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In this work, a systematic study has been conducted to optimize the process conditions and to evaluate kinetic parameters for hydrodesulfurization of coal tar. Experiments were performed in a trickle-bed hydrogenation unit at the temperatures, hydrogen pressures, and liquid hourly space velocities of 643–683 K, 9.6–13.6 MPa, and 0.3–0.5 h–1, respectively. Hydrogen to oil volume ratio was maintained constant at 1,200 LN/L in all cases. Optimization for hydrodesulfurization process conditions was investigated using the Box-Behnken experimental design by response surface methodology. A mathematical model that can be used for predicting sulfur content in products after hydrotreating was statistically developed and proven with analysis of variance. Kinetic studies for hydrodesulfurization reactions were studied using a power law model. The power law model showed that hydrodesulfurization of coal tar followed second-order kinetics and the activation energy was 42.15 kJ/mol, which is lower than other petroleum fractions. [ABSTRACT FROM PUBLISHER]

This paper discussed the reasons and the harms of high-speed railway's roadbed settlement in collapsible loess area. On the basis of the experimental simulation and mechanical analysis, the mechanism of fracture grouting is concluded, and a set of upper grouting test equipment is developed as well. Through a set of tests under different grouting pressures, and analyses on the soil's mechanical properties and displacement variations, a quadratic approximation formula is gained. Meanwhile, the mechanism for fracture grouting and the validity of laboratory simulation is tested and verified. In addition, the effect of fracture grouting on high-speed railway's roadbed consolidation in collapsible loess area is also got by fieldqs trial. The results of the current paper provide guide and reference for studying fracture grouting in collapsible loess area. [ABSTRACT FROM AUTHOR]

In this paper, a rigorous analysis for a microstrip cross is presented by using 2D generalized transmission-line equations. The 2D generalized transmission-line equation is developed from the 1D generalized transmission-line equation in [1], which was derived from circuit theory, while the equation coefficients are determined from full-wave numerical solutions. Although 1D generalized transmission-line equation can well model many microstrip structures, such as discontinuities and low-pass filters, it is confined to be used for those structures which can be regarded as 1D finite-length nonuniform transmission-line. For a microstrip cross, the novel 2D generalized transmission-line equation whose coefficients are determined by dynamic numerical methods can have broadband frequency characteristics. For the investigated microstrip cross, the S parameters for a frequency band from 4 GHz to 24 GHz can be calculated by using only one group of the 2D generalized equation at frequency of 14 GHz. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 378–380, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10613 [ABSTRACT FROM AUTHOR]

BaTi0.95Sn0.05O3 (BTS) ceramics were prepared by a solid reaction method using BaCO3, SnO2 and TiO2 as raw materials, and the influence of Yb2O3 addition on phase composition, microstructure and dielectric properties. The variation of dielectric properties at different sintering temperature was also discussed. The phase composition was analyzed by XRD pattern, and the microstructures of the samples were observed by SEM, and their dielectric properties were measured at 1 kHz. From the XRD patterns, the results show that all samples exhibited pure perovskite phase with no impurity phase, which suggested that the Yb3+ ion can be dissolved in BTS to form a homogenous solid solution. Doping Yb2O3 can also refine grain size. When BTS ceramics doped with Yb2O3 as 0.5 mol% and the sintering temperature is 1300 °C, the grain size is uniform and the growth is good. With the increase of Yb2O3 contents the dielectric constants increased and reached a maximum value at 0.5 mol%. The tangent loss decrease with the increase of Yb2O3 contents, and the peak temperature Tm at the maximum dielectric constant is shifted to lower temperature and broaden. When BTS ceramics doped with Yb2O3 as 0.5 mol% and the sintering temperature is 1300 °C the dielectric properties of the ceramic samples are optimized. [ABSTRACT FROM AUTHOR]

Hollow tin oxide (SnO2) nanobelts have been synthesized through a facile single capillary electrospinning method, and characterized by XRD, Raman, SEM, TEM and BET analysis. SnO2 hollow nanobelts exhibit excellent sensing performances to acetone at 260 °C. The response is up to 6.7 when the sensor is exposed to 5 ppm acetone. The response and recovery times are about 38 and 9 s, respectively. The sensor can detect acetone down to 5 ppm and up to 50,000 ppm. These results demonstrate that SnO2 hollow nanobelts can be used as the sensing material for fabricating high performance acetone sensors. The formation mechanism of the hollow nanobelts is also discussed, which is attributed to solvent evaporation rate, phase separation and collapse. [ABSTRACT FROM AUTHOR]

Objective: To analyze the occurrence of DKA in Chinese adults., Methods and Patients: We retrospectively reviewed the medical records of adults presenting with DKA in a tertiary referral center from January 1992 to December 1997. We classified these patients into 3 groups: type 1, type 2 and new-onset diabetes. Clinical features and follow-up treatment were analyzed., Results: One hundred and twenty patients with 141 episodes of DKA were included; 77 episodes (54.6%) were classified as being caused by type 2, 32 (22.7%) by type 1 and 32 (22.7%) by new-onset DM. The average age of type 2 patients was significantly higher. Of the 25 new-onset patients with follow-up for at least 12 months, 11 were not taking insulin. Of these 11 patients, 6 had a family history of DM and 5 had BMI greater than 26.4 kg/m2. The fasting plasma C-peptide values at various times of follow-up varied from 2.3 to 9.5 ng/ml in 6 of the 11 DKA-onset patients., Conclusion: In type 2 patients, the occurrence of DKA is usually associated with old age and another severe illness. "DKA-onset type 2 DM" reported in African-Americans and in Japanese is also observed in Chinese.

To establish possible cancerous aggressiveness between the metabolism of variously labeled [14C]glucose in the human breast invasive ductal carcinoma (IDC) tissues, we measured the rates of 14CO2 production from those tissues by using radiorespirometry, expressing the results as initial velocity (V) in nanomoles of 14CO2 min-1 g-1 of fresh tissues. The Vc data were compared with results of the SBR system, which grades up from I to III. Vc,1 values measured with [1-14C]glucose increased from 1.99-2.82 for SBR I to 3.90-4.09 for SBR II, finally reaching 4.83-7.04 for SBR III, thus matching clearly the increase of IDC cancerous aggressiveness. Conversely, data obtained from [3,4-14C]glucose and [6-14C]glucose decreased with increasing cancer stage: i.e., with [3,4-14C]glucose, Vc,3,4 values were 5.79-9.34 for SBR I, 4.45-4.84 for SBR II, and 2.35-1.90 for SBR III; with [6-14C]glucose, the corresponding Vc,6 values were 1.34-1.90, 1.33-1.41, and 0.72-0.79. The Vn,1/Vn,6 ratios were close to unity for normal tissues and for noncancerous tissues surrounding SBRI tumors. For cancerous tissues, however, the Vc,1/Vc,6 ratios were 1.5, 2.9, and 6.1-9.8 in IDC tissues graded as SBR I, II, and III, respectively. The results suggest the possible use of radiorespirometry as a tool to assess IDC aggressiveness.

Background: Uncertainty in diagnosing Huntington's disease (HD) may occur in the absence of a family history or typical movement disorders. HD is characterized by a progressive disturbance of typical movement disorders (i.e., chorea, athetosis), psychiatric symptoms (i.e., depression, insomnia, anxiety, suspiciousness), and cognitive deterioration, in the absence of a dominant family history of similar disorders. Often, some of these symptoms are missing, which makes the diagnosis difficult. In recent years molecular testing has become the gold standard for diagnosing HD. Diagnostic accuracy for HD on genetic screening of patients and their families is important. We evaluated a polymerase chain reaction (PCR) technique for the detection of CAG trinucleotide repeats in the Huntington IT15 gene on chromosome 4 for the diagnosis of HD., Methods: A segment of the Huntington gene was amplified by PCR using the primers HD-1 and HD-3 flanking the CAG repeat sequence. Genomic PCR was performed on DNA extracted from the peripheral leukocytes of 12 patients from three unrelated families. One family had no documented history of movement or mental disorders, while the other two did. These two, therefore, required pre-symptomatic testing and exclusion of diagnosis in a seemingly symptomatic case., Results: We successfully identified four subjects with expansion of CAG trinucleotide repeats in Huntington gene IT15 on chromosome 4. Movement disorder was present in three of these subjects. One was the sister of subject 4, who was asymptomatic. A sister of subject 9 was ruled out from having HD by PCR despite having depression symptoms, which are frequently seen in HD patients., Conclusions: Genetic testing is of prime importance in the establishment of an accurate diagnosis of Huntington's disease, especially in "sporadic" cases and presymptomatic family members, and for the exclusion of HD in family members with equivocal symptoms.

The relationships between carcinomatous aggressiveness and the glucolytic metabolism, namely the rate of 14CO2 production from [U-14C] glucose, are obtained from human breast tissues using radiorespirometry. The values are estimated as the initial velocity (V) expressed in eta 14CO2 x min-1 x g-1 of fresh tissues by [U-14C] glucose metabolism. The aggressiveness of the breast carcinomatous is diagnosed by the SBR grade system. As two control normal tissues, (V) are 0.86 to 0.90 from non-cancer patients. In carcinomatous tissues (Vc), there is an increase from 1.53 to 3.14, but in the corresponding surrounding non-cancer tissues (Vn) these show a decrease from 2.20 to 0.22 for SBR I, SNR II to SBR III. The ratio between (Vc) and (Vn) are found, according to carcinomatous aggressiveness, as 1.45 to 1.54, 1.69, 2.35 to 2.86 and 4.82 to 10.38 respectively for SBR I, lobular carcinoma, SBR II and SBR III; while the ratio is 1.04 for the normal tissue which come from non-cancer patients. The above results suggest the possibility of assessing the carcinomatous aggressiveness by radiorespirometry before a histopathological diagnosis, even in a lower aggressiveness as in SBR I cases which are difficult to diagnose and manage.

Debrisoquine 4-hydroxylase (CYP2D6) is one of the cytochrome P450 enzyme families that catalyze the breakdown of a variety of exogenous and endogenous compounds. Previous reports have suggested that genetic polymorphisms of debrisoquine 4-hydroxylase are associated with susceptibility to Parkinson's disease (PD) in Caucasians. To determine if CYP2D6 also confers susceptibility to PD in Chinese patients, we carried out a study of genetic association using three polymorphic markers of the CYP2D6 gene, 188C/T, 1934G/A (mutant B), and 4268G/C. No differences of allele or genotype frequencies of these three polymorphisms were detected upon comparison of primary PD patients (n=53) with normal controls (n=94). The 1934A allele (mutant B), which accounts for the majority of poor metabolizers in Caucasians, is extremely rare in Chinese. Our data do not support the suggestion that the CYP2D6 gene is related to PD susceptibility in Chinese.

This randomized double-blind controlled study was carried out to investigate the effect of 100 mg acetylsalicylic acid (ASA) per day on the secondary prevention of ischemic stroke. Patients who suffered a first ischemic stroke from 13 participating hospitals were enrolled. They were independent or only partially dependent in activities of daily living and all had received brain CT for diagnosis. Eligible patients were randomly allocated to the 100 mg ASA or the nicametate citrate (a vasodilator) groups, and trial medications were started within three to six weeks after the onset of stroke. The primary end point was cerebral reinfarction, and intracranial hemorrhage was classified as an adverse event. Four hundred and sixty-six patients participated in this study; and 222 cases (136 males and 86 females) were allocated to the ASA group while 244 cases (150 males and 94 females) were assigned to the nicametate group. No significant difference in baseline characteristics between the two groups was observed. Cerebral reinfarction developed 6.3% (14/222) in the ASA group and 11.9% (29/244) in the nicametate group. According to the Cox's proportional hazards model, the estimated risk ratio (ASA group vs. nicametate group) was 0.538, with a 95% confidence interval of 0.284-1.019. The result was of borderline statistical significance. The risk for cerebral reinfarction was reduced by almost 50% among those who took 100 mg ASA versus those who took nicametate.

A multichannel joint-transform correlator that incorporates a Dammann grating as a beam splitter is described. The Dammann grating splits a single incident beam into a two-dimensional array of equal-intensity beams, which form several channels for correlation. Each channel contains both a single target and a single reference. Optical experimental results are presented.

We evaluated 48 consecutive patients with periventricular lucencies (PVL) on CT scan of brain to determine the clinical significance of this finding. Twenty-one (43.7%) patients were demented; 27 (56.3%) patients had no dementia but had various other diseases. PVL were frequently associated with hypertension and previous stroke. We used a PVL scoring system to evaluate the degree of PVL. When the score was greater than 3.5, the sensitivity and specificity in separating vascular dementia from other diseases with PVL were 78% and 67% respectively (Kappa = 0.42). We conclude that although mild PVL may be a frequent but non-specific finding in patients with hypertension or previous stroke, moderate and severe PVL should raise the possibility of vascular dementia.

Levo-praziquantel is the left isomer of racemic praziquantel. Animal experiments showed that it is an active component of schistosomicidal activity, while dextro-praziquantel is almost ineffective. Clinical trials in three endemic areas of Schistosomiasis japonica indicated that the therapeutic efficacy of levo-praziquantel is superior to racemic praziquantel. Pharmacokinetic and pharmacodynamic activities of the stereoselectivity of praziquantel isomers (enantiomers) are discussed.

A standardized questionnaire was sent to family members or care-givers of 105 patients with dementia; 68 were returned. Eighty-eight percent of the patients were cared for at home by their spouses or adult children. The adverse impacts of dementia on patient family's economy, relations among family members, and social life are recognized. The majority of the subjects had only limited understanding of dementia. Having medical insurance helps the family in caring for the demented patients, emotionally and socially, but not financially. A better social welfare system, as well as health insurance, is recommended.

A 43-year-old woman suffered from low back pain and bilateral footdrop. A cisternal myelogram unexpected revealed multiple filing defects in the spinal canal extending from the lower cervical region to the caudal equina. Diagnostic exploration revealed numerous cystic organisms adhering to the spinal cord and nerve roots. Histopathological examination showed these organisms to be proliferative sparganum cestode larvae. Although these cestode larval infections have been reported a dozen times in humans from various parts of the world, this is probably the first reported case of spinal cord infection.