Implantation of Active Can Implantable Defibrillators in the right Pectoral Region

Routinely the active can ICD is placed in the left side pectoral position, which theoretically gives optimal conditions for a low defibrillation threshold. Some patients, bowever, demand a right pectoral position, which possibly could result in a bigger defibrillation threshold. A right pectoral position was used in 3 of 85 active can ICDs implanted in our institution from 1994. the DFT was 12 J in two and 18 f in one patient. Thus, right pectoral implantation is feasible and offers an alternative approach in selected patients.     

水飞蓟宾构象的理论研究

目的 水飞蓟宾RRRR对映体分子中存在多个可变的二面角，可以产生许多立体构象，旨在从理论上寻找其合理构象。方法 采用二面角系统搜索后，结合AM1方法确定主要构象，以B3LYP／6—31G*方法优化构型后，在B3LYP／3—21G水平计算了振动频率和热力学参数。结果 得到了各二面角的分布情况，找出了主要的局部构象，明确了C9-C11和C18-C22旋转主要引起分子构象变化，4种主要构象能量差异较小，都有存在的可能性，二面角C19-C18-C22-C32和C8-C9-C11-C16变化的能量曲线表明，C9-C11旋转的能垒很小，受C19的羟甲基影响，C18-C22旋转能垒较大。结论 水飞蓟宾RRRR对映体主要以4种构象的形式存在。     

FRu（phen）2（3，8—2R—phen）-]^2＋（R=OH，H，F）电子结构与抗癌活性研究

用密度泛函(DFT)法，对配合物[Ru(phen)2(3，8-2R—phen)^2 (R=OH，H，F)进行了理论计算研究。探讨了配合物的电子结构与其抗癌活性的关系：主配体上3，8位上F原子的取代有利于配合物与DNA的作用，增加配合物的抗癌活性。计算结果能较好地预测配合物与DNA的作用强度、抗癌活性及指导具有较高抗癌活性配合物的合成。     

State-of-the-art Tools for Computational Site of Metabolism Predictions: Comparative Analysis,Mechanistical Insights,and Future Applications

In drug design, it is crucial to have reliable information on how a chemical entity behaves in the presence of metabolizing enzymes. This requires substantial experimental efforts. Consequently, being able to predict the likely site/s of metabolism in any compound, synthesized or virtual, would be highly beneficial and time efficient.

In this work, six different methodologies for predictions of the site of metabolism (SOM) have been compared and validated using structurally diverse data sets of drug-like molecules with well-established metabolic pattern in CYP3A4, CYP2C9, or both. Three of the methods predict the SOM based on the ligand's chemical structure, two additional methods use structural information of the enzymes, and the sixth method combines structure and ligand similarity and reactivity. The SOM is correctly predicted in 50 to 90% of the cases, depending on method and enzyme, which is an encouraging rate. We also discuss the underlying mechanisms of cytochrome P450 metabolism in the light of the results from this comparison.     

Multi-level basis selection of wavelet packet decomposition tree for heart sound classification

Wavelet packet transform decomposes a signal into a set of orthonormal bases (nodes) and provides opportunities to select an appropriate set of these bases for feature extraction. In this paper, multi-level basis selection (MLBS) is proposed to preserve the most informative bases of a wavelet packet decomposition tree through removing less informative bases by applying three exclusion criteria: frequency range, noise frequency, and energy threshold. MLBS achieved an accuracy of 97.56% for classifying normal heart sound, aortic stenosis, mitral regurgitation, and aortic regurgitation. MLBS is a promising basis selection to be suggested for signals with a small range of frequencies.     

The Effects of Oxygen Functional Groups on Graphene Oxide on the Efficient Adsorption of Radioactive Iodine

Oxygen-containing functional groups tend to induce a strong interaction between solid adsorbents and iodine molecules, yet have not been systematically investigated. Herein, on the basis of a series of nitric acid-treated graphene oxide (GO) with different contents of oxygen functional groups for iodine adsorption, it was found that the iodine uptake capacity is proportionate to the oxygen content and the diversities of oxygen-containing groups. The density functional theory (DFT) calculation results also suggest that oxygen-containing groups result in strong interactions between iodine molecules and the adsorbents through a covalent bond-forming process, among which -OH groups possess a higher adsorption energy averagely. Such theoretical and experimental work deepens our understanding of the effects of oxygen functional groups on iodine adsorption and provides novel ideas for future design and synthesis of high-performance solid adsorbents for radioactive iodine.     

Electronic Structure and Surface Properties of Copper Thiocyanate: A Promising Hole Transport Material for Organic Photovoltaic Cells

Considering the significance of hexagonal copper thiocyanate (β-CuSCN) in several optoelectronic technologies and applications, it is essential to investigate its electronic structure and surface properties. Herein, we have employed density functional theory (DFT) calculations to characterise the band structure, density of states, and the energy-dependent X-ray photoelectron (XPS) valence band spectra at variable excitation energies of β-CuSCN. The surface properties in the absence and presence of dimethyl sulfoxide (DMSO), a solvent additive for improving perovskite solar cells’ power conversion efficiency, have also been systematically characterised. β-CuSCN is shown to be an indirect band gap material (E_g = 3.68 eV) with the valence band edge demonstrated to change from being dominated by Cu-3d at soft X-ray ionisation photon energies to Cu-3p at hard X-ray ionisation photon energies. The adsorption energy of dimethyl sulfoxide (DMSO) on the (100) and (110) β-CuSCN surfaces is calculated at −1.12 and −0.91 eV, respectively. The presence of DMSO on the surface is shown to have a stabilisation effect, lowering the surface energy and tuning the work function of the β-CuSCN surfaces, which is desirable for organic solar cells to achieve high power conversion efficiencies.