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91.
The effect of acidic fluoride solution on NiTi arch wires was examined by testing crystal structure, tensile strength, morphology after fracture, and element release from wire under four different test solutions after 1 or 3 d immersion. Three-day immersion in a 0.2%/pH 4 solution did not form any new crystal structure. However, tensile strength after immersion was changed compared to the as-received wires. 3M wires showed increased tensile strength whereas G&H and Ormco wires showed decreased strength. Significant difference in tensile strength was associated with the immersion period. The fractured wires showed dimple patterns in the inner part of the wire, and ductile features on the outer part. Element release in the test solution increased as NaF concentration and the period of immersion increased, and as pH valued decreased. Wires immersed in a 0.2%/pH 4 solution released several-fold greater amount of elements than wires in a 0.05%/pH 4 solution. Tensile strength and element release were affected by acidic fluoride solution. In particular, NaF concentration, pH value, and the period of immersion were the factors affecting these properties. 相似文献
92.
Kang MJ Kim JH Lee SK Kang W Kim HS Lyoo WS Jeong TC 《Archives of pharmacal research》2010,33(11):1797-1803
Tetrabromobisphenol A (TBBPA), one of the most widely used brominated flame retardants in the world, is used to improve fire
safety of laminates in electrical and electronic equipment. A liquid chromatography-tandem mass spectrometry was developed
for the determination of TBBPA in rat serum and urine, and applied to the toxicokinetic study of TBBPA in rats. Acceptable
linearity was observed over the concentration ranges of 0.25–50 and 0.01–5 μg/mL in serum and urine, respectively. The limits
of detection of TBBPA were 0.04 μg/mL in serum, and 0.0025 μg/mL in urine. The precisions for the assay in serum and urine
were below 13 and 14%, respectively, and the accuracies ranged 95–111% and 98–101% for intraday and 97–107% and 97–102% for
inter-day, respectively. Serum and urine concentrations of TBBPA were successfully monitored following oral administrations
at the dose of 200 mg/kg in male Sprague Dawley rats. Toxic signs were not observed at 200 mg/kg of TBBPA. The present results
suggest that the rapid method developed in the present study affords sensitivity, accuracy and precision necessary for quantitative
measurements in toxicokinetic studies of TBBPA in vivo. 相似文献
93.
94.
Cheon JE Kim WS Kim IO Kim SH Yeon KM Ha IS Cheong HI Choi Y 《Pediatric radiology》2006,36(7):682-686
Background: Nutcracker syndrome is characterized by gross haematuria caused by left renal vein (LRV) entrapment. Objective: To assess the role of LRV ultrasonography in the diagnosis of the nutcracker syndrome in children. Materials and methods: Twelve children (eight male, four female; mean age 12.8 years) with venographically confirmed nutcracker syndrome (LRV-IVC pressure gradient ≥3 mm Hg) underwent LRV sonography including Doppler spectral analysis (n=7). The diameter and peak velocity (PV) were measured at two sites of the LRV (renal hilum and aortomesenteric portion). The US findings of nutcracker syndrome were compared with those of 20 control subjects using the t-test. We identified the optimal cut-off value of the US parameters for the diagnosis of the nutcracker syndrome using ROC analysis. Results: The PV at the aortomesenteric portion and the ratio of the PV between the two measured points showed significant differences between the two groups (P<0.0001). The optimum cut-off values were found to be 4.7 for the PV ratio (sensitivity 100%, specificity 90%, accuracy 93%), and 93 cm/s for the PV at the aortomesenteric portion (sensitivity 100%, specificity 85%, accuracy 89%). Conclusion: LRV sonography, including Doppler spectral analysis, can demonstrate LRV entrapment haemodynamically. 相似文献
95.
Hendra Budiawan Gi Jeong Cheon Hyung-Jun Im Soo Jin Lee Jin Chul Paeng Keon Wook Kang June-Key Chung Dong Soo Lee 《Nuclear Medicine and Molecular Imaging》2013,47(4):232-241
Purpose
Lymph node (LN) characterization is crucial in determining the stage and treatment decisions in patient with lung cancer. Although 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has a higher diagnostic accuracy in LN characterization than anatomical imaging, differentiating between metastatic and inflammatory LNs is still challenging because both could show high 18F-FDG uptake. The purpose of this study was to assess if the heterogeneity of the 18F-FDG uptake could help in differentiating between inflammatory and metastatic LNs in lung cancer, and to compare with other parameters.Methods
A total of 44 patients with adenocarcinoma of the lung, who underwent preoperative 18F-FDG PET/CT without having any previous treatments and were revealed to have 18F-FDG-avid LNs, were enrolled. There were 52 pathology-proven metastatic lymph nodes in 26 subjects. The pathology-proven metastatic LNs were compared with 42 pathology-proven inflammatory/benign LNs in 18 subjects. The coefficient of variation (CV) was used to assess the heterogeneity of 18F-FDG uptake by dividing the standard deviation of standardized uptake value (SUV) by mean SUV. The volume of interest was manually drawn based on the combined CT images of 18F-FDG PET/CT (no threshold is used). Comparisons were made with the maximum standardized uptake values (SUVmax), visual assessment of 18F-FDG uptake, longest diameter, and maximum Hounsfield units (HUmax).Results
Metastatic lymph nodes tended to have higher CVs than the inflammatory LNs. The mean CV of metastatic LNs (0.30 ± 0.08; range: 0.08–0.55) was higher than that of inflammatory LNs (0.17 + 0.06; range, 0.07–0.32; P < 0.0001). On receiver operating characteristic (ROC) curve analysis, the area under curve was 0.901, and using 0.20 as cut-off value, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 88.5 %, 76.2 %, 82.2 %, 84.3, and 83.0 % respectively. Accuracy of CV was slightly higher than SUVmax and diameter, but significantly higher than visual assessment and HUmax.Conclusions
In patients with adenocarcinoma of the lung having no prior treatments, metastatic LNs showed more heterogeneous 18F-FDG uptake than inflammatory LNs. Measuring the CV of the SUV derived from a manual volume of interest (VOI) can be helpful in determining metastatic LN of adenocarcinoma of the lung. Including diagnostic criteria of CV into the diagnostic approach can increase the accuracy of mediastinal node status. 相似文献96.
97.
98.
3-Arylisoquinolin-1(2H)-ones (2) are possible bioisosteres of the 5-[4'-(piperidinomethyl)phenyl]-2,3-dihydroimidazo[2,1-a]iso quinoline (1) which is in clinical evaluation for the treatment of cancer. Structure-activity relationship studies of 3-arylisoquinolin-1(2H)-ones (2) led to the synthesis of 3-arylquinolin-2(1H)-ones (3). A number of 3-phenyl substituted quinolin-2(1H)-ones were synthesized and tested for their in vitro antitumor activity against four different human tumor cell lines and 3-phenyl-N-benzyl-3,4-dihydroquinolin-2(1H)-one (12) showed the most potent activity. 相似文献
99.
Jung Hwa Kim Sun A Lee Tae-Beom Ahn Sung Sang Yoon Key Chung Park Dae-Il Chang Kyung Cheon Chung 《JOURNAL OF CLINICAL NEUROLOGY》2008,4(1):36-39
We describe a 64-year-old man with scrub typhus who presented with both polyneuropathy and cerebral infarction. A eurological examination revealed a confused mental state, stiff neck, hearing impairment, symmetric weakness, sensory loss, and ataxia. Electrophysiologic studies showed demyelinating sensorimotor polyneuropathy and sensorineural hearing loss. Brain magnetic resonance imaging showed multiple infarctions. Brain involvement or polyneuropathy associated with scrub typhus has been rarely reported, and the pathogenic mechanism underlying the multiple neurological complications remains to be elucidated. 相似文献
100.