Halogen−π Interactions between Benzene and X₂/CX₄ (X = Cl, Br): Assessment of Various Density Functionals with Respect to CCSD(T)

Youn, Il Seung,Kim, Dong Yeon,Cho, Woo Jong,Madridejos, Jenica Marie L.,Lee, Han Myoung,Kołaski, Maciej,Lee, Joonho,Baig, Chunggi,Shin, Seung Koo,Filatov, Michael,Kim, Kwang S. American Chemical Society 2016 The Journal of physical chemistry A Vol.120 No.46

<P>Various types of interactions between halogen (X) and pi moiety (X-pi interaction) including halogen bonding play important roles in forming the structures of biological, supramolecular, and nanomaterial systems containing halogens and aromatic rings. Furthermore, halogen molecules such as X-2 and CX4 (X = Cl/Br) can be intercalated in graphite and bilayer graphene for doping and graphene functionalization/modification. Due to the X-pi interactions, though recently highly studied, their structures are still hardly predictable. Here, using the coupled-cluster with single, double, and noniterative triple excitations (CCSD(T)), the Moller-Plesset second-order perturbation theory (MP2), and various flavors of density functional theory (DFT) methods, we study complexes of benzene (Bz) with halogen-containing molecules X-2 and CX4 (X = Cl/Br) and analyze various components of the interaction energy using symmetry adapted perturbation theory (SAPT). As for the lowest energy conformers (S1), X-2-Bz is found to have the T-shaped structure where the electropositive X atom-end of X-2 is pointing to the electronegative midpoint of CC bond of the Bz ring, and CX4-Bz has the stacked structure. In addition to this CX4 Bz (S1), other low energy conformers of X-2-Bz (S2/S3) and CX4-Bz (S2) are stabilized primarily by the dispersion interaction, whereas the electrostatic interaction is substantial. Most of the density functionals show noticeable deviations from the CCSD(T) complete basis set (CBS) limit binding energies, especially in the case of strongly halogen-bonded conformers of X-2-Bz (S1), whereas the deviations are relatively small for CX4-Bz where the dispersion is more important. The halogen bond shows highly anisotropic electron density around halogen atoms and the DFT results are very sensitive to basis set. The unsatisfactory performance of many density functionals could be mainly due to less accurate exchange. This is evidenced from the good performance by the dispersion corrected hybrid and double hybrid functionals. B2GP-PLYP-D3 and PBE0-TS (Tkatchenko-Scheffler)/D3 are well suited to describe the X-pi interactions adequately, close to the CCSD(T)/CBS binding energies (within similar to 1 kJ/mol). This understanding would be useful to study diverse X-pi interaction driven structures such as halogen containing compounds intercalated between 2-dimensional layers.</P>

Impact of White Matter Changes on Activities of Daily Living in Mild to Moderate Dementia

Moon, So Young,Na, Duk L.,Seo, Sang Won,Lee, Jun-Young,Ku, Bon D.,Kim, Seong Yoon,Park, Kyung Won,Shim, Yong S.,Youn, Young Chul,Chung, Chan-Seung,Cheong, Hae-Kwan,Choi, Seong Hye,Cha, Kyung Ryeol,Kim S. Karger AG 2011 European neurology Vol.65 No.4

<P>The association between white matter changes and activities of daily living (ADL) in a large, well-defined cohort of patients with mild-to-moderate dementia (either Alzheimer’s disease or subcortical vascular dementia) were investigated. A total of 289 patients were divided into three groups (140 mild, 99 moderate, and 50 severe) depending on the degree of white matter changes as indicated on brain magnetic resonance image scans. Further, we analyzed the three groups’ performances on basic and instrumental ADL. The degree of white matter changes was associated with greater age, hypertension, previous history of stroke, higher Hachinski Ischemic Score, worse global cognitive and functional status, and an increased impairment of basic ADL and instrumental ADL. The increased impairment with regard to the severe group’s performance on both the basic and instrumental ADL remained significant after adjustment for age and hypertension. Tasks involving physical activities were most significant. This was the first study investigating the association between white matter changes and ADL in a large, well-defined dementia cohort. The present study suggests that severe white matter changes may be associated with higher impairment on both basic and instrumental ADL.</P><P>Copyright © 2010 S. Karger AG, Basel</P>

Universal Vector Driven Tester (VDT)

Seung Y. “Daniel” Lee,Byunghwan Chun,Brian Y. Kim,Austin S. Kim 한국통신학회 2006 한국통신학회 학술대회논문집 Vol.2006 No.7

Bismuth 의 전해 정련

이원해,고창식,이승평 대한금속재료학회(대한금속학회) 1971 대한금속·재료학회지 Vol.9 No.1

전해조는 가운데를 cell의 지면에는 닿지않고 Bi-amalgam에만 닿도록 격막으로 막은 두 개의 compartment로 되어 있어서 Bi-amalgam은 자유로이 다닐 수 있으나 전해액은 한쪽에서 다른쪽으로 다니지 못하게 하였다. stirrer로 교반하고 있는 Bi-amalgam의 한쪽은 anode로, 다른쪽은 cathode로 작용 하도록 하였다. refining solution으로 사용한 전해액의 성분은 Bi(ClO₄)와 HClO₄이며, Cathode전류 밀도는 5A-15A/d㎡가 가장 좋았고, 전류 효율은 100%였다. 98% Bi를 사용하여 amalgam refining을 해본 결과 5-9s보다 더 순수한 Bi를 얻을 수 있었다. The electrolytic apparatus was so made as a barrier was immersed in the shallow pool of Bi-amalgam without reaching the cell bottom. Therefore, the Bi-amalgam was permitted to pass freely, but the supernatant solution was not to. The amalgam, agitated with two stirrers, acted as cathode on one side and as anode on the other of the cell. The electrolytes consisting of Bi(ClO₄)₃ and HClO₄ was used as the refining solution. The recommendable cathode C.D. was 5A-15A/d㎡ and the current efficiency was 100%, The amalgam refining by using 98% Bi as anode resulted in obtaining ≥5-9s.

3D Lithography using X-ray Exposure Devices Integrated with Electrostatic and Electrothermal Actuators

Lee, Kwang-Cheol,Lee, Seung S. The Institute of Electronics and Information Engin 2002 Journal of semiconductor technology and science Vol.2 No.4

We present a novel 3D fabrication method with single X-ray process utilizing an X-ray mask in which a micro-actuator is integrated. An X-ray absorber is electroplated on the shuttle mass driven by the integrated micro-actuator during deep X-ray exposures. 3D microstructures are revealed by development kinetics and modulated in-depth dose distribution in resist, usually PMMA. Fabrication of X-ray masks with integrated electrothermal xy-stage and electrostatic actuator is presented along with discussions on PMMA development characteristics. Both devices use $20-\mu\textrm{m}$-thick overhanging single crystal Si as a structural material and fabricated using deep reactive ion etching of silicon-on-insulator wafer, phosphorous diffusion, gold electroplating, and bulk micromachining process. In electrostatic devices, $10-\mu\textrm{m}-thick$ gold absorber on $1mm{\times}1mm$ Si shuttle mass is supported by $10-\mu\textrm{m}-wide$, 1-mm-long suspension beams and oscillated by comb electrodes during X-ray exposures. In electrothermal devices, gold absorber on 1.42 mm diameter shuttle mass is oscillated in x and y directions sequentially by thermal expansion caused by joule heating of the corresponding bent beam actuators. The fundamental frequency and amplitude of the electrostatic devices are around 3.6 kHz and $20\mu\textrm{m}$, respectively, for a dc bias of 100 V and an ac bias of 20 VP-P (peak-peak). Displacements in x and y directions of the electrothermal devices are both around $20{\;}\mu\textrm{m}$at 742 mW input power. S-shaped and conical shaped PMMA microstructures are demonstrated through X-ray experiments with the fabricated devices.

Collateral projection from the locus coeruleus to whisker-related sensory and motor brain regions of the rat

Lee, Sat-Byol,Beak, Suk K.,Park, Seung H.,Waterhouse, Barry D.,Lee, Hyun S. Wiley Subscription Services, Inc., A Wiley Company 2009 Journal of comparative neurology Vol.514 No.4

<P>The primary goal of this study was to examine whether the locus coeruleus (LC) provides collateral projections to whisker-related, sensorimotor brain regions. After injections of retrograde tracers into the primary sensory (S1) barrel field/primary whisker motor (M1) cortices, ventroposteromedial (VPM)/ventrolateral (VL) thalamic nuclei, or principal sensory trigeminal (Pr5)/facial motor (Mo7) nuclei, the distribution of double-labeled neurons within the LC was examined. Our observations indicated that a large number of individual LC cells provided axon collaterals to S1-M1 or VPM-VL regions, whereas only a few projected to Pr5-Mo7 nuclei. The laterality and the distribution of dual-projecting LC neurons were as follows. 1) The neurons projecting to the S1-M1 cortices were predominantly ipsilateral (96% ± 0.7%). Labeled neurons were located ventrally at the rostral pole but were evenly distributed along the dorsoventral aspect of the principal LC. 2) The cells projecting to the VPM-VL nuclei were bilateral, with ipsilateral (68% ± 2.3%) dominance. Neurons were observed at the rostrocaudal extent of the LC, where the labeling was most pronounced at the ventral, principal LC. 3) The neurons projecting to the Pr5-Mo7 regions exhibited slightly contralateral (56% ± 2.9%) dominance, where labeled cells were confined within the ventral margin of the principal subdivision. Taken together, the present observations demonstrate that each subdivision of the LC possesses a differential functional organization with respect to its collateral projection to whisker-related sensorimotor targets, suggesting that the nucleus might play a modulatory role in vibrissal sensorimotor integration that allows the guidance of behavioral action essential for the survival of the animal. J. Comp. Neurol. 514:387–402, 2009. © 2009 Wiley-Liss, Inc.</P>

Synchronized Oxygen Delivery and Its Optimization Method: A Bench Study

Lee, Gil Jun,Cha, Seung Keun,Oh, Seung Kwon,Shin, Choongsoo S.,Lee, Tae Soo Korean Society for Precision Engineering 2013 International Journal of Precision Engineering and Vol.14 No.4

Long-term oxygen therapy (LTOT) has been widely used to treat patients with chronic obstructive pulmonary disease. The traditional oxygen delivery methods used for LTOT are continuous flow oxygen (CFO) and demand oxygen delivery (DOD). CFO wastes a considerable amount of oxygen, whereas DOD often makes patients feel uncomfortable because it abruptly supplies a large amount of oxygen at the onset of inhalation. Hence, we developed an algorithm for predicting the onset of inhalation, which allowed oxygen to be supplied smoothly before inhalation. Moreover, we minimized the discomfort index (DI) to offer more comfortable oxygen delivery. By integrating the prediction algorithm and the minimization of DI, the previous synchronized demand oxygen delivery (SDOD) method was modified. We constructed a bench model to validate the modified SDOD. The results showed that the proposed algorithm accurately predicted the onset of inhalation. The difference in the real-time measured and predicted values for the beginning of inhalation was less than 0.10 s. Using the proposed minimization technique, the DI was decreased by 50% under 20 breaths per minute when compared with the DI calculated from a previous study. In conclusion, the modified SDOD could supply oxygen more comfortably while synchronizing with patient breathing patterns.

혈액 투석 환자에서 중심정맥 협착에 대한 스텐트 삽입술 : Wallstent Placement

임대승,노상필,이유선,정승현,김보영,이정우,강정아,김정희,이민수,정준용,최시완,정진옥,성인환,이강욱,신영태 충남대학교 의과대학 의학연구소 2002 충남의대잡지 Vol.29 No.1

Stenosis of central vein is a common complication arising after percutaneous subclavian vein catheter insertion performed for temporary vascular access in chronic renal failure patients undergoing hemodialysis. There are several treatment methods for the condition like percutaneous angioplasty(PTA), stent insertion, and surgery, but recent trend is toward PTA and stents. Among the patients diagnosed with chronic renal failure from March 1993 to May 2002 and undergoing hemodialysis through AV fistula, the 14 Patients in whom central vein stenosis arose were selected for the study. A total of 28 percutaneous interventions(5 PTA and 23 stent placement) were performed, and restenosis rate and the time taken till the restenosis in de novo lesions and instant lesions were compared. All 28 cases were operated successfully. The 14 cases that received both anigioplasty and stent placement initially. (de novo lesion : 14 cases), Among the 10 cases with de novo lesion that followed up more than 1 year, 3 cases are currently undergoing hemodialysis without restenosis, and the remaining 7 cases have recurred stenosis with the mean time to restenosis of 10.9 months. In the 7 cases in whom stenosis recurred, 11 interventions were done(instent lesion: 11 cases). 4 of these were using only ballon angioplasty with 100% restenosis rate and the mean time of 3 months until restenosis. The remaining 7 cases were using both balloon angioplasty and stent placement, also with 100% restenosis rate but with the mean time of 12 months until restenosis, which was later than the group receiving only balloon angioplasty. In treating the patients with central vein stenosis, stent placement seems to be more advantageous over PTA in terms of restenosis rate and the mean duration of patency. In the case of instent lesion, inserting the stent for the second time after stenosis recurred lengthened the duration of patency compared to performing balloon angioplasty alone.

白鼠 子宮組織內 窒素및 核酸含量 變動에 關한 硏究

吳承浩,李碩雨 우석대학교 의과대학 1969 우석의대잡지 Vol.6 No.1

This study were measured for observation of the variations of the content of nitrogen, DNA and RNA in uterus of the Wister Institute Albino Rat during feeding diets mixed with dried smallsardine flour and rice. The experimental animals were divided into five groups; the control (S), the feeding mixed diet every other day (Ⅰ), two days (Ⅱ), three days (Ⅲ) and four days group (Ⅳ). The results were summarized as follows: 1. In the nitrogen content of the rat's uterus, being compared with (S) group, (Ⅰ) group showed a distinct decrease on the 30th day after feeding, but did not change significantly on the 60th day and (Ⅱ) and (Ⅲ) groups showed a slight decrease, but (Ⅳ) group showed the most outstanding decrease of all the groups on the 60th day. 2. In the DNA content of the rat's uterus, being compared with (S) group, (Ⅰ) group showed a distinct decrease on the 15th to 45th day after feeding, and did not change markedly on the 60th day. However, (Ⅳ) group showed the most significant decrease of all the groups on the 60th day. 3. In the RNA content of the rat's uterus, compared with (S) group, (Ⅰ) group showed a slight increase on the 30th to 45th day after feeding, and a slight decrease on the 60th day. But there was no significant difference in (Ⅱ), (Ⅲ) and (Ⅳ) groups after feeding, being compared with (S) group.

전기자극처리와 천연항균성물질의 육표면처리가 한우육의 저장성에 미치는 효과

김수민,이신호,임용숙,김대곤,성삼경,박경남 한국축산학회 1999 한국축산학회지 Vol.41 No.4

Effects of electrical stimulation(550V, 90 sec) and medicinal herbs on shelf life of vacuum packaged Hanwoo beef at 0℃ were examined. pH and volatile basic nitrogen (VBN) did not show significant difference among treatments and decreased rapidly after 70 days of storage. Hardness of electrical stimulated Hanwoo beef was lower than that of control but did not show significant difference between electrical stimulated beef and medicinal herbs treated beef. Lightness of electrical stiumlated beef was higher than that of untreated beef. The color of each treatments did not change significantly during storage. Pinus densiflona (PD) spray, PD and Lithospermum erythrorhizon(LE) spray and electrical stimulations significantly reduced the total bacteria and psychrotrophs compared to control and produced a 1 log cycle reduction in both bacteria. Viable cell of these bacteria was inhibited apparently during storage. Self life of vacuum packaged Hanwoo beef with electrical stimulation was improved by spary of PD and LE on surface of Hanwoo beef.