Publications by authors named "Hui-Cheng Cheng"

Construction of a carbon-nitrogen bond is one of the most prevalent operations in nature and organic synthesis. The resulting amino compounds are privileged structural fragments in natural products, pharmaceutical drugs, and functional materials. With the rapid advancement of C-H bond activation, directing-group strategies in C-H amination catalyzed by rhodium have emerged.

View Article and Find Full Text PDF

A general and efficient method for the synthesis of tertiary amides has been developed via the copper-catalyzed aerobic oxidative amidation of tertiary amines. Due to the use of the O2 oxidant, various functional groups were well tolerated under the present conditions. Extensive substrates studies demonstrated its potential as a practical approach for the synthesis of tertiary amides.

View Article and Find Full Text PDF

Objective: The objective of our study was to evaluate the CT characteristics of globe rupture.

Materials And Methods: The medical records of patients seen in the emergency department with blunt, penetrating, or explosive orbit injury were retrospectively reviewed. A total of 75 patients (76 injured globes) were included (56 males and 19 females; average age, 45.

View Article and Find Full Text PDF

Background: This study investigated one-stop breast screening combining magnetic resonance imaging (MRI) and ultrasound (US) in asymptomatic Asian women.

Methods: 3,586 asymptomatic women (mean age, 45.3 years) were retrospectively analyzed by breast MRI followed by US.

View Article and Find Full Text PDF

Background: Recent refinements of lung MRI techniques have reduced the examination time and improved diagnostic sensitivity and specificity. We conducted a study to assess the feasibility of MRI for the detection of primary lung cancer in asymptomatic individuals.

Methods: A retrospective chart review was performed on images of lung parenchyma, which were extracted from whole-body MRI examinations between October 2000 and December 2007.

View Article and Find Full Text PDF

The purpose of this study was to investigate the neural activity of electroacupuncture (EA) quantitatively. The responses of Sprague-Dawley rats' brain to EA on acupoints--Hegu (LI 4) and Neiguan (PC 6)--were detected by monocrystalline iron oxide nanoparticle (MION)-enhanced functional magnetic resonance imaging (MION-fMRI), which is a 1.5 T horizontal spectrometer equipped with a circular polarized extremity coil.

View Article and Find Full Text PDF

Purpose: This study presents 3-dimensional, contrast-enhanced, magnetic resonance (MR) angiographic appearances of the carotid artery after stenting.

Methods: The authors reviewed contrast-enhanced MR angiograms of 18 carotid arteries in 13 patients. These arteries were not stenotic or occluded in the stented segment, as shown on carotid angio-grams (11 patients) or carotid Doppler images (2 patients) obtained later.

View Article and Find Full Text PDF

The aetiology of primary cough headache (PCH) is obscure. The aim of this study was to investigate the magnetic resonance (MR) morphometric characteristics of the posterior cranial fossa (PCF) in patients with PCH. Eighteen consecutive patients with PCH (14M/4F, mean age 75.

View Article and Find Full Text PDF

Acupuncture analgesia is an important issue in veterinary medicine. This study was designed to elucidate central modulation effects in response to electroacupuncture (EA) at different acupoints. Manganese-enhanced functional magnetic resonance imaging was performed in Sprague-Dawley rats after sham acupuncture, sham EA, or true EA at somatic acupoints.

View Article and Find Full Text PDF

Dynamic-susceptibility-contrast MR perfusion imaging is a widely used imaging tool for in vivo study of cerebral blood perfusion. However, visualization of different hemodynamic compartments is less investigated. In this work, independent component analysis, thresholding, and Bayesian estimation were used to concurrently segment different tissues, i.

View Article and Find Full Text PDF

Images acquired using the TrueFISP technique (true fast imaging with steady-state precession) are generally believed to exhibit T(2)/T(1)-weighting. In this study, it is demonstrated that with the widely used half-flip-angle preparation scheme, approaching the steady state requires a time length comparable to the scan time such that the transient-state response may dominate the TrueFISP image contrast. Two-dimensional images of the human brain were obtained using various phase-encoding matrices to investigate the transient-state signal behavior.

View Article and Find Full Text PDF