Methods that enable the direct C−H alkoxylation of complex organic molecules are significantly underdeveloped, particularly in comparison to analogous strategies for C−N and C−C bond formation. In ...particular, almost all methods for the incorporation of alcohols by C−H oxidation require the use of the alcohol component as a solvent or co‐solvent. This condition limits the practical scope of these reactions to simple, inexpensive alcohols. Reported here is a photocatalytic protocol for the functionalization of benzylic C−H bonds with a wide range of oxygen nucleophiles. This strategy merges the photoredox activation of arenes with copper(II)‐mediated oxidation of the resulting benzylic radicals, which enables the introduction of benzylic C−O bonds with high site selectivity, chemoselectivity, and functional‐group tolerance using only two equivalents of the alcohol coupling partner. This method enables the late‐stage introduction of complex alkoxy groups into bioactive molecules, providing a practical new tool with potential applications in synthesis and medicinal chemistry.
Partner up: Photocatalysis offers a one‐step strategy to selectively functionalize the benzylic positions of electron‐rich arenes with alcohols. It merges the photoredox activation of arenes with copper(II)‐mediated oxidation of the resulting benzylic radicals, enabling the introduction of benzylic C−O bonds with high site selectivity, chemoselectivity, and functional‐group tolerance using only two equiv of the alcohol coupling partner.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
We report the enantioselective 2+2 cycloaddition of simple cinnamate esters, the products of which are useful synthons for the controlled assembly of cyclobutane natural products. This method ...utilizes a cocatalytic system in which a chiral Lewis acid accelerates the transfer of triplet energy from an excited-state Ir(III) photocatalyst to the cinnamate ester. Computational evidence indicates that the principal role of the Lewis acid cocatalyst is to lower the absolute energies of the substrate frontier molecular orbitals, leading to greater electronic coupling between the sensitizer and substrate and increasing the rate of the energy transfer event. These results suggest Lewis acids can have multiple beneficial effects on triplet sensitization reactions, impacting both the thermodynamic driving force and kinetics of Dexter energy transfer.
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IJS, KILJ, NUK, PNG, UL, UM
The synthesis of unsymmetrical cyclobutanes by controlled heterodimerization of olefins remains a substantial challenge, particularly in an enantiocontrolled fashion. Shown herein is that chiral ...Lewis acid catalyzed triplet sensitization enables the synthesis of highly enantioenriched diarylcyclobutanes by photocycloaddition of structurally varied 2′‐hydroxychalcones with a range of styrene coupling partners. The utility of this reaction is demonstrated through the direct synthesis of a representative norlignan cyclobutane natural product.
Cross‐products: Lewis acid catalyzed triplet sensitization enables the highly enantioselective crossed cycloaddition of chalcones and styrenes to forge cyclobutane cores. These cores are found in multiple bioactive natural products.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
This study analyzed the prognostic significance of clinico-pathologic factors, including the number of metastatic lymph nodes (LNs) and lymph node ratio (LNR), in patients with papillary thyroid ...carcinoma (PTC), and attempted to construct a disease recurrence prediction model using machine learning techniques. We retrospectively analyzed clinico-pathologic data from 1040 patients diagnosed with PTC between 2003 and 2009. We analyzed clinico-pathologic factors related to recurrence through logistic regression analysis. Among the factors that we included, only sex and tumor size were significantly correlated with disease recurrence. Parameters such as age, sex, tumor size, tumor multiplicity, ETE, ENE, pT, pN, ipsilateral central LN metastasis, contralateral central LNs metastasis, number of metastatic LNs, and LNR were input for construction of a machine learning prediction model. The performance of five machine learning models related to recurrence prediction was compared based on accuracy. The Decision Tree model showed the best accuracy at 95%, and the lightGBM and stacking model together showed 93% accuracy. Among those factors mentioned above, LNR and contralateral LN metastasis were used as important features in all machine learning prediction models. We confirmed that all machine learning prediction models showed an accuracy of 90% or more for predicting disease recurrence in PTC. LNR and contralateral LN metastasis were used as important features for constructing a robust machine learning prediction model. In the future, we have a plan to perform large-scale multicenter clinical studies to improve the performance of our prediction models and verify their clinical effectiveness.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
ObjectivesTo evaluate the effect of inferior oblique (IO) myectomy on ocular torsion according to the absence of the trochlear nerve in unilateral congenital superior oblique palsy (UCSOP).MethodsWe ...retrospectively reviewed the clinical data of patients who had been diagnosed with UCSOP and underwent ipsilateral IO myectomy (n = 43). Patients were classified into the present and absent groups according to the absence of the trochlear nerve and superior oblique hypoplasia on magnetic resonance imaging (MRI). For quantitative analysis of ocular torsion, disc-fovea angles (DFA) were collected in both eyes using fundus photographs taken within three months before surgery and one month after surgery.ResultsDFA of the paretic eye did not differ according to the absence of the trochlear nerve (9.4±5.6° in the present group vs. 11.0±5.4° in the absent group, p = 0.508). However, the present group had a larger DFA in the non-paretic eye than the absent group (14.1±6.7° in the present group vs. 8.0±5.0° in the absent group, p = 0.003). The change of ocular torsion after IO myectomy in the paretic eye was -5.3±3.7° in the present group and -4.8±3.5° in the absent group, respectively (p = 0.801). In the non-paretic eye, the change in DFA was -1.5±3.0° in the present group, which was larger than that in the absent group (0.7±2.6°, p = 0.047). In the multivariate analysis, the change in DFA was correlated with only the preoperative DFA (standardized β = -0.617, p<0.001 in the paretic eye, and standardized β = -0.517, p<0.001 in the non-paretic eye).ConclusionsIn the paretic eye, there was no significant difference in the change of ocular torsion between both groups, whereas in the non-paretic eye, the present group had a larger change in DFA after IO myectomy than the absent group. However, in the multivariable analysis, the change in ocular torsion was significantly correlated with preoperative excyclotorsion but not with the presence of the trochlear nerve itself.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Previous studies have documented the protective effects of social participation on depression in older adults. In this study, we investigated the association between social participation and ...depressive symptoms and the associated gender difference in older adults. In addition, we explored the mediating role of emotional social support in the association between social participation and depressive symptoms. We collected data from 4751 community-dwelling adults aged 60 and above from the Korean Retirement and Income Study (KReIS) conducted in 2017 and 2018. The relationship between social participation (participation in different types of activities, frequency of participation, and the number of activities participated) and the risk for depressive symptoms was examined. Older adults who participated in social activity, volunteer work, and donation had decreased risk of depressive symptoms. More frequent and more diverse participation in activities further reduced the risk. Overall, women benefited more from social participation than men. Importantly, emotional social support significantly mediated the relationship between social participation and depressive symptoms. Social participation was associated lower odds for depression in older adults, particularly in older women. Our findings provided one of very few pieces of evidence that documents the mediating role of emotional social support in the relationship between social participation and depression among the elderly.
•Cross-sectional data from 4751 community-dwelling adults aged 60 and older.•Social participation was associated with lower odds for depression.•Frequent and diverse social participation predicted lower odds of depression.•Gender difference in the association between social participation and depression.•Emotional social support mediated link between social participation and depression.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
For ideal clinical benefit, human immunodeficiency virus (HIV)-infected individuals should receive continuous medication. This is the first nationwide antiretroviral therapy (ART) adherence study in ...Asia, where medication monitoring at national level is systemically available. We estimated the ART adherence of incident HIV-infected individuals and investigated factors affecting low medication adherence using the national health insurance (NHI) claims data from 2007 to 2016. Medication possession ratio (MPR) was used to measure medication adherence and risk factors were identified by multivariable logistic regression analysis. Of the 8,501 newly diagnosed HIV-infected individuals during 2009-2016 with at least one ART prescription, 70.4% of HIV patients had adequate adherence to ART defined as MPR ≥95%. Requiring prophylactic antibiotics, female gender, age of 0-19 and same or over 50 s compared to 30-39, and having a history of malignancy, lower socioeconomic status, not visiting tertiary hospital, and being diagnosed in the earlier years were risk factors for lower adherence (Odds ratio 1.7, 1.6, 1.6, 1.4, 1.6, 2.1, 1.2, and 1.6 to 3.8 respectively). Health authority should take into consideration of these modifiable and unmodifiable barriers to establish sustainable monitoring system at national level and to improve adherence.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
A kenaf-derived activated carbon (KAC) for a high-power density supercapacitor was developed in this study through phosphoric acid activation. The N2/77K isothermal adsorption–desorption curve was ...used to estimate the textural properties of KAC based on BET and BJH and the pore size distribution based on NLDFT. The electrochemical properties of KAC were analyzed by using the coin-type cell applying 1 M SPBBF4/PC electrolyte, and the specific surface area and total pore volume were 1490–1942 m2/g and 1.18–3.18 cm3/g, respectively. The pore characteristics of KAC varied according to the activation temperature, and most KAC showed a mesoporous structure. As the activation temperature increased, the mesopore volume increased up to 700 °C, then decreased. The mesoporous structure of KAC resulted in a substantial decrease in the Warburg impedance as the ion diffusion resistance decreased. Hence, the specific capacitance of KAC decreased from 82.9 F/g to 59.48 F/g as the charge–discharge rate increased from 1 mA/g to 10 mA/g, with the rate of reduction at approximately 30%. The rate of reduction of KAC’s specific capacitance was 50% lower compared with commercial activated carbon; hence, KAC is a more suitable electrode-active material for high power density supercapacitors.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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This study provides a comprehensive review of the current research status of fiber reinforced concrete (FRC), specifically focusing on their structural and functional properties and ...potential applications in the construction industry. The research evaluates the effect of adding different types of fibers, such as steel, glass, and carbon, to concrete on its compressive, tensile, and flexural strength. The study also explores the impact of compacting methods and site conditions on the workability of FRC. In addition, the study examines the functional behavior of FRC, such as the reduction in electrical resistance achieved by adding conductive materials like CNTs, and the use of self-sensing materials for structural control and monitoring. The study also considers the potential of FRC for electromagnetic interference shielding to protect electronic devices from harmful radiation. Overall, the study provides valuable design guidelines for the use of FRC composites in construction projects.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
After spinal cord injury (SCI), tight junction (TJ) protein degradation increases permeability and disrupts the blood–spinal cord barrier (BSCB). The BSCB is primarily formed of endothelial cell, ...which forms a specialized tight seal due to the presence of TJs. BSCB disruption after SCI allows neutrophil infiltration. Matrix metalloproteinase (MMP)-8 is believed to be mainly expressed by neutrophils and is quickly released upon neutrophil activation. Here, we determined whether MMP-8 is involved in the TJ protein degradation in endothelial cells and also determined its role in the neuroinflammation after SCI. MMP-8 recombinant protein treatment increases the TNF-α expression and decreased the TJ (occludin and zonula occludens-1) protein expression in the endothelial cells. Likewise, specific MMP-8 inhibitor (MMP-8I) significantly prevented the TNF-α-induced decrease in the expression of TJ protein in endothelial cells. Furthermore, MMP-8 expression was significantly increased 1 and 3 days after moderate compression (35 g for 5 min at T10 level) SCI, whereas TJ protein levels decreased as determined qRT-PCR, western blotting, and immunohistochemistry. MMP-8 was inhibited directly using a MMP-8I (5 mg/kg) and indirectly by reducing neutrophil infiltration with sivelestat sodium (50 mg/kg) or using the antioxidant
N
-acetyl-
l
-cysteine (100 mg/kg). The MMP-8I significantly decreased TNF-α expression, IL-6, and iNOS expression and increased TJ protein expression after SCI. In addition, MMP-8I significantly lessens the amount of Evans blue dye extravasation observed after injury. Thus, our result suggests that MMP-8 plays an imperative role in inflammation and degradation of TJ proteins. Increased MMP-8 expression was associated with the early inflammatory phase of SCI. Inhibiting MMP-8 significantly attenuated SCI-induced inflammation, BSCB breakdown, and cell injury.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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