bluuebunny/crossref_metadata_2025_split huggingface dataset:
Robotic Surgery
Authors: Desai Jaydev P. , Yasha Kresh J. , Wechsler Andrew S. , Castellanos Andres E. , Meyers William C. 
Published: April 2006

Abstract
The development and growth of robotics in surgery has been significant within the last few years. Minimally invasive surgical procedures using long instruments deprive the surgeon of depth perception, dexterity, sense of touch, and the excellent hand‐eye coordination that they are so accustomed to in open procedures. What the surgeon loses presents excellent theoretical, experimental, and developmental opportunities for the engineer to develop “smarter” and more efficient systems for use in minimally invasive surgery, which consequently leads to better patient care and reduced morbidity. Recent advancements in the integration of robotic surgical systems in the operating room have led to improvements in minimally invasive surgery (MIS) by returning some of the lost faculties of surgeons, such as dexterity, improved 3‐D visualization of the surgical field, and better hand‐eye coordination. In addition, MIS procedures with robotic assistance can lead to a shorter hospital stay, reduced trauma, faster recovery times, and lower health‐care costs. This chapter will explore the innovations in robotics for surgery, such as deformation modeling for tool‐tissue interactions with soft tissues and organs, sensing and control, and model‐based teleoperation. Finally, the future direction of robotics in surgery will also be discussed.
Sepsis
Authors: Keith Scott L. , Conrad Steven A. 
Published: April 2006

Abstract

Sepsis is a state of systemic inflammation resulting from an unregulated and dysfunctional response of the innate immune system to an infectious stimulus. The sepsis response is initiated through cell surface signaling receptors that recognize specific microbial antigens, such as lipopolysaccharide, from gram‐negative bacteria. The signaling pathway activation results in increased activity of transcription factors in the cytoplasm, in particular nuclear factor
κ
B, followed by translocation to the nucleus and promotion of transcription of several early phase (proximal) inflammatory mediators, such as tumor necrosis factor‐
α
and interleukin‐1
β
. A number of later phase (distal) mediators are upregulated, producing activation of inflammation, anti‐inflammation, coagulation, and apoptotic pathways, with the endothelial cell playing a central role. This response is intended to function at a local level to contain the pathogenic process; however, systemic activation results in a systemic inflammatory response.

Therapies targeting single mediators of the sepsis response based on linear, reductionist approaches to sepsis pathophysiology have been largely ineffectual. The sepsis response is perhaps best approached as a nonlinear, redundant complex network. Mathematical models based on this approach are being developed and hold promise for better understanding of the sepsis response and for developing therapeutic targets. Recently described models include a mechanistic model based on ordinary differential equations describing the behavior of populations of cells and mediators, and an agent‐based model in which agents represent individual cells associated with the inflammatory response. Both of these models show promise in reproducing particular components of the sepsis response. Future successes in the treatment of sepsis will depend on improvements in modeling that will enable a better understanding of this complex process.
Stents
Authors: Lally C. , Kelly D.J. , Prendergast P.J. 
Published: April 2006

AbstractStents are devices implanted into vessels or ducts in the body to remove a constriction by holding the vessel or duct open. Deployment of stents is a major challenge; deployment is often performed by expanding a balloon onto which the stent has been crimped or by releasing a self‐expanding stent or a coiled stent from a restraining sheath. The expanding stent pushes the inner lumen radially outward to restore patency. Several biomechanical issues pertaining to stents exist, such as they should not overstress the vessel wall on expansion nor should they straighten a curved vessel, as that would generate high stresses at the ends of the stent. Restenosis (reformation of the original blockage) was always an issue with “bare metal stents” but this problem has, it seems, been largely overcome by coating the stents with an anti‐proliferative drug. A comprehensive description of the main cardiovascular stent designs is given and the main issues facing innovation in stent design in the future are outlined.
Tissue‐Engineered Cartilage
Authors: Pagnotto Michael R. , Chu Constance R. 
Published: April 2006

Abstract

The goal of cartilage tissue engineering is to recreate functional articular cartilage. The tissue must be able to fill chondral defects while maintaining the unique biomechanical characteristics that make articular cartilage functional. The goal may be accomplished either by inducing native repair cells to regenerate or through
ex vivo
techniques where cells are obtained from a patient and use to develop cartilage or pre‐cartilaginous constructs in the laboratory and then the constructs are surgically implanted back into the patient. As this chapter will demonstrate, extensive research continues to examine nearly every facet of cartilage tissue engineering.
Biochemical findings in common inborn errors of metabolism
Authors: Pasquali Marzia , Monsen Gavin , Richardson Leah , Alston Martha , Longo Nicola 
Published: April 2006

AbstractThe application of tandem mass spectrometry (MS/MS) to newborn screening has led to the detection of patients with a wider spectrum of inborn errors of metabolism. A definitive diagnosis can often be established early enough to start treatment before symptoms appear. Here, we review common biochemical findings in disorders caused by deficiency of 3‐methylcrotonyl‐CoA carboxylase, isobutyryl‐CoA dehydrogenase, 2‐methyl‐3‐hydroxybutyryl‐CoA dehydrogenase, 3‐ketothiolase, 2‐methylbutyryl‐CoA dehydrogenase, and medium chain acyl CoA dehydrogenase. The diagnosis of these disorders requires biochemical confirmation by measurement of plasma acylcarnitine profile, urine organic acids, and urine acylglycine profiles followed by measurement of enzyme activity or detection of causative mutations. Early treatment can improve the outcome of these disorders. © 2006 Wiley‐Liss, Inc.
Disorders of carnitine transport and the carnitine cycle
Authors: Longo Nicola , Amat di San Filippo Cristina , Pasquali Marzia 
Published: April 2006

AbstractCarnitine plays an essential role in the transfer of long‐chain fatty acids across the inner mitochondrial membrane. This transfer requires enzymes and transporters that accumulate carnitine within the cell (OCTN2 carnitine transporter), conjugate it with long chain fatty acids (carnitine palmitoyl transferase 1, CPT1), transfer the acylcarnitine across the inner plasma membrane (carnitine‐acylcarnitine translocase, CACT), and conjugate the fatty acid back to Coenzyme A for subsequent beta oxidation (carnitine palmitoyl transferase 2, CPT2). Deficiency of the OCTN2 carnitine transporter causes primary carnitine deficiency, characterized by increased losses of carnitine in the urine and decreased carnitine accumulation in tissues. Patients can present with hypoketotic hypoglycemia and hepatic encephalopathy, or with skeletal and cardiac myopathy. This disease responds to carnitine supplementation. Defects in the liver isoform of CPT1 present with recurrent attacks of fasting hypoketotic hypoglycemia. The heart and the muscle, which express a genetically distinct form of CPT1, are usually unaffected. These patients can have elevated levels of plasma carnitine. CACT deficiency presents in most cases in the neonatal period with hypoglycemia, hyperammonemia, and cardiomyopathy with arrhythmia leading to cardiac arrest. Plasma carnitine levels are extremely low. Deficiency of CPT2 present more frequently in adults with rhabdomyolysis triggered by prolonged exercise. More severe variants of CPT2 deficiency present in the neonatal period similarly to CACT deficiency associated or not with multiple congenital anomalies. Treatment for deficiency of CPT1, CPT2, and CACT consists in a low‐fat diet supplemented with medium chain triglycerides that can be metabolized by mitochondria independently from carnitine, carnitine supplements, and avoidance of fasting and sustained exercise. © 2006 Wiley‐Liss, Inc.
Glutaric acidemia type 1
Authors: Hedlund Gary L. , Longo Nicola , Pasquali Marzia 
Published: April 2006

AbstractGlutaric acidemias comprise different disorders resulting in an increased urinary excretion of glutaric acid. Glutaric acidemia type 1 (GA‐1) is an autosomal recessive disorder of lysine, hydroxylysine, and tryptophan metabolism caused by deficiency of glutaryl‐CoA dehydrogenase. It results in the accumulation of 3‐hydroxyglutaric and glutaric acid. Affected patients can present with brain atrophy and macrocephaly and with acute dystonia secondary to striatal degeneration in most cases triggered by an intercurrent childhood infection with fever between 6 and 18 months of age. This disorder can be identified by increased glutaryl (C5DC) carnitine on newborn screening. Urine organic acid analysis indicates the presence of excess 3‐OH‐glutaric acid, and urine acylcarnitine profile shows glutaryl carnitine as the major peak. Therapy consists in carnitine supplementation to remove glutaric acid, a diet restricted in amino acids capable of producing glutaric acid, and prompt treatment of intercurrent illnesses. Early diagnosis and therapy reduce the risk of acute dystonia in patients with GA‐1. © 2006 Wiley‐Liss, Inc.
Methylmalonic and propionic aciduria
Authors: Deodato Federica , Boenzi Sara , Santorelli Filippo M. , Dionisi‐Vici Carlo 
Published: April 2006

AbstractMethylmalonic and propionic aciduria (PA) are the most frequent forms of branched‐chain organic acidurias. These autosomal recessive disorders result from deficient activity of methylmalonyl‐CoA mutase and propionyl‐CoA carboxylase, respectively. Clinically, acute or chronic neurologic signs are caused by the accumulation of toxic compounds proximal to the metabolic block. Phenotype varies from severe neonatal‐onset forms with high mortality and poor outcome to milder forms with a later onset. In both cases the clinical course is dominated by the risk of relapses of life‐threatening episodes of metabolic decompensation and of severe organ failure. Despite improvement of treatment, the overall outcome remains disappointing with no major differences between the two diseases. The diagnosis is based on the presence of characteristic compounds in body fluids as detected by organic acid analysis in urine and acylcarnitine profile in blood. Therapy is based on low‐protein high‐energy diet, carnitine supplementation, and metronidazole. Some patients with methylmalonic aciduria (MMA) respond to pharmacological doses of vitamin B12. Given the poor long‐term prognosis, liver transplantation has been recently attempted as an alternative therapy to conventional medical treatment to cure the underlying metabolic defect. Nevertheless, the overall experience to date does not clearly demonstrate its effectiveness in preventing further deterioration or improving survival and quality of life. The recent implementation of neonatal screening by electrospray tandem mass spectrometry has decreased early mortality and improved the short‐term outcome, without changing the detection rate of both diseases in the screening population compared to clinically detected cases. However, the limited number of patients and the short duration of their follow‐up do not yet permit drawing final conclusions on its effect on the long‐term outcome of methylmalonic and propionic acidemia. © 2006 Wiley‐Liss, Inc.
Clinical, biochemical, and molecular spectrum of hyperargininemia due to arginase I deficiency
Authors: Scaglia Fernando , Lee Brendan 
Published: April 2006

AbstractThe urea cycle consists of six consecutive enzymatic reactions that convert waste nitrogen into urea. Urea cycle disorders are a group of inborn errors of hepatic metabolism that often result in life threatening hyperammonemia and hyperglutaminemia. Deficiencies of all of the enzymes of the cycle have been described and although each specific disorder results in the accumulation of different precursors, hyperammonemia and hyperglutaminemia are common biochemical hallmarks of these disorders. Arginase is the enzyme involved in the last step of the urea cycle. It catalyzes the conversion of arginine to urea and ornithine. The latter reenters the mitochondrion to continue the cycle. Hyperargininemia is an autosomal recessive disorder caused by a defect in the arginase I enzyme. Unlike other urea cycle disorders, this condition is not generally associated with a hyperammonemic encephalopathy in the neonatal period. It typically presents later in childhood between 2 and 4 years of age with predominantly neurological features. If untreated, it progresses with gradual developmental regression. A favorable outcome can be achieved if dietary treatment and alternative pathway therapy are instituted early in the disease course. With this approach, further neurological deterioration is prevented and partial recovery of skills ensues. Early diagnosis of this disorder through newborn screening programs may lead to a better outcome. This review article summarizes the clinical characterization of this disorder; as well as its biochemical, enzymatic, and molecular features. Treatment, prenatal diagnosis and diagnosis through newborn screening are also discussed. © 2006 Wiley‐Liss, Inc.
Toughening modification of PBT/PC blends with PTW and POE
Authors: Bai Huiyu , Zhang Yong , Zhang Yinxi , Zhang Xiangfu , Zhou Wen 
Published: April 2006

AbstractNew toughened poly(butylene terephthalate) (PBT)/bisphenol A polycarbonate (PC) blends were obtained by melt blending with ethylene–butylacrylate–glycidyl methacrylate copolymer (PTW) and ethylene‐1‐octylene copolymer (POE) in a twin‐screw extruder. The mechanical properties of PBT/PC blends were investigated. The presence of PTW or POE could improve the mechanical properties except for the tensile strength and flexural properties of the PBT/PC blends. However, a combination use of PTW and POE had a strong synergistic effect, leading to remarkable increases in the impact strength, elongation at break, and Vicat temperature and some reduction of the tensile strength and flexural properties. The relationship between mechanical properties and morphology of the PBT/PC/PTW/POE blends was studied. The morphology was observed by scanning electron microscopy and the average diameter of dispersed phase was determined by image analysis, and the critical interparticle distance for PBT/PC was determined. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 54–62, 2006
Synthesis, characterization, and thermodynamic properties of poly(3‐mesityl‐2‐hydroxypropyl methacrylate)
Authors: Açikses Aslişah , Kaya Ismet , Horoz Gökhan 
Published: April 2006

AbstractPoly(3‐mesityl‐2‐hydroxypropyl methacrylate) (PMHPMA) was synthesized in a 1,4‐dioxane solution with 2,2′‐azobisisobutyronitrile as the initiator at 60°C. The homopolymer and its monomer were characterized with 1H‐ and 13C‐NMR, Fourier transform infrared, differential scanning calorimetry, thermogravimetric analysis, size exclusion chromatography, and elemental analysis techniques. According to size exclusion chromatography analysis, the number‐average molecular weight, weight‐average molecular weight, and polydispersity index of PMHPMA were 65,864 g/mol, 215,375 g/mol, and 3.275, respectively. According to thermogravimetric analysis, the carbonaceous residue value of PMHPMA was 14% at 500°C. The values of the specific retention volume, adsorption enthalpy, sorption enthalpy, sorption free energy, sorption entropy, partial molar free energy, partial molar heat of mixing, weight fraction activity coefficient of solute probes at infinite dilution (Ω), and Flory–Huggins interaction parameter (χ) were calculated for the interactions of PMHPMA with selected alcohols and alkanes by the inverse gas chromatography method at various temperatures. According to Ω and χ, selected alcohols and alkanes were nonsolvents for PMHPMA at 423–453 K. Also, the solubility parameter of PMHPMA (δ2) was found to be 24.24 and 26.33 (J/cm3)0.5 from the slope and intercept of (δ/RT) − χ/V1 = (2δ2/RT)δ1 − δ/RT at 443 K, respectively [where δ1 is the solubility parameter of the probe, V1 is the molar volume of the solute, T is the column temperature (K), and R is the universal gas constant]. The glass‐transition temperature of PMHPMA was found to be 386 and 385 K by inverse gas chromatography and differential scanning calorimetry techniques, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 101–109, 2006
Bayesian solvency analysis with autocorrelated observations
Authors: Mendoza M. , E. Nieto‐Barajas L. 
Published: April 2006

AbstractMost financial institutions are required to comply with a minimum capital rule in order to face their obligations during a given period of time. Due to the random nature of the financial flows involved, the problem of assessing the amount of capital required must be analysed within a stochastic framework and the solution can be reduced to the estimation of a selected quantile. Given the financial impact of a specific capital requirement, a proper and careful choice of the underlying model is of great relevance. Here, we address the problem for insurance companies by proposing an autocorrelated model to describe the relative severity after a suitable transformation and compare the results with those of a model, which assumes independence among observations. We undertake a full Bayesian analysis and derive the reference priors for the models. Results are illustrated with a real data set from the Mexican insurance industry. Copyright © 2006 John Wiley & Sons, Ltd.
Revisiting distributed lag models through a Bayesian perspective
Authors: R. Ravines Romy , M. Schmidt Alexandra , S. Migon Helio 
Published: April 2006

AbstractThis paper aims to show to practitioners how flexible and straightforward the implementation of the Bayesian paradigm can be for distributed lag models within the Bayesian dynamic linear model framework.Distributed lag models are of importance when it is believed that a covariate at time t, say Xt, causes an impact on the mean value of the response variable, Yt. Moreover, it is believed that the effect of X on Y persists for a period and decays to zero as time passes by. There are in the literature many different models that deal with this kind of situation. This paper aims to review some of these proposals and show that under some fairly simple reparametrization they fall into a particular case of a class of Dynamic Linear Models (DLM), the transfer functions models. Inference is performed following the Bayesian paradigm. Samples from the joint posterior distribution of the unknown quantities of interest are easily obtained through the use of Markov chain Monte Carlo (MCMC) methods. The computation is simplified by the use of the software WinBugs.As an example, a consumption function is analysed using the Koyck transformation and the transfer function models. Then a comparison is made with classical cointegration techniques. Copyright © 2006 John Wiley & Sons, Ltd.
Duplication of 5q15‐q23.2: Case report and literature review
Authors: Douyard Jaclyn , Hawley Pamela , Shaham Meira , Kimonis Virginia 
Published: April 2006

AbstractBACKGROUNDPure partial trisomy of chromosome 5q is rare and cases have ranged over the entire region, making it difficult to describe a good phenotypic correlation to the cytogenetic duplication.CASEWe present a 4.5‐year‐old girl with a de novo direct duplication of chromosome 5q15‐q23.2. She has moderate developmental delay with lack of speech, microcephaly, and subtle dysmorphic features including prominent forehead, bulbous nose, epicanthic folds, protruding tongue, and slightly posteriorly‐rotated ears.CONCLUSIONSA comparison is made with other similar duplication cases reported in the literature and a general description of a proximal 5q duplication phenotype is given, with lack of speech as the principal feature. Birth Defects Research (Part A), 2006. © 2006 Wiley‐Liss, Inc.
Characterization of partially folded intermediates of papain in presence of cationic, anionic, and nonionic detergents at low pH
Authors: Naeem Aabgeena , Fatima Sadaf , Hasan Khan Rizwan 
Published: April 2006

AbstractA systematic investigation of the effects of detergents [Sodium dodecyl sulphate (SDS), hexa decyltrimethyl ammonium bromide (CTAB) and Tween‐20] on the structure of acid‐unfolded papain (EC.3.4.22.2) was made using circular dichroism (CD), intrinsic tryptophan fluorescence, and 1‐anilino 8‐sulfonic acid (ANS) binding. At pH 2, papain exhibits a substantial amount of secondary structure and is relatively less denatured compared with 6 M GdnHCl (guanidine hydrochloride) but loses the persistent tertiary contacts of the native state. Addition of detergents caused an induction of α‐helical structure as evident from the increase in the mean residue ellipticity value at 208 and 222 nm. Near‐UV CD spectra also showed the regain of native‐like spectral features in the presence of 8 mM SDS and 3.5 mM CTAB. Induction of structure in acid‐unfolded papain was greater in the presence SDS followed by CTAB and Tween‐20. Intrinsic tryptophan fluorescence studies indicate the change in the environment of tryptophan residues upon addition of detergents to acid‐unfolded papain. Addition of 8 mM SDS resulted in the loss of ANS binding sites exhibited by a decrease in ANS fluorescence intensity, suggesting the burial of hydrophobic patches. Maximum ANS binding was obtained in the presence of 0.1 mM Tween‐20 followed by CTAB, indicating a compact “molten‐globule”–like conformation with enhanced exposure of hydrophobic surface area. Acid‐unfolded papain in the presence of detergents showed the partial recovery of enzymatic activity. These results suggest that papain at low pH and in the presence of SDS exists in a partially folded state characterized by native‐like secondary structure and tertiary folds. While in the presence of Tween, acid‐unfolded papain exists as a compact intermediate with molten‐globule–like characteristics, viz. enhanced hydrophobic surface area and retention of secondary structure. While in the presence of CTAB it exists as a compact intermediate with regain of native‐like secondary and partial tertiary structure as well as high ANS binding with the partially recovered enzymatic activity, i.e., a molten globule state with tertiary folds. © 2006 Wiley Periodicals, Inc. Biopolymers 83: 1–10, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com