• Journal of Korean Neurosurgical Society
• /
• 제50권2호
• /
• pp.89-94
• /
• 2011

Objective : D-dimer is a breakdown product of fibrin mesh after factor XIII stabilization. Previously, many authors have demonstrated a relationship between D-dimer level and stroke progression or type. This study aimed to investigate the relationship between D-dimer level and stroke volume. Methods : Between January 2008 and December 2009, we analyzed the D-dimer levels of 59 acute ischemic stroke patients in our neurosurgical department both upon admission and after seven days of initial treatment. Each patient's National Institute of Health Stroke Scale score, modified Rankin Scales score, Glasgow outcome score, and infarction volume were also evaluated. Results : Mean D-dimer level at admission was 626.6 ${\mu}g/L$ (range, 77-4,752 ${\mu}g/L$) and the mean level measured after seven days of treatment was 238.3 ${\mu}g/L$ (range, 50-924 ${\mu}g/L$). Mean D-dimer level at admission was 215.3 ${\mu}g/L$ in patients with focal infarctions, 385.7 ${\mu}g/L$ in patients with multiple embolic infarctions, 566.2 ${\mu}g/L$ in those with 1-19 cc infarctions, 668.8 ${\mu}g/L$ in 20-49 cc infarctions, 702.5 ${\mu}g/L$ in 50-199 cc infarctions, and 844.0 ${\mu}g/L$ in >200 cc infarctions (p=0.044). On the 7th day of treatment, the D-dimer levels had fallen to 201.0 ${\mu}g/L$, 293.2 ${\mu}g/L$, 272.0 ${\mu}g/L$, 232.8 ${\mu}g/L$, 336.6 ${\mu}g/L$, and 180.0 ${\mu}g/L$, respectively (p=0.530). Conclusion : Our study shows that D-dimer level has the positive correlation with infarction volume and can be use to predict infarction-volume.

• Journal of Hospice and Palliative Care
• /
• 제23권1호
• /
• pp.11-16
• /
• 2020

Purpose: D-dimer levels are known to be associated with poor outcomes in patients with various cancers, but their significance at the end of life remains unclear. This study investigated D-dimer levels as a prognostic indicator for terminal cancer patients in the last hours of life. Methods: The retrospective study was conducted at a palliative care unit of a tertiary cancer center, using a database to analyze the records of patients treated from January 1, 2010 to December 31, 2018. In total, 67 terminal cancer patients with available data on D-dimer levels were included. Patients' demographic data, clinical information, and laboratory values, including D-dimer levels, were collected. Survival was analyzed using the Kaplan-Meier method and the log-rank test. A Cox proportional-hazards model was used to identify prognostic factors of poor survival. Results: The most common site of cancer was the lung (32.8%) and the median survival time was 5 days. Most laboratory results, particularly D-dimer levels, deviated from the normal range. Patients with high D-dimer levels had a significantly shorter survival time than those with low D-dimer levels (4 days vs. 7 days; P=0.012). In the Cox regression analysis, only a high D-dimer level was identified as a predictor of a poor prognosis (hazard ratio, 1.83; 95% confidence interval, 1.09~3.07). Conclusion: Our results suggest that at the very end of life, D-dimer levels may serve as a prognostic factor for survival in cancer patients.

• Biomolecules & Therapeutics
• /
• 제2권1호
• /
• pp.28-33
• /
• 1994

In order to obtain insight into the repair mechanism of DNA containing thymine photo-dimer, the conformation of the duplex d(GCGGTTGGCG).d(CGCCAACCGC) with a thymine dimer incorporated has been studied by proton NMR. NOE data show that, although the local environment around the thymine dimer is altered, the gross structural changes are relatively small. T$_4$endonuclease V exhibited a conformational change on complex formation with DNA. This conformational change occurred around histidine 16 which was close to tyrosine 129 located in the aromatic segment (WYKYY) near the C-terminus. It is likely that the interaction between T$_4$endonuclease V and DNA is strong since the complex was not dissociated up to 1.6 M NaCl.

• 분석과학
• /
• 제20권2호
• /
• pp.124-130
• /
• 2007

In this study, we present the preparation and characterization of oxidized fullerene and fullerene dimer [$C_{120}$]. From the XRD data, other weak peaks with pristine fullerene [$C_{60}$] peaks were observed in the X-ray diffraction patterns for fullerene dimer [$C_{120}$]. SEM micrographs for the fullerene dimer [$C_{120}$] indicated that practically all the surface state was shown the drastic morphology changes and its outer surface is clearly visible and resulted in clogging and frost-like formation. From the MALDI-TOF mass spectra, the differences in the spectra recorded on two kinds of fullerene are due to the oxidation including chemical bonding and bridging between the $C_{60}$ molecules. We also obtained additional information from FT-IR spectra on functional component on the chemically modified surface of oxidized fullerene and fullerene dimer [$C_{120}$].

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권4호
• /
• pp.1655-1658
• /
• 2014

Objective: To find a more appropriate alternative to D-dimer cutoff value for the diagnosis of deep vein thrombosis (DVT) in cancer patients. Methods: A total of 711 cancer patients with symptoms suspicious of DVT were included in the study. D-dimer levels were assessed using ELISA. All patients were subjected to imaging procedures. Results: Among 711 patients with cancer, 466 (65.5%) were females and 245 (34.5%) were males, with an average age of $57.3{\pm}13.23$ years. The mean age in the DVT group was significantly higher than in the non-DVT group (P<0.05). The D-dimer levels of the DVT group were significantly higher than those of the non-DVT group (P<0.05). The incidence rate of DVT varied significantly according to cancer type (P<0.05). Increasing age and lung cancer were significantly correlated with D-dimer levels (P<0.05), and a one-year increase in age was associated with a 14.28 ng/ml increase in the D-dimer value. The optimal cutoff point for D-dimer was found to be 981 ng/ml, with a sensitivity of 86.4%, specificity of 79.4%, and accuracy of 82.6%. If the D-dimer cutoff point was set to 981ng/ml, the specificity would increase from 61.8% to 85.5% without loss of sensitivity in patients aged 40 years or younger. In patients aged more than 40 years, the new cutoff almost doubled the specificity with slightly reduced sensitivity. Conclusion: In cancer patients, a new cutoff value of 981 ng/ml effectively improved the exclusion of DVT, especially for patients aged more than 40 years.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
• /
• pp.184-184
• /
• 2011

Using first-principles density-functional calculations, we investigate the chain reaction mechanism of allyl alcohol (ALA) molecules on the H-terminated Si(001)-2${\times}$1 surface. Recently, it was reported [1] that allyl mercaptan (ALM) molecules show a self-directed line growth across the dimer rows through a chain reaction involving several reaction processes: (i) The created radical at the C atom is transferred to the S atom, (ii) the resulting S-centered radical easily abstracts an H atom from the neighboring dimer row, and (iii) the generated S-H group further reacts with the neighboring dimer row to produce the Si-S bond on the neighboring dimer row, accompanying the associative desorption of H2. This H2-desorption process creates a new DB on the neighboring dimer row, setting off the chain reaction across the dimer rows. In the present study, we find that although the structure of ALA with -OH functional is analogous to that of ALM with -SH functional, ALA and ALM lines show a difference in their growth direction. We predict that ALA undergoes the chain reaction to show a line growth along the dimer row, contrasting with the ALM line growth across the Si dimer rows. Our analysis shows that the different growth direction of ALA is due to the strong instability of oxygen radical intermediate, which prevents from growing across the dimer rows. Thus, we demonstrate that the stability of the radical intermediate plays a crucial role in determining the direction of molecular line growth.

• Tuberculosis and Respiratory Diseases
• /
• 제68권2호
• /
• pp.87-92
• /
• 2010

Background: D-dimer testing is widely applied as a first step in the diagnostic work-up of pulmonary embolism (PE). Although this is the most sensitive assay for ruling out PE, the prognostic implications of D-dimer testing in patients with normotensive PE are not well known. The aim of this study was to determine if D-dimer testing on admission predicts major adverse cardiac events (MACE) in patients with normotensive PE. Methods: A total of 180 consecutive patients with normotensive PE admitted between January 2003 and June 2009 were included. The group was divided into quartiles on the basis of their D-dimer levels. We compared the frequency of MACE by quartile of D-dimer level and estimated sensitivity, specificity, and predictive values for MACE in the first and fourth quartile. Results: In the 37 (20.6%) patients with MACEs, the median D-dimer level (7.94[IQR:4.03~18.17]${\mu}g/mL$) was higher than in patients with a benign course (5.29[IQR:2.60~11.52]${\mu}g/mL$, p<0.01). The occurrence of MACEs was increased with increasing D-dimer level (p=0.017). In the first quartile (D-Dimer <$2.76{\mu}g/mL$) sensitivity, specificity, and positive and negative predictive values for predicting MACEs were, respectively, 91.9%, 29.4%, 25.2%, and 93.3%. Conclusion: Patients with D-dimer levels below $2.76{\mu}g/mL$ have a low risk of MACEs. Our study suggest that D-dimer level may be used to identify low risk patients with normotensive PE.

• Bulletin of the Korean Chemical Society
• /
• 제17권6호
• /
• pp.525-528
• /
• 1996

Seven cali[4]arenes, having two different substituents in AAAB or AABB pattern at the upper rim of calix were synthesized by fragmentation condensation reaction of p-substituted phenol trimer (AAA) with 2,6-bishydroxymethylated 4-substituted phenol (B) or that of dimer (AA) with 2,2'-bishydroxymethylated dimer (BB). An equimolar mixture of the coupling components (trimer and monomer or dimer and dimer) was refluxed in dioxane in the presence of TiCl4to afford calix[4]arene 6 and 7 in 15-38% yield. The structure of calix[4]arenes was confirmed by elemental analysis and the 1H/13C NMR spectroscopy.

• 한국진공학회지
• /
• 제15권2호
• /
• pp.152-161
• /
• 2006

일차원의 대칭성을 갖는 형판 위에서 Bi원자가 자발적으로 형성하는 나노 구조체의 원자 구조를 이해하기 위하여, 재구조 된 Si(5 5 12)을 Bi의 탈착 온도에 가까운 온도로 가열한 채 Bi를 흡착시키고 주사 터널링 현미경으로 그 원자 구조를 각 흡착 단계별로 규명하였다. 제일 먼저 Bi는 이 기판에 존재하는 여러 종류의 $[\bar{1}\;1\;0]$에 평행한 row들 중에서 기판과 결합력이 가장 약한 dimer row와 adatom row 만을 선택적으로 Bi-dimer row와 Bi-adatom row로 각각 치환한다. 이 과정에서 치환된 Bi는 Si과의 크기 차이로 인해 인접한 (337) subsection에 tensile stress를 인가하게 되고, 그 결과 (337) subsection 내의 tetramer row는 갈라져 dimer row와 adatom row로 변형되고, 이들 역시 Bi-dimer row와 Bi-adatom row로 각각 치환된다. 다음으로 이들 치환된 Bi-dimer row와 Bi-adatom row 위에 각각 Bi-dimer가 흡착하면 서로 마주보며 안정된 Bi-dimer pair를 이루며, 이 pair 역시 row를 이루고 둘째 층을 형성한다. 마지막으로 셋째 층의 Bi는 둘째 층의 마주보는 Bi-dimer pair 위에 흡착한 한 개의 Bi-dime이며 더 이상의 Bi는 쌓이지 않는다. 이와 같이 자발적으로 조립되는 Bi-dimer row의 형성 원인을 종합하면, 재구조 된 Si(5 5 12) 위에서 Bi의 선택적 반응, Bi와 Si의 크기 차이로 인한 표면 stress의 유발, Bi 원자 간의 안정된 결합형태 등을 들 수 있다.

• 한국식품과학회지
• /
• 제32권6호
• /
• pp.1234-1243
• /
• 2000

Polystyrene 재질 용기 내에 함유된 내분비계 장애추정물질인 styrene dimer 및 trimer의 분석 방법과 컵라면 및 요구르트 용기로부터 식품으로 이행된 량을 정량하는 방법을 연구하였다. 재질 중 styrene dimer와 trimer의 함량은 재질을 tetrahydrofuran에 완전히 용해시킨 후, n-hexane을 이용하여 고분자량체 만을 석출시켜 제거함으로써 효과적으로 분석할 수 있었다. 식품분석은 GC/MS SIM-mode를 이용함으로써 $3.2{\sim}87\;ppb$ 수준의 미량 분석이 가능하였다. 라면시료 중의 지방제거 과정으로는 flrorisil 방법만에서 80% 정도의 높은 회수율을 나타내었고, hexane 포화 acetonitrile 분배 과정을 거치면서 상당히 감소하였다. 그러나 요구르트의 경우, 전처리 과정 없이 추출 후 곧바로 분석이 가능하였다. 추출 용매로는 라면에 대하여는 acetone/hexane(1:1)용액이 80% 정도의 가장 높은 회수율을 보였으며, 요구르트에 대하여는 aceton/hexane(1:1)뿐만 아니라, dichloromethane, ether등에서 비슷한 회수율이 얻어졌다.