A Low-Cost and Low-Power Time-to-Digital Converter Using Triple-Slope Time Stretching

Manho Kim,Hyunjoong Lee,Jong-Kwan Woo,Nan Xing,Min-Oh Kim,Suhwan Kim IEEE 2011 IEEE transactions on circuits and systems. a publi Vol.58 No.3

<P>In this brief, we present a time-to-digital converter (TDC) in which a single interpolator is used to improve the resolution by time stretching. The interpolator is based on a triple-slope conversion. Without slowing down the measured event, this approach extensively reduces the chip area and the corresponding power consumption, as compared with the prior arts with two parallel time interpolators. A prototype was designed and fabricated in a 0.35- μm CMOS digital process, and its core area merely occupies 0.126 mm<SUP>2</SUP>. Measurements show that our TDC achieves a resolution of 357 ps while consuming 1.22 mW with a 2.5-V supply. The dynamic range of the TDC exceeds 1.46 μs. The measurement rate can achieve above 400 kS/s.</P>

Primary Diffuse Leptomeningeal Gliomatosis: Report of a Case Presenting with Chronic Meningitis

Kim, Sung-Hun,Jun, Dong-Chul,Park, Jin Se,Heo, Jae-Hyeok,Kim, Sung-Min,Kim, Juhan,Paek, Sun Ha,Kim, Manho Korean Neurological Association 2006 Journal of Clinical Neurology Vol.2 No.3

<P>Neoplastic meningitis occurs in approximately 5% of patients with cancer. Primary diffuse leptomeningeal gliomatosis is a rare condition whereby a glioma arises from heterotopic cell nests in the leptomeninges. We report here a case presenting with clinical features similar to those of chronic infectious meningitis without positive cerebrospinal fluid cytology. Neurological signs in our patient deteriorated progressively without responding to antitubercular, antiviral, or antibiotic therapy. Leptomeningeal biopsy sampling revealed the condition to be primary diffuse leptomeningeal gliomatosis.</P>

Panax ginseng as an adjuvant treatment for Alzheimer's disease

Kim, Hyeon-Joong,Jung, Seok-Won,Kim, Seog-Young,Cho, Ik-Hyun,Kim, Hyoung-Chun,Rhim, Hyewhon,Kim, Manho,Nah, Seung-Yeol The Korean Society of Ginseng 2018 Journal of Ginseng Research Vol.42 No.4

Longevity in medicine can be defined as a long life without mental or physical deficits. This can be prevented by Alzheimer's disease (AD). Current conventional AD treatments only alleviate the symptoms without reversing AD progression. Recent studies demonstrated that Panax ginseng extract improves AD symptoms in patients with AD, and the two main components of ginseng might contribute to AD amelioration. Ginsenosides show various AD-related neuroprotective effects. Gintonin is a newly identified ginseng constituent that contains lysophosphatidic acids and attenuates AD-related brain neuropathies. Ginsenosides decrease amyloid ${\beta}$-protein ($A{\beta}$) formation by inhibiting ${\beta}$- and ${\gamma}$-secretase activity or by activating the nonamyloidogenic pathway, inhibit acetylcholinesterase activity and $A{\beta}$-induced neurotoxicity, and decrease $A{\beta}$-induced production of reactive oxygen species and neuro-inflammatory reactions. Oral administration of ginsenosides increases the expression levels of enzymes involved in acetylcholine synthesis in the brain and alleviates $A{\beta}$-induced cholinergic deficits in AD models. Similarly, gintonin inhibits $A{\beta}$-induced neurotoxicity and activates the nonamyloidogenic pathway to reduce $A{\beta}$ formation and to increase acetylcholine and choline acetyltransferase expression in the brain through lysophosphatidic acid receptors. Oral administration of gintonin attenuates brain amyloid plaque deposits, boosting hippocampal cholinergic systems and neurogenesis, thereby ameliorating learning and memory impairments. It also improves cognitive functions in patients with AD. Ginsenosides and gintonin attenuate AD-related neuropathology through multiple routes. This review focuses research demonstrating that ginseng constituents could be a candidate as an adjuvant for AD treatment. However, clinical investigations including efficacy and tolerability analyses may be necessary for the clinical acceptance of ginseng components in combination with conventional AD drugs.

Role of GSK-3β activity in motor neuronal cell death induced by G93A or A4V mutant hSOD1 gene : Role of GSK-3β in motoneuron disease

Koh, Seong-Ho,Lee, Young-Bae,Kim, Kyung S.,Kim, Hyun-Jung,Kim, Manho,Lee, Young Joo,Kim, Juhan,Lee, Kwang Woo,Kim, Seung Hyun Wiley (Blackwell Publishing) 2005 The European journal of neuroscience Vol.22 No.2

<P>Point mutations such as G93A and A4V in the human Cu/Zn-superoxide dismutase gene (hSOD1) cause familial amyotrophic lateral sclerosis (fALS). In spite of several theories to explain the pathogenic mechanisms, the mechanism remains largely unclear. Increased activity of glycogen synthase kinase-3 (GSK-3) has recently been emphasized as an important pathogenic mechanism of neurodegenerative diseases, including Alzheimer's disease and ALS. To investigate the effects of G93A or A4V mutations on the phosphatidylinositol-3-kinase (PI3-K)/Akt and GSK-3 pathway as well as the caspase-3 pathway, VSC4.1 motoneuron cells were transfected with G93A- or A4V-mutant types of hSOD1 (G93A and A4V cells, respectively) and, 24 h after neuronal differentiation, their viability and intracellular signals, including PI3-K/Akt, GSK-3, heat shock transcription factor-1 (HSTF-1), cytochrome c, caspase-3 and poly(ADP-ribose) polymerase (PARP), were compared with those of wild type (wild cells). Furthermore, to elucidate the role of the GSK-3beta-mediated cell death mechanism, alterations of viability and intracellular signals in those mutant motoneurons were investigated after treating the cells with GSK-3beta inhibitor. Compared with wild cells, viability was greatly reduced in the G93A and A4V cells. However, the treatment of G93A and A4V cells with GSK-3beta inhibitor increased their viability by activating HSTF-1 and by reducing cytochrome c release, caspase-3 activation and PARP cleavage. However, the treatment did not affect the expression of PI3-K/Akt and GSK-3beta. These results suggest that the G93A or A4V mutations inhibit PI3-K/Akt and activate GSK-3beta and caspase-3, thus becoming vulnerable to oxidative stress, and that the GSK-3beta-mediated cell death mechanism is important in G93A and A4V cell death.</P>

Anti-inflammatory mechanism of intravascular neural stem cell transplantation in haemorrhagic stroke.

Lee, Soon-Tae,Chu, Kon,Jung, Keun-Hwa,Kim, Se-Jeong,Kim, Dong-Hyun,Kang, Kyung-Mook,Hong, Nan Hyung,Kim, Jin-Hee,Ban, Jae-Joon,Park, Hee-Kwon,Kim, Seung U,Park, Chung-Gyu,Lee, Sang Kun,Kim, Manho,Roh, Macmillan ; Oxford University Press 2008 Brain Vol.131 No.3

<P>Neural stem cell (NSC) transplantation has been investigated as a means to reconstitute the damaged brain after stroke. In this study, however, we investigated the effect on acute cerebral and peripheral inflammation after intracerebral haemorrhage (ICH). NSCs (H1 clone) from fetal human brain were injected intravenously (NSCs-iv, 5 million cells) or intracerebrally (NSCs-ic, 1 million cells) at 2 or 24 h after collagenase-induced ICH in a rat model. Only NSCs-iv-2 h resulted in fewer initial neurologic deteriorations and reduced brain oedema formation, inflammatory infiltrations (OX-42, myeloperoxidase) and apoptosis (activated caspase-3, TUNEL) compared to the vehicle-injected control animals. Rat neurosphere-iv-2 h, but not human fibroblast-iv-2 h, also reduced the brain oedema and the initial neurologic deficits. Human NSCs-iv-2 h also attenuated both cerebral and splenic activations of tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and nuclear factor-kappa B (NF-kappaB). However, we observed only a few stem cells in brain sections of the NSCs-iv-2 h group; in the main, they were detected in marginal zone of spleens. To investigate whether NSCs interact with spleen to reduce cerebral inflammation, we performed a splenectomy prior to ICH induction, which eliminated the effect of NSCs-iv-2 h transplantation on brain water content and inflammatory infiltrations. NSCs also inhibited in vitro macrophage activations after lipopolysaccharide stimulation in a cell-to-cell contact dependent manner. In summary, early intravenous NSC injection displayed anti-inflammatory functionality that promoted neuroprotection, mainly by interrupting splenic inflammatory responses after ICH.</P>

Stem cell-based cell therapy for Huntington disease: A review

Kim, Manho,Lee, Soon-Tae,Chu, Kon,Kim, Seung U. Blackwell Publishing Asia 2008 NEUROPATHOLOGY Vol.28 No.1

<P>Huntington disease (HD) is a devastating neurodegenerative disorder and no proven medical therapy is currently available to mitigate its clinical manifestations. Although fetal neural transplantation has been tried in both preclinical and clinical investigations, the efficacy is not satisfactory. With the recent explosive progress of stem cell biology, application of stem cell-based therapy in HD is an exciting prospect. Three kinds of stem cells, embryonic stem cells, bone marrow mesenchymal stem cells and neural stem cells, have previously been utilized in cell therapy in animal models of neurological disorders. However, neural stem cells were preferably used by investigators in experimental HD studies, since they have a clear capacity to become neurons or glial cells after intracerebral or intravenous transplantation, and they induce functional recovery. In this review, we summarize the current state of cell therapy utilizing stem cells in experimental HD animal models, and discuss the future considerations for developing new therapeutic strategies using neural stem cells.</P>

Excited-state energy relaxation dynamics of triply linked Zn(<small>II</small>) porphyrin arrays

Kim, Pyosang,Ikeda, Toshiaki,Lim, Jong Min,Park, Jaeheung,Lim, Manho,Aratani, Naoki,Osuka, Atsuhiro,Kim, Dongho Royal Society of Chemistry 2011 Chemical communications Vol.47 No.15

<P>In this study, we have investigated the excited-state energy deactivation dynamics of extended π-conjugated molecular systems that consist of competitive electronic and vibrational relaxation processes.</P> <P>Graphic Abstract</P><P>We have investigated the excited-state energy deactivation dynamics of extended π-conjugated molecular systems that consist of competitive electronic and vibrational relaxation dynamics. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1cc10521c'> </P>

Effects of Cross-Linking and Spacer Groups on beta-Cyclodextrin Bonded Liquid Chromatographic Separation

Kim, Manhoe,Way, J. Douglas,Baldwin, Robert M. 한국화학공학회 2004 Korean Journal of Chemical Engineering Vol.21 No.2

Mesoporous glass beads and 5um silica particles were modified with beta-cyclodextrin(β-CD)by means of directly bonding, linking spacer group, and cross-linking agent. The selectivities of the β-CD modified silica particles were measured by simple column chromatography to separate a model mixture of 1-and 2-hydroxy-naphthalene(naphthols)and ortho, meta, and para-xylene. In the packed column chromatography experiments, two major controlling factors(inclusion complex formation effect and steric hindrance effect of the analytes)on the separations were observed. The elusion orders of the β-CD directly bonded glass beads were meta-, para-, ortho-xylene and 1-naphthol,2-naphthol. The phenomena of β-CD pore blocking and narrowing by spacer groups and cross-linking agent were observed. The spacer group and cross-linking agent decreased inclusion complex formation of 2-naphthol.

Lack of association between C3435T nucleotide MDR1 genetic polymorphism and multidrug-resistant epilepsy

Kim, Dong Wook,Kim, Manho,Lee, Sang Kun,Kang, Rami,Lee, Seo-Young Elsevier 2006 SEIZURE Vol.15 No.5

<P><B>Summary</B></P><P>The variability of P-glycoprotein expression in individuals is linked to a C3435T polymorphism of the multidrug-resistance 1 (MDR1) gene, and the CC genotype at the C3435T polymorphism was reported to be associated with multidrug resistance in epilepsy patients. Since population frequencies of polymorphic genes depend on ethnic specificity, we investigated functional significance of the C3435T polymorphism of the MDR1 gene in Korean epilepsy patients. One hundred and eight patients with drug-responsive epilepsy, 63 patients with drug-resistant epilepsy, and 219 control migraine subjects were studied, but the analysis for C3435T allele showed no significant association between the CC genotype and the multidrug-resistant epilepsy. We suggest that influence of the C3435T polymorphism in the multidrug-resistant epilepsy may not be significant in Korean populations and further investigations in various ethnic populations would be necessary to clarify the effect of C3435T polymorphism on the mutidrug resistance in epilepsy patients.</P>

Electroacupuncture enhances motor recovery performance with brain-derived neurotrophic factor expression in rats with cerebral infarction.

Kim, Min-Wook,Chung, You Chul,Jung, Hee Chan,Park, Moon-Seo,Han, Young-Min,Chung, Yong-An,Maeng, Lee-So,Park, Sang-In,Lim, Jiyeon,Im, Woo-Seok,Chung, Jin Young,Kim, Minky,Mook, Inhee,Kim, Manho The Society 2012 ACUPUNCTURE IN MEDICINE Vol.30 No.3

<P>Electroacupuncture (EA) is a traditional medicine in patients with post-stroke rehabilitation. Brain-derived neurotrophic factor (BDNF) is a potent growth factor involved in recovery following cerebral injury. The aim of the present study was to investigate whether EA increases BDNF levels and facilitates functional recovery.</P>