bluuebunny/crossref_metadata_2025_split huggingface dataset:
Progressive Erosion of β-Cell Function Precedes the Onset of Hyperglycemia in the NOD Mouse Model of Type 1 Diabetes
Authors: Ize-Ludlow Diego , Lightfoot Yaima L. , Parker Matthew , Xue Song , Wasserfall Clive , Haller Michael J. , Schatz Desmond , Becker Dorothy J. , Atkinson Mark A. , Mathews Clayton E. 
Published: June 2011

OBJECTIVE
A progressive decline in insulin responses to glucose was noted in individuals before the onset of type 1 diabetes. We determined whether such abnormalities occurred in prediabetic NOD mice—the prototypic model for human type 1 diabetes.

RESEARCH DESIGN AND METHODS
Morning blood glucose was measured every other day in a cohort of NOD females. Glucose tolerance and insulin secretion were measured longitudinally by intraperitoneal glucose tolerance tests in NOD/ShiLtJ and BALB/cJ mice 6 to 14 weeks of age. Arginine-stimulated insulin secretion and insulin sensitivity were assessed during intraperitoneal arginine or intraperitoneal insulin tolerance tests.

RESULTS
During prediabetes, NOD females displayed a progressive increase in glucose levels followed by an acute onset of hyperglycemia. First-phase insulin responses (FPIRs) during the intraperitoneal glucose tolerance test (IPGTT) declined before loss of glucose tolerance in NOD. The failure of FPIR could be detected, with a decline in peak insulin secretion during IPGTT. Arginine-stimulated insulin secretion remained unchanged during the study period. The decline in insulin secretion in NOD mice could not be explained by changes in insulin sensitivity.

CONCLUSIONS
There was an impressive decline in FPIR before changes in glucose tolerance, suggesting that impairment of FPIR is an early in vivo marker of progressive β-cell failure in NOD mice and human type 1 diabetes. We portend that these phenotypes in NOD mice follow a similar pattern to those seen in humans with type 1 diabetes and validate, in a novel way, the importance of this animal model for studies of this disease.
Active Power Measurements - An Overview and a Comparison of DSP Algorithms by Noncoherent Sampling
Authors: Sedlacek Milos , Stoudek Zdenek 
Published: June 2011

Active Power Measurements - An Overview and a Comparison of DSP Algorithms by Noncoherent Sampling
This paper presents an overview of algorithms for one-phase active power estimation using digital signal processing in the time domain and in the frequency domain, and compares the properties of these algorithms for a sinusoidal test signal. The comparison involves not only algorithms that have already been published, but also a new algorithm. Additional information concerning some known algorithms is also included. We present the results of computer simulations in MATLAB and measurement results gained by means of computer plug-in boards, both multiplexed and using simultaneous signal sampling. The use of new cosine windows with a recently published iterative algorithm is also included, and the influence of additive noise in the test signal is evaluated.
DSPIC-Based Impedance Measuring Instrument
Authors: Santos José , Ramos Pedro 
Published: June 2011

DSPIC-Based Impedance Measuring Instrument
An implemented impedance measuring instrument is described in this paper. The device uses a dsPIC (Digital Signal Peripheral Interface Controller) as a processing unit, and a DDS (Direct Digital Synthesizer) to stimulate the measurement circuit composed by the reference impedance and the unknown impedance. The voltages across the impedances are amplified by programmable gain instrumentation amplifiers and then digitized by analog to digital converters. The impedance is measured by applying a seven-parameter sine-fitting algorithm to estimate the sine signal parameters. The dsPIC communicates through RS-232 or USB with a computer, where the measurement results can be analyzed. The device also has an LCD to display the measurement results.
DAC Testing Using Modulated Signals
Authors: Fexa Pavel , Vedral Josef , Svatoš Jakub 
Published: June 2011

DAC Testing Using Modulated Signals
This document analyses qualities of methods used for testing dynamical parameters of Digital-to-Analog Converters (DAC) using a multi-frequency signal. As the source for these signals, Amplitude Modulated (AM) and Frequency Modulated (FM) signals are used. These signals are often used in radio engineering. Results of the tests, like Effective Number of Bits (ENOB), Signal-to-Noise and Distortion (SINAD), are evaluated in the frequency domain and they are compared with standard results of Sine Wave FFT test methods. The aim of this research is firstly to test whether it is possible to test a DAC using modulated signals, secondly to reduce testing time, while estimating band performance of DAC.
Comparison of Amplitude-Based and Phase-Based Methods for Speed Tracking in Application to Wind Turbines
Authors: Urbanek Jacek , Barszcz Tomasz , Sawalhi Nader , Randall Robert 
Published: June 2011

Comparison of Amplitude-Based and Phase-Based Methods for Speed Tracking in Application to Wind TurbinesFocus of the vibration expert community shifts more and more towards diagnosing machines subjected to varying rotational speeds and loads. Such machines require order analysis for proper fault detection and identification. In many cases phase markers (tachometers, encoders, etc) are used to help performing the resampling of the vibration signals to remove the speed fluctuations and smearing from the spectrum (order tracking). However, not all machines have the facility to install speed tracking sensors, due to design or cost reasons, and the signal itself has to then be used to extract this information. This paper is focused on the problem of speed tracking in wind turbines, which represent typical situations for speed and load variation. The basic design of a wind turbine is presented. Two main types of speed control i.e. stall and pitch control are presented,. The authors have investigated two methods of speed tracking, using information from the signal (without relying on a speed signal). One method is based on extracting a reference signal to use as a tachometer, while the other is phase-based (phase demodulation). Both methods are presented and applied to the vibration data from real wind turbines. The results are compared with each other and with the actual speed data.
Inductive Sensor for Weighing of Mass
Authors: Lewandowski Janusz 
Published: June 2011

Inductive Sensor for Weighing of Mass
A new method measuring of mass in electronic system of scales has been described. The main element of this system is inductive measuring load cell, which was compared with strain gauge load cell. The aim of the paper is described advantages of the inductive measuring system of mass and explain some main problems of this system. Digital correction of the mechanical errors of the beam like: hysteresis, creep material of the beam under constant load, influence of ambient temperature was described.
Investigation of the Statistical Method of Time Delay Estimation Based on Conditional Averaging of Delayed Signal
Authors: Kowalczyk Adam , Hanus Robert , Szlachta Anna 
Published: June 2011

Investigation of the Statistical Method of Time Delay Estimation Based on Conditional Averaging of Delayed Signal
This paper presents the results of the theoretical and practical analysis of selected features of the function of conditional average value of the absolute value of delayed signal (CAAV). The results obtained with the CAAV method have been compared with the results obtained by method of cross correlation (CCF), which is often used at the measurements of random signal time delay. The paper is divided into five sections. The first is devoted to a short introduction to the subject of the paper. The model of measured stochastic signals is described in Section 2. The fundamentals of time delay estimation using CCF and CAAV are presented in Section 3. The standard deviations of both functions in their extreme points are evaluated and compared. The results of experimental investigations are discussed in Section 4. Computer simulations were used to evaluate the performance of the CAAV and CCF methods. The signal and the noise were Gaussian random variables, produced by a pseudorandom noise generator. The experimental standard deviations of both functions for the chosen signal to noise ratio (SNR) were obtained and compared. All simulation results were averaged for 1000 independent runs. It should be noted that the experimental results were close to the theoretical values. The conclusions and final remarks were included in Section 5. The authors conclude that the CAAV method described in this paper has less standard deviation in the extreme point than CCF and can be applied to time delay measurement of random signals.
Pathological effects and motor response threshold changes following radiofrequency application at various distances from the L-5 nerve root: an experimental study
Authors: Maarrawi Joseph , Kobaiter-Maarrawi Sandra , Ghanem Ismat , Ali Youssef , Aftimos Georges , Okais Nabil , Samaha Elie 
Published: June 2011

Object
Radiofrequency (RF) ablation is a minimally invasive technique often used percutaneously in the treatment of many conditions such as spasticity, pain, and osteoid osteoma. The purpose of this study was to assess the value of motor response threshold (MRT) as an indirect indicator of the RF generator's electrode to nerve distance, and to evaluate the effects of RF at various distances from a nervous structure.

Methods
The L-5 nerve root was studied in 102 Sprague-Dawley rats (sham contralateral side). Motor response thresholds at 0, 2, 4, 5, and 6 mm from the nerve root were assessed before and after RF application for 2 minutes at 80° C on Days 0 and 7. Radiofrequency was applied 0, 2, 4, 5, and 6 mm away from L-5 and with the addition of interposed cortical bone. The effects of RF application on MRT were studied, and subsequent nerve injury was evaluated using light microscopy pathological examination.

Results
There is a significant correlation between MRT and the distance between the electrode tip and L-5, with MRT less than 0.5 V when the electrode was in direct contact with the root. Electrical and pathological changes following RF application were more pronounced at 0 mm, with worsening seen on Day 7. Radiofrequency at 2 and 4 mm produced fewer electrical and histological deleterious effects on the nerve on Days 0 and 7, with an obvious improvement on Day 7. At 5 mm, electrical and histological abnormalities were minimal on Day 0 and were fully reversible on Day 7. At 6 mm and with interposed cortical bone, MRT and pathological findings were unchanged on Days 0 and 7.

Conclusions
The MRT proved to be a useful and reliable tool in decreasing nerve morbidity following RF ablation in animals and may be used in humans for the same purpose. It serves as an indirect indicator of the proximity of the RF generator's electrode tip to any adjacent motor nervous structure. A minimum safe distance of 5 mm between the electrode tip and the nerve is required to avoid irreversible nerve injury, unless a bony wall is interposed between them, thus serving as a nerve shield. In medical conditions that require RF ablation of the nerve, such as spasticity and pain, the MRT must be lower than 0.5 V. When a nerve lesion is to be avoided such as in cases of osteoid osteoma, an MRT higher than 2.5 V is considered safe, reflecting a distance greater than 5 mm.
Risk factors for posttraumatic vasospasm
Authors: Shahlaie Kiarash , Keachie Krista , Hutchins Irene M. , Rudisill Nancy , Madden Lori K. , Smith Karen A. , Ko Karen A. , Latchaw Richard E. , Muizelaar J. Paul 
Published: June 2011

Object
Posttraumatic vasospasm (PTV) is an underrecognized cause of ischemic damage after severe traumatic brain injury (TBI) that independently predicts poor outcome. There are, however, no guidelines for PTV screening and management, partly due to limited understanding of its pathogenesis and risk factors.

Methods
A database review of 46 consecutive cases of severe TBI in pediatric and adult patients was conducted to identify risk factors for the development of PTV. Univariate analysis was performed to identify potential risk factors for PTV, which were subsequently analyzed using a multivariate logistic regression model to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

Results
Fever on admission was an independent risk factor for development of PTV (OR 22.2, 95% CI 1.9–256.8), and patients with hypothermia on admission did not develop clinically significant vasospasm during their hospital stay. The presence of small parenchymal contusions was also an independent risk factor for PTV (OR 7.8, 95% CI 0.9–69.5), whereas the presence of subarachnoid hemorrhage or other patterns of intracranial injury were not. Other variables, such as age, sex, ethnicity, degree of TBI severity, or admission laboratory values, were not independent predictors for the development of clinically significant PTV.

Conclusions
Independent risk factors for PTV include parenchymal contusions and fever. These results suggest that diffuse mechanical injury and activation of inflammatory pathways may be underlying mechanisms for the development of PTV, and that a subset of patients with these risk factors may be an appropriate population for aggressive screening. Further studies are needed to determine if treatments targeting fever and inflammation may be effective in reducing the incidence of vasospasm following severe TBI.
Notch receptor and effector expression in von Hippel-Lindau disease–associated central nervous system hemangioblastomas
Authors: Merrill Marsha J. , Edwards Nancy A. , Lonser Russell R. 
Published: June 2011

Object
Central nervous system hemangioblastomas are the most common manifestation of von Hippel-Lindau (VHL) disease, an autosomal dominant tumor suppressor syndrome that results in loss of VHL protein function and continuous upregulation of hypoxia-inducible factors. These tumors are composed of neoplastic stromal cells and abundant vasculature. Stromal cells express markers consistent with multipotent embryonically arrested hemangioblasts, which are precursors for hematopoietic and vascular lineages. Notch receptors are transmembrane signaling molecules that regulate multiple developmental processes including hematopoiesis and vasculogenesis. To investigate the importance of notch signaling in the development of VHL disease–associated CNS hemangioblastomas, the authors examined the presence of the four notch receptors and downstream notch effectors in this setting.

Methods
The authors used surgical specimens obtained from confirmed VHL-associated hemangioblastomas. Immunohistochemical analysis for the four notch receptors and the downstream effectors was performed on formalin-fixed paraffin-embedded sections. Western blot analysis for HES1 was performed on frozen specimens.

Results
All four notch receptors are present in hemangioblastomas. NOTCH1 and NOTCH4 receptors were widely and prominently expressed in both the stromal and vascular cells, NOTCH2 receptor expression was limited to primarily stromal cells, and NOTCH3 receptor expression was limited to vascular cells. All 4 receptors displayed a nuclear presence. Immunohistochemical analysis also demonstrated that downstream notch effectors, HES1 and HES5, were uniformly expressed in tumor stromal and vascular cells, but HES3, HEY1, and HEY2 were not. Strong HES1 expression was confirmed by Western blot analysis.

Conclusions
The presence of all four notch receptors and downstream effector molecules suggests that the notch signaling pathway plays a critical role in the maintenance of the undifferentiated pluripotent phenotype of these tumors and in the associated vascular response. Moreover, the prominent expression of notch receptors in VHL-associated CNS hemangioblastomas reveals a new and possibly potent therapeutic target.
Effect of Timing and Duration of Tamsulosin Exposure on Complications in Resident-Performed Phacoemulsification
Authors: Ku Tina K. , Naseri Ayman , Han Ying , Porco Travis C. , Rutar Tina 
Published: June 2011

BACKGROUND AND OBJECTIVES:
Tamsulosin can cause intraoperative floppy iris syndrome and increase the risk of phacoemulsification complications. This study evaluated whether the risk of complications was associated with the timing or duration of preoperative tamsulosin exposure.

PATIENTS AND METHODS:
The current study was a retrospective review of electronic medical records of resident-performed phacoemulsification surgeries from 1998 to 2008 at a Veterans Administration Hospital. There were 73 eyes with recent tamsulosin exposure (within 30 days preoperatively) and 28 eyes with remote exposure (> 30 days preoperatively but within 3 years of surgery).

RESULTS:

There was a trend toward more total complications in recent compared with remote tamsulosin exposure cases (31.5% vs 14.3%,
P
= .09). A longer duration of tamsulosin use was not statistically associated with an increased risk of total complications.

CONCLUSION:
The authors were unable to detect a statistically significant effect of duration of tamsulosin use on the risk of intraoperative complications in phacoemulsification surgery.
Mental retardation, congenital heart malformation, and myelodysplasia in a patient with a complex chromosomal rearrangement involving the critical region 21q22
Authors: Melis Daniela , Genesio Rita , Cappuccio Gerarda , MariaGinocchio Virginia , Casa Roberto Della , Menna Giuseppe , Buffardi Salvatore , Poggi Vincenzo , Leszle Anna , Imperati Floriana , Carella Massimo , Izzo Antonella , Del Giudice Ennio , Nitsch Lucio , Andria Generoso 
Published: June 2011

AbstractThe region 21q22 is considered crucial for the pathogenesis of both Down syndrome (DS) and the partial monosomy 21q syndrome. Haploinsufficiency of the RUNX‐1 gene, mapping at 21q22 is responsible for a platelet disorder and causes predisposition to myelodysplastic syndrome (MDS). We describe a 3‐year‐old girl with mental retardation, congenital heart malformation, and subtle dysmorphic facial features. The patient developed thrombocytopenia when she was 2 years old. Bone marrow smear led to the diagnosis of myelodysplasia. Prenatal karyotyping had shown chromosome 21 pericentric inversion. Postnatally the array‐CGH revealed duplication at bands 21q11.2–21q21.1 and a simultaneous deletion involving the region 21q22.13–21q22.3. RUNX‐1 mRNA levels analyzed in patient's skin fibroblasts were reduced. In this child the monosomy of the region 21q22 likely had the main role in determining the phenotype. Although the RUNX‐1 gene is localized outside the deleted region, we speculate that RUNX‐1 reduced expression, is probably due to the deletion of regulatory factors and caused the hematologic disorder in the patient. The present report underlines also the importance of array‐CGH in characterizing patients with a complex phenotype. © 2011 Wiley‐Liss, Inc.
Neonatal progeroid syndrome (Wiedemann–Rautenstrauch syndrome): Report of three affected sibs
Authors: Arboleda Gonzalo , Morales Luis Carlos , Quintero Luis , Arboleda Humberto 
Published: June 2011

AbstractThe Wiedemann–Rautenstrauch syndrome (WRS) (OMIM 264090) is a rare progeroid entity. WRS patients are characterized by premature aging present at birth including pseudohydrocephalus, cranio‐facial disproportion, reduced subcutaneous fat, thin skin, rigid and thick joints, and neonatal teeth in some cases. Here we describe three sibs with WRS from unaffected parents and without consanguinity. Our findings support autosomal recessive inheritance in WRS and support the possibility of homozygocity mapping as a good approach to find the causative gene. © 2011 Wiley‐Liss, Inc.
Efficacy of modafinil on excessive daytime sleepiness in Prader–Willi syndrome
Authors: De Cock V. Cochen , Diene G. , Molinas C. , Masson V. Dauriac‐Le , Kieffer I. , Mimoun E. , Tiberge M. , Tauber M. 
Published: June 2011

AbstractExcessive daytime sleepiness is a frequent and a highly disruptive symptom to the daily routine of children with Prader–Willi Syndrome (PWS) and their families. The objective of the study was to evaluate the efficacy of modafinil, a central stimulant, on excessive daytime sleepiness in children and adolescents with PWS. The efficacy of modafinil was evaluated in this open label pilot study comparing the Epworth sleepiness scale before and after treatment. Ten patients with molecularly confirmed PWS and a complaint of excessive daytime sleepiness underwent a night‐time sleep recording and multiple sleep latency tests. One patient was excluded because of severe obstructive sleep apnea syndrome. Nine patients (4 males) with median age of 16 years (8–21) received modafinil at a starting dose of 100 mg/day. We found that all patients had excessive daytime sleepiness with an Epworth sleepiness scale at 14 (11–20) and mean sleep latency on multiple sleep latency tests at 5 (3–6) minutes. Moreover, six patients had at least two sleep‐onset rapid eye movement periods showing a narcolepsy‐like phenotype. Modafinil significantly improved sleepiness in all patients on the Epworth sleepiness scale from 14 (11–20) to 4 (3–12), (P = 0.007). Body mass index of the patients did not change significantly under treatment. No side effects were reported, and the drug was well‐tolerated. We posit that this open label case series shows good efficacy of modafinil in nine children and adolescents with PWS. © 2011 Wiley‐Liss, Inc.
Phenotypic variability of distal 22q11.2 copy number abnormalities
Authors: Tan Tiong Yang , Collins Amanda , James Paul A. , McGillivray George , Stark Zornitza , Gordon Christopher T. , Leventer Richard J. , Pope Kate , Forbes Robin , Crolla John A. , Ganesamoorthy Devika , Burgess Trent , Bruno Damien L. , Slater Howard R. , Farlie Peter G. , Amor David J. 
Published: June 2011

AbstractThe availability of microarray technology has led to the recent recognition of copy number abnormalities of distal chromosome 22q11.2 that are distinct from the better‐characterized deletions and duplications of the proximal region. This report describes five unrelated individuals with copy number abnormalities affecting distal chromosome 22q11.2. We report on novel phenotypic features including diaphragmatic hernia and uterine didelphys associated with the distal microdeletion syndrome; and frontomedial polymicrogyria and callosal agenesis associated with the distal microduplication syndrome. We describe the third distal chromosome 22q11.2 microdeletion patient with Goldenhar syndrome. Patients with distal chromosome 22q11.2 copy number abnormalities exhibit inter‐ and intra‐familial phenotypic variability, and challenge our ability to draw meaningful genotype–phenotype correlations. © 2011 Wiley‐Liss, Inc.
Adults with Rubinstein–Taybi syndrome
Authors: Stevens Cathy A. , Pouncey Jill , Knowles Darcy 
Published: June 2011

AbstractInformation in the medical literature regarding adults with genetic syndromes is limited, making the care of these patients challenging. We conducted a questionnaire study of adults with Rubinstein–Taybi syndrome that addressed medical problems, education, independence, and behavior. The most common medical problems included short stature, obesity, visual difficulties, keloids, eating problems, spine curvature, and joint problems. The adults had typically moderate mental retardation, but most achieved some independence in self‐care and communication; many participated in supported work situations. However, approximately one‐third were said to have some decreased abilities over time. Behavior problems were common and often worsened with age. Very few of the study participants were seeing a geneticist as an adult. Long‐term involvement of geneticists and education of adult primary care providers may help with many of the challenges facing adults with RTS and their families. © 2011 Wiley‐Liss, Inc.