Kinetic urine creatinine determination with the Gemsaec analyzer

A rapid automated method for urinary creatinine with the Jaffé reaction is described. Interferences by protein, glucose and ketones are circumvented by the reaction rate kinetics. The precision and accuracy of this centrifugal method on the ENI-Gemsaec analyzer are comparable to the manual end-point Jaffé reaction with deproteinization and to the common Auto-Analyzer technique.     

炼钢厂电磁干扰与抑制措施

针对新余钢铁有限责任公司炼钢厂出现的电磁干扰现象,分析了产生电磁干扰的来源和途径,运用硬件隔离、接地、滤波等方法对原有自动控制系统进行了硬件和软件两方面的抗干扰改进,通过对原有系统采取综合防护措施,将工业环境里各类可能引起干扰的因素排除,保证了自动控制系统的正常工作,使系统误差控制在3‰以内.     

Early interference in a priming task with brief masked targets.

Priming effects were examined in 2 experiments with 216 undergraduates in which a pronunciation or lexical decision task was used. Attention was manipulated by varying the probability that prime and target would be strongly associated. Both experiments showed significant interference in the low attention condition and at the 200-msec SOA, presumably before the onset of consciously directed processing. Two subsequent experiments with 160 undergraduates used a short SOA and the low attention condition to determine the conditions under which this interference would occur by varying the interstimulus interval, target duration, and the mask. Interference occurred only when targets were brief and masked. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Formula creatinine clearance as a substitute for 24-hour creatine clearance in children with kidney transplantation

A 10-year-old German shepherd dog presented with a periodontal 10 mm interproximal defect between the left mandibular fourth premolar and first molar teeth. Bone graft removed from the caudoventral portion of the ipsilateral hemimandible was placed in the defect as a component of the periodontal treatment plan. The use of bone graft likely contributed to periodontal pocket reduction.     

Column-switching liquid chromatographic method for the simultaneous determination of iothalamic acid and creatinine in biological fluids

A column-switching liquid chromatographic method for simultaneous determination of iothalamate and creatinine in human serum and urine was developed. Iothalamate and creatinine were separated on a weakly acidic ion-exchange column (C1) by ion-exclusion chromatography and iothalamate excluded from the column was purified by gel chromatography on a hydrophilic gel column (C2) and then by ion-exchange chromatography on a weakly basic ion-exchange column (C3). Creatinine that was eluted from C1 after iothalamate was transferred to a hydrophilic gel column (C4) and then to a strongly acidic ion-exchange column (C5). The mobile phase for C1-C4 was a pH 3.8 propionate buffer (propionic acid-NaOH = 0.35 + 0.035 mol/kg in water) and a pH 5.6 propionate buffer (propionic acid-NaOH = 0.04 + 0.035 mol/kg in water) was used for C5. Diluted serum and urine samples could be injected directly on to C1, as the matrix of C1 is hydrophilic and C1 is backflushed after the transfer of the creatinine fraction from C1 to C4. Iothalamate and creatinine in the eluates were determined by measuring their ultraviolet absorption at 245 and 234 nm, respectively. The precision (R.S.D.) of the chromatographic method was 1.6% (n = 7) and 0.36% (n = 6) for diluted serum and urine with iothalamate concentrations of 1.0 and 10.0 mumol/l, respectively, and 0.85% (n = 7) and 0.55% (n = 7) for diluted serum and urine with creatinine concentrations of 5.77 and 272 mumol/l, respectively.     

Increased priming interference at a long SOA with brief masked targets.

Tests prediction of a model of priming proposed by B. E. McLeod and R. E. Walley (1989) in which interference (ITF) is caused by inhibitory processes between nodes in semantic memory. This model predicts that ITF normally found in a high cue validity condition at long stimulus onset asynchrony (SOA) will be considerably increased when a brief target is masked. 80 male and female, native English-speaking Ss participated; within S variables were prime type, prime relatedness, and target condition. 192 trials were given in 2 blocks of 96 trials; 25% were nonword trials. The task was a primed lexical decision with an SOA of 800 ms. Cue validity was high or low; targets were brief, masked in either block 1 or block 2 of trials. In the high cue validity condition, both reaction time (RT) and error data show increased ITF when the brief target was masked. Results confirm that target node activation is considerably reduced. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determination of serum creatinine by isotope dilution method using discharge-assisted thermospray liquid chromatography/mass spectrometry

A discharge-assisted thermospray (plasmaspray) liquid chromatography/mass spectrometric method for the determination of serum creatinine is described. The method incorporates stable isotope dilution using (D3)creatinine as an internal standard. Separation is performed in reversed-phase high-performance liquid chromatography using 0.01 M aqueous ammonium acetate as a flow solvent. Effluents are directly introduced to the mass spectrometer and [MH]+ ions are monitored during LC/MS using the selected ion monitoring method. Satisfactory agreement between the analytical result and the certified value of the serum sample of standard reference material and relative standard deviation ranging from 0.6% to 1.2% was obtained.     

Quantification of creatinine kinetic parameters in patients with acute renal failure

BACKGROUND: Urea kinetic modeling (UKM) and creatinine (Cr) kinetic modeling (CKM) are used in the nutritional evaluation of end-stage renal disease (ESRD) patients. Both the UKM-derived normalized protein catabolic rate (nPCR) and the CKM-derived estimate of lean body mass (LBM) may also provide important information in critically ill acute renal failure (ARF) patients. Estimation of LBM may be particularly useful as previous data demonstrate that malnutrition adversely influences outcome in ARF patients. METHODS: Eleven critically ill ARF patients (age 52 +/- 21 years; mean +/- SD) treated with continuous venovenous hemofiltration (CVVH) were the study group. They were analyzed at steady state with a single-pool variable-volume model that determined the creatinine generation rate (GCr) by a methodology that we have previously described. RESULTS: The CVVH ultrafiltrate production rate was 913 +/- 49 ml/hr, yielding a blood Cr clearance of 15.2 +/- 0.9 ml/min and a steady state serum Cr of 3.4 +/- 1.7 mg/dl. Daily creatinine generation normalized to body wt (creatinine index: CI) was 6.3 +/- 0.8 and 10.6 +/- 3.0 mg/kg/day for females (N = 4) and males (N = 7), respectively (P < 0.05). Estimated mean LBM was 30.0 +/- 2.0 and 41.2 +/- 7.0 kg in females and males, respectively (P < 0.05), while the same parameter normalized to body wt was 0.50 +/- 0.05 and 0.52 +/- 0.10, respectively. These values are substantially lower than those previously reported for both normal and ESRD patients. Regression analysis demonstrated both GCr (r2 = 0.96; P < 0.001) and LBM (r2 = 0.96; P < 0.001) were significantly correlated with steady state serum Cr in a linear manner. However, no significant correlation (r2 = 0.06; P = 0.24) between nPCR and CI was observed. CONCLUSIONS: These data suggest critically ill ARF patients have severe somatic protein depletion. This malnourished state is likely due to deficits established prior to the development of ARF, such as those secondary to underlying chronic illnesses or prolonged hospitalization, and deficits related to acute hypercatabolism. Quantitative assessment of malnutrition in ARF patients with this CKM-based methodology may permit a better understanding of predisposing factors and, consequently, facilitate the development of interventions designed to prevent malnutrition in these patients.     

抑制汽车点火系统电磁干扰的光电隔离方法

汽车发动机点火系统工作时产生的电磁辐射是车内最强的电磁干扰源,也是造成大多数电控单元(electrical control unit, ECU)误动作的主要原因.为了减小点火噪声对ECU的干扰,采用光电隔离技术来实现干扰源与控制电路的电气隔离.在分析点火系统电磁干扰形成机理的基础上,探讨了光电隔离技术抑制点火系统电磁干扰的可行性,设计了抑制点火系统电磁干扰的平台实验电路.实验结果表明,光电隔离电路在20~100 MHz频段抑制点火噪声效果明显,在解决汽车电磁兼容问题上是可行的.     

Effects of moderate-dose versus high-dose trimethoprim on serum creatinine and creatinine clearance and adverse reactions

The effects of a 10-day course of moderate-dose (10 mg/kg/day) or high-dose (20 mg/kg/day) trimethoprim therapy on serum creatinine, measured creatinine clearance, urinary creatinine excretion, and serum folate were studied in 20 healthy volunteers. Serum creatinine concentrations increased significantly during trimethoprim therapy, began to decrease near day 10, and returned to baseline during the washout phase at both dosage levels. At the same time, measured creatinine clearance and urine creatinine changed in the opposite direction. No clinical or statistical differences were noted between changes in the moderate- versus the high-dose phases. Serum folate concentration decreases during high-dose trimethoprim therapy were statistically significant. Adverse drug reactions in the two groups were statistically different during the first study period, with the high-dose group having a 75% incidence rate and the moderate-dose group having an 11% incidence rate (P < 0.02). Serum creatinine, measured creatinine clearance, and urinary creatinine excretion demonstrated statistically, but not clinically, significant changes during trimethoprim therapy. In addition, high-dose trimethoprim caused significantly more adverse drug reactions than moderate-dose trimethoprim in normal volunteers.