for increasing radiosensitivity in ESCC.

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A Cu-catalyzed oxidative dual arylation of active alkenes via the cleavage of two C-N bonds of 3-aminoindazoles is presented for constructing isoquinolinones. Importantly, 3-aminoindazoles are used as efficient arylating agents through a radical process. This method has a good substrate scope and functional group compatibility.

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An iron-promoted oxidative tandem alkylation/cyclization of ynones with 4-alkyl-substituted 1,4-dihydropyridines for the efficient synthesis of 2-alkylated indenones is described. The process occurs via oxidative homolysis of a C-C σ-bond in 1,4-dihydropyridines to generate an alkyl radical followed by the addition of C-C triple bonds in ynones and intramolecular cyclization. A wide range of alkyl radicals could be efficiently transferred to generate a series of synthetically useful 2-alkylated indenones with excellent selectivity under mild conditions.

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A method for the preparation of 3-alkylated spiro[4.5]trienones via alkylation/ipso-cyclization of activated alkynes with 4-alkyl-DHPs under transition-metal-free conditions is proposed. This alkylation successively undergoes the generation of alkyl radicals, addition of alkyl radicals to the alkynes, and intramolecular ipso-cyclization. The mechanism studies suggest that the alkylation/ipso-cyclization involves a radical process. This ipso-cyclization procedure shows a series of advantages, such as accessibility, mild conditions, high efficiency, greater safety, and an environmentally friendly method.

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The transition-metal-free alkylation/cyclization of activated alkenes using Hantzsch ester derivatives as effective alkyl reagents is described. A wide variety of valuable oxindoles was constructed in a single step with excellent selectivity. The reaction occurs through the formation of alkyl radical species followed by the tandem addition/annulation of olefins under oxidative conditions. This protocol is expected to offer inspiration for developing novel and efficient applications of Hantzsch esters in organic synthesis.

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BACKGROUND: Squamous cell cancers in the hypopharynx (HP) and cervical esophagus (CE) are different diseases with different staging systems and treatment approaches. Pharyngoesophageal junction (PEJ) tumor involves both the hypopharynx and the cervical esophagus simultaneously, but few reports focused on PEJ tumors. This study aimed to clarify clinical characteristics and the treatment approaches of PEJ tumors. PATIENTS AND METHODS: A total of 222 patients with squamous cell carcinoma in the HP, PEJ, and CE were collected between January 2008 and June 2018 in Fudan University Shanghai Cancer Center. We compared different lymph node metastatic patterns of three diseases above and the survival of different tumor locations, different lymph node metastasis, and different radiotherapy approaches. RESULTS: For HP, PEJ, and CE cancer, the upper and middle cervical lymph node metastatic rates were 85.7%, 47.1%, and 5.8%, respectively; the lower cervical lymph node metastatic rates were 36.7%, 42.9%, and 35.0%, respectively; and the mediastinal lymph node metastatic rates were 2.0%, 72.9%, and 80.6%, respectively. The 3-year overall survival rates were 69.5% in the HP group, 52.0% in the PEJ group, and 69.6% in the CE group (p = 0.024). No survival differences were found between the involved-field-irradiation and elective-node-irradiation subgroups among PEJ tumors (p = 0.717 for OS and p = 0.454 for PFS, respectively). CONCLUSION: HP cancers had a high prevalence in all cervical lymph node metastases, while CE cancers had a lower prevalence in the cervical and mediastinal lymph node metastases. PEJ cancer had the combined metastatic patterns of both HP and CE cancers. Involved field irradiation was feasible in chemoradiotherapy for PEJ cancers.

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Resilience of rural communities is becoming increasingly important to contemporary society. In this study we used a quantitative method to measure the resilience regulating ability of rural communities close to urban areas-in Licheng Subdistrict, Guangzhou City, China. The main results are as follows: (1) Rural systems close to urban areas display superior adapting and learning abilities and have a stronger overall resilience strength, the spatial distribution of which is characterized by dispersion in whole and aggregation in part; (2) the resilience of most rural economic subsystems can reach moderate or higher levels with apparent spatial agglomeration, whilst the ecological subsystem resilience and social resilience are generally weaker; the spatial distribution of the former shows a greater regional difference while the latter is in a layered layout; (3) some strategies such as rebuilding a stable ecological pattern, making use of urban resources and cultivating rural subjectivity are proposed on this basis, in order to promote the sustainable development of rural areas and realize rural revitalization. This work also gives suggestion for the creation of appropriate and effective resilience standards specifically targeted for rural community-aiming to achieve the delivery of local sustainability goals.

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Land-use change accounts for a large proportion of the carbon emissions produced each year, especially in highly developed urban agglomerations. In this study, we combined remote sensing data and socioeconomic data to estimate land-use-related carbon emissions, and applied the logarithmic mean Divisia index (LMDI) method to analyze its influencing factors, in the Pearl River Delta (PRD) of China in 1990-2015. The main conclusions are as follows: (1) The total amount of land-use-related carbon emissions increased from 684.84 × 104 t C in 1990 to 11,444.98 × 104 t C in 2015, resulting in a net increase of 10,760.14 × 104 t (16.71 times). (2) Land-use-related carbon emissions presented a "higher in the middle and lower on both sides" spatial distribution. Guangzhou had the highest levels of carbon emissions, and Zhaoqing had the lowest; Shenzhen experienced the greatest net increase, and Jiangmen experienced the least. (3) The land-use-related carbon emissions intensity increased from 4795.76 × 104 Yuan/t C to 12,143.05 × 104 Yuan/t C in 1990-2015, with the greatest increase seen in Huizhou and the lowest in Zhongshan. Differences were also found in the spatial distribution, with higher intensities located in the south, lower intensities in the east and west, and medium intensities in the central region. (4) Land-use change, energy structure, energy efficiency, economic development, and population all contributed to increases in land-use-related carbon emissions. Land-use change, economic development and population made positive contributions, while energy efficiency and energy structure made negative contributions. At last, we put forward several suggestions for promoting low-carbon development, including development of a low-carbon and circular economy, rationally planning land-use structure, promoting reasonable population growth, improving energy efficiency and the energy consumption structure, and advocating low-carbon lifestyles. Our findings are useful in the tasks related to assessing carbon emissions from the perspective of land-use change and analyzing the associated influencing factors, as well as providing a reference for realizing low-carbon and sustainable development in the PRD.

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Covering: 2010 to 2020Benzocycloheptane is a fundamental and unique structural motif found in pharmaceuticals and natural products. The total syntheses of natural products bearing the benzocycloheptane subunit are challenging and there are only a few efficient approaches to access benzocycloheptane. Thus, new methods and innovative strategies for preparing such natural products need to be developed. In this review, recent progress in the total syntheses of natural products bearing the benzocycloheptane motif is presented, and key transformations for the construction of benzocycloheptane are highlighted. This review provides a useful guide for those engaged in the syntheses of natural products containing the benzocycloheptane motif.

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Type II intramolecular cycloadditions ([4+2], [4+3], [4+4] and [5+2]) have emerged recently as an efficient and powerful strategy for the construction of bridged ring systems. In general, type II cycloadditions provide access to a wide range of bridged bicyclo[m.n.1] ring systems with high regio- and diastereoselectivity in an easy and straightforward manner. In each section of this review, an overview of the corresponding type II cycloadditions is presented, which is followed by highlights of method development and synthetic applications in natural product synthesis. The goal of this review is to provide a survey of recent advances in the field covering literature up to 2020. The review will serve as a useful reference for organic chemists engaged in the total synthesis of natural products containing bridged bicyclo[m.n.1] ring systems and provide strong stimulus for invention and further advances in this exciting research field.

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BACKGROUND: Epidermal growth factor receptor (EGFR) is reportedly overexpressed in most esophageal tumors, but most targeted therapies showed no efficacy in non-selected patients. This study aims at investigating the adaptive cetuximab subset in a cohort of esophageal squamous cell carcinoma (ESCC) patient-derived xenografts (PDXs). METHODS: A large panel of ESCC PDXs has been established. The copy number, mRNA expression and immunohistochemistry (IHC) of key EGFR pathways have been examined along with cetuximab response. A preclinical trial on a randomly selected cohort of 16 ESCC PDXs was conducted, and the genomic annotations of these models were compared against the efficacy readout of the mouse trial. RESULTS: The trial identified that 7 of 16 (43.8%) responded to cetuximab (ΔT/ΔC <0 as responders). The gene amplification and expression analysis indicated that EGFR copy number ≥5 (P=0.035), high EGFR mRNA expression (P=0.001) and IHC score of 2-3 (P=0.034) are associated with tumor growth inhibition by cetuximab, suggesting EGFR may function as a single predictive biomarker for cetuximab response in ESCC. CONCLUSIONS: Overall, our results suggest that an ESCC subtype with EGFR amplification and overexpression benefits from cetuximab treatment, which warrants further clinical confirmation.

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INTRODUCTION: Concurrent chemoradiation is the standard therapy for patients with local advanced oesophageal carcinoma unsuitable for surgery. Paclitaxel is an active agent against oesophageal cancer and it has been proved as a potent radiation sensitiser. There have been multiple studies evaluating paclitaxel-based chemoradiation in oesophageal cancer, of which the results are inspiring. However, which regimen, among cisplatin (TP), carboplatin (TC) or fluorouracil (TF) in combination with paclitaxel concurrent with radiotherapy, provides best prognosis with minimum adverse events is still unknown and very few studies focus on this field. The purpose of this study is to confirm the priority of TF to TP or TF to TC concurrent with radiotherapy in terms of overall survival and propose a feasible and effective plan for patients with local advanced oesophageal cancer. METHODS AND ANALYSIS: ESO-Shanghai 2 is a three-arm, multicenter, open-labelled, randomised phase III clinical trial. The study was initiated in July 2015 and the duration of inclusion is expected to be 4 years. The study compares two pairs of regimen: TF versus TP and TF versus TC concurrent with definitive radiotherapy for patients with oesophageal squamous cell carcinoma (OSCC). Patients with histologically confirmed OSCC (clinical stage II, III or IVa based on the sixth Union for International Cancer Control-tumour, node, metastasis classification) and without any prior treatment of chemotherapy, radiotherapy or surgery against oesophageal cancer will be eligible. A total of 321 patients will be randomised and allocated in a 1:1:1 ratio to the three treatment groups. Patients are stratified by lymph node status (N0, N1, M1a). The primary endpoint is overall survival and the secondary endpoint is progression-free survival and adverse events. ETHICS AND DISSEMINATION: This trial has been approved by the Fudan University Shanghai Cancer Centre Institutional Review Board. Trial results will be disseminated via peer reviewed scientific journals and conference presentations. TRIAL STATUS: The trial was initiated in July 2015 and is currently recruiting patients in all of the participating institutions above. TRIAL REGISTRATION NUMBER: NCT02459457.

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