Introduction of a nonlinearity measure for principal component models

Although principal component analysis (PCA) is an important tool in standard multivariate data analysis, little interest has been devoted to assessing whether the underlying relationship within a given variable set can be described by a linear PCA model or whether nonlinear PCA must be utilized. This paper addresses this deficiency by introducing a nonlinearity measure for principal component models. The measure is based on the following two principles: (i) the range of recorded process operation is divided into smaller regions; and (ii) accuracy bounds are determined for the sum of the discarded eigenvalues. If this sum is within the accuracy bounds for each region, the process is assumed to be linear and vice versa. This procedure is automated through the use of cross-validation. Finally, the paper shows the utility of the new nonlinearity measure using two simulation studies and with data from an industrial melter process.     

RF SiP技术正转向无线设计主流

第1部分射频系统级封装(RF SiP,RF System-in-Pack-age)技术是一种对无线通信非常有用的封装平台,无线通信被如下事实所困,但由于目前SiP设计仍     

Long-term effect of lisinopril and atenolol on kidney function in hypertensive NIDDM subjects with diabetic nephropathy

The aim of our study was to evaluate whether inhibition of ACE (lisinopril 10-20 mg/day) can reduce the rate of decline in kidney function more than reducing blood pressure with conventional antihypertensive treatment (atenolol 50-100 mg/day), usually in combination with a diuretic. We performed a prospective, randomized, parallel study for 42 months, double blind for the first 12 months and single blind thereafter. Forty-three (21 lisinopril and 22 atenolol) hypertensive NIDDM patients with diabetic nephropathy were enrolled. Data from 36 patients (17 lisinopril and 19 atenolol, 60 +/- 7 years of age, 27 men) who completed at least 12 months of the study period are presented. At baseline, the two groups were comparable: glomerular filtration rate (51Cr-EDTA plasma clearance) was 75 +/- 6 and 74 +/- 8 ml x min(-1) x 1.73 m(-2), mean 24-h ambulatory blood pressure (A&D TM2420) was 110 +/- 3 and 114 +/- 2 mmHg, and 24-h urinary albumin excretion rate was 961 (range 331-5,727) and 1,578 (476-5,806) mg/24 h in the lisinopril and atenolol groups, respectively. The mean follow-up time was similar, 37 and 35 months in the lisinopril and atenolol groups, respectively. Mean ambulatory blood pressure was equally reduced in the two groups, 12 +/- 2 and 10 +/- 2 mmHg in the lisinopril and atenolol groups, respectively. Glomerular filtration rate declined in a biphasic manner with a faster initial (0 to 6 months) change of 1.25 +/- 0.49 and 0.81 +/- 0.29 ml x min(-1) x month(-1) followed by a slower sustained decline (6 to 42 months) of 0.59 +/- 0.10 and 0.54 +/- 0.13 ml x min(-1) x month(-1) in the lisinopril and atenolol groups, respectively. No significant differences were observed in either initial or sustained decline in glomerular filtration rate between the two groups. Urinary albumin excretion was reduced (% reduction of baseline) more in the lisinopril than in the atenolol group, at 55 (95% CI 29-72) and 15% (-13 to 34), respectively (P = 0.01). In conclusion, the relentless decline in kidney function characteristically found in hypertensive NIDDM patients with diabetic nephropathy can be reduced equally effectively by two antihypertensive treatments, the beta-blocker atenolol and the ACE inhibitor lisinopril.     

Ambulatory management of multiple gestation

Ambulatory management of multiple gestation requires careful and continuing care by the obstetrician. The initial evaluation should include a comprehensive history, including use of fertility enhancing drugs and ART, family history, social history; a general physical examination, including a pelvic examination; laboratory evaluation, including complete blood cell count, dipstick urinalysis for protein and glucose, urine culture, blood type, Rh factor and irregular blood antibody determination, serology for rubella, syphilis, hepatitis B surface antigen and varicella (if there is no history). A Papanicolaou smear should be done at the time of the pelvic examination, as should evaluation for bacterial vaginosis. Ultrasound assessment of placentation should be done at 14 weeks' gestation, but vaginal or perineal ultrasound of cervical length should be done at the initial visit. Other testing procedures should include repeat ultrasound evaluation for fetal growth every 4 weeks in a dichorionic placentation and every 3 weeks if monochorionic placentation is present. Triple screen MSAFP at 16-18 weeks' gestation and blood sugar screening at 22-26 weeks should be performed. After the first trimester, the patient should schedule physician visits every 2 weeks or less. Routine medications should include one prenatal vitamin per day, additional folic acid supplementation of 1.0 mg per fetus, supplemental iron preparation, and additional calcium to equal 1500 mg/day. The use of low-dose aspirin to prevent preeclampsia in twin gestations has not been adequately studied. Continuing vigilance by the knowledgeable obstetrician should occur. Multiple gestations should not be cared for by non-physician providers or by family physicians. Referral to a maternal-fetal medicine unit is recommended.     

Epoxy fatty acid ester plasticizers. Preparation and properties

Summary The preparation of epoxy fatty acid ester plasticizers has been reviewed. These plasticizers can be prepared by epoxidation reactions, utilizing a preformed peracid or anin-situ technique. A newin-situ epoxidation process, utilizing hydrogen peroxide and acetic acid in the presence of strong acid catalyst, has been described. Excellent conversions to epoxide have been achieved with a series of monounsaturated and polyunsaturated esters. Epoxy fatty acid esters are excellent plasticizers for vinyl resins. Their performance in a series of additional epoxy plasticizers of vegetable and marine origin is described. Novel epoxy plasticizers based upon mixed acetylated mono- and di-glyceride have been prepared and are found to have excellent plasticizer performance. Presented at the 28th fall meeting, American Oil Chemists’ Society, October 1954, Minneapolis, Minn.