Further Study of (Pincer)Iridium-Catalyzed Aromatic C-H Borylation and the Development of New Arylgermanes for Palladium-Catalyzed Cross-Coupling Reactions

Metal-catalyzed cross-coupling reactions of aryl halides or pseudohalides with nucleophiles have been ubiquitous and powerful tools to construct new C–C bonds in synthetic organic chemistry. Among the nucleophiles, arylboronic acids and their esters (arylboronates) are the most popular reagents due to their versatile reactivity and reasonable stability. In 2016, our group reported a highly efficient aromatic C–H borylation catalyzed by (POCOP)Ir complexes. Here we continued the development of the (pincer)Ir-catalyzed system by surveying a series of iridium and rhodium complexes of pincer ligands. We have disclosed that only iridium complexes supported by pincer ligands with a central aryl donor are capable of catalyzing aromatic C–H borylation. The newly tested (PCP)Ir complex has shown improved chemoselectivity (C–H borylation vs. olefin hydroboration, and sp² C–H vs. sp³ C–H borylation) compared to the previously reported (POCOP)Ir complexes. In terms of regioselectivity, C–H borylation of PhF showed certain variations when different precatalysts were examined. On the other hand, C–H borylation of PhCF₃ generally followed the state-of-the-art C–H borylation catalyzed by the iridium complexes supported by neutral bidentate ligands. In addition to arylboron reagents, group 14 main group reagents have also shown their utility in cross-coupling chemistry. Germanium, positioned between silicon and tin on the periodic table, however, receives much less attention. There are only a few examples of cross-coupling reactions using organogermanes as nucleophiles in the existing literature. Here we have developed a robust and efficient ligandless Pd-catalyzed germylation protocol to prepare arylgermanes with tert-butoxy substituents from aryl bromides. The germylation reagent, sodium tri-tert-butoxygermanate, is readily prepared from commercially available GeCl₂·C₄H₈O₂. This highly efficient catalytic system has a wide substrate scope with excellent isolated yields and only produces NaBr as a byproduct. The newly prepared arylgermanes have been studied in the subsequent Pd-catalyzed cross-coupling reaction. We undertook a detailed screening of reaction conditions to identify the optimal condition. Using fluoride as a base is required for successful catalysis and adding water significantly increases the yield of the desired cross-coupling product. The possible roles of fluoride and water have been discussed. The reaction scope and preliminary chemoselective cross-coupling experiments have shown that the newly prepared arylgermanes indeed have useful and unique reactivity compared to the existing reagents

Influences of Satisfaction with Telecare and Family Trust in Older Taiwanese People

The level of trust given towards telecare by the family members of older people using the service is extremely important. Family trust may be an influential factor in deciding whether to use such services. This study focuses on older people’s satisfaction with telecare and examines their family’s trust in telecare services. Influences on intention to continue using telecare services are also explored. A questionnaire-based survey on 60 communities dwelling older people who had been receiving telecare services in the past two years was employed. This study developed a satisfaction and trust scale based on previous studies. Our results show that older people’s satisfaction with telecare services and families’ trust were influential in decided whether to continue to use of telecare services. These findings can help medical institutions to better insight into the user experience of telecare to help them provide future services that better comply with clients’ desires and requirements

An Exploration of Intent to Use Telehealth at Home for Patients with Chronic Diseases

Telecare is defined as care practiced at a distance. It is an effective strategy for improving the self-health care management of home-patients with chronic diseases. The purpose of this study was to explore the intent to use of telehealth patients. The correlation between the self-care behaviors, the intent to use of telehealth, and the effects on physiological indicators of patients with chronic disease at home were studied. A cross-sectional study design employing purposive sampling was selected. The structured questionnaire ‘Telecare Usage Intention Scale and Self-Care Behavior Scale’ were used, ‘HbA1c, glucose levels and monthly blood pressure measurements’ were analyzed in this thirteen month study. The self-care behaviors of the participants were positively correlated with their intent to use telehealth (p < 0.01). The results also indicated that HbA1c, glucose levels and frequency BP measurement of the participants improved significantly after using telecare (p < 0.005). The results indicated a strong intent to use telehealth and positive perception of telecare services by in-home patients with a chronic disease. Telehealth improves the self-care behavior of in-home chronic disease patients and enhances medical professionals’ ability to deliver quality and effective healthcare

Prediction of Both Electrical and Mechanical Reverse Remodeling On Acute Electrocardiogram Changes After Cardiac Resynchronization Therapy

Background: The development of both electrical reverse remodeling and mechanical reverse remodeling (ERR+MRR) after cardiac resynchronization therapy (CRT) implantation could reduce the incidence of lethal arrhythmia, hence the prediction of ERR+MRR is clinically important. Methods and Results: Eighty-three patients (54 male; 67±12 years old) with CRT \u3e6 months were enrolled. ERR was defined as baseline intrisic QRS duration (iQRSd) shortening ≥10 ms in lead II on ECG after CRT, and MRR as improvement in LVEF ≥25% on echocardiography after CRT. Acute ECG changes were measure by comparing the pre-implant and immediate post-implant ECG. Ventricular arrhythmia episodes, including ventricular tachycardia and ventricular fibrillation, detected by the implanted device were recorded. Patients were classified as ERR only (n=12), MRR only (n+23), ERR+MRR (n=26), or non-responder (ERR— & Mrr—, n=22). On multivariate regression analysis, difference between baseline intrinsic QRS and paced QRS duration (ΔQRSD) \u3e35 ms was a significant predictor of ERR+MRR (sensitivity, 68%; specificity, 64%; AUC, 0.7; P=0.003), and paced QTc \u3e443 ms was a negative predictor of ERR+MRR (sensitivity, 78%; specificity, 60%; AUC, 0.7; P-0.002). On Cox proportional hazard modeling, ERR+MRR may reduce risk of ventricular arrhythma around 70% compared with non-reponder (HR, 0.29; 95% CI: 0.13-0.65). Conclusions: Acute ECG Changes after CRT were useful predictors of ERR+MRR. ERR+MRR was also a protective factor for ventricular arrhythmia

The Feasibility of Differentiating Lewy Body Dementia and Alzheimer’s Disease by Deep Learning Using ECD SPECT Images

The correct differential diagnosis of dementia has an important impact on patient treatment and follow-up care strategies. Tc-99m-ECD SPECT imaging, which is low cost and accessible in general clinics, is used to identify the two common types of dementia, Alzheimer’s disease (AD) and Lewy body dementia (LBD). Two-stage transfer learning technology and reducing model complexity based on the ResNet-50 model were performed using the ImageNet data set and ADNI database. To improve training accuracy, the three-dimensional image was reorganized into three sets of two-dimensional images for data augmentation and ensemble learning, then the performance of various deep learning models for Tc-99m-ECD SPECT images to distinguish AD/normal cognition (NC), LBD/NC, and AD/LBD were investigated. In the AD/NC, LBD/NC, and AD/LBD tasks, the AUC values were around 0.94, 0.95, and 0.74, regardless of training models, with an accuracy of 90%, 87%, and 71%, and F1 scores of 89%, 86%, and 76% in the best cases. The use of transfer learning and a modified model resulted in better prediction results, increasing the accuracy by 32% for AD/NC. The proposed method is practical and could rapidly utilize a deep learning model to automatically extract image features based on a small number of SPECT brain perfusion images in general clinics to objectively distinguish AD and LBD

Cobalt Silicide Nanostructures: Synthesis, Electron Transport, and Field Emission Properties

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