An ISB-consistent Denavit-Hartenberg model of the human upper limb for joint kinematics optimization: validation on synthetic and robot data during a typical rehabilitation gesture.

Several biomedical contexts such as diagnosis, rehabilitation, and ergonomics require an accurate estimate of human upper limbs kinematics. Wearable inertial measurement units (IMU s) represent a suitable solution because of their unobtrusiveness, portability, and low-cost. However, the time-integration of the gyroscope angular velocity leads to an unbounded orientation drift affecting both angular and linear displacements over long observation interval. In this work, a Denavit-Hartenberg model of the upper limb was defined in accordance with the guidelines of the International Society of Biomechanics and exploited to design an optimization kinematics process. This procedure estimated the joint angles by minimizing the difference between the modelled and IMU-driven orientation of upper arm and forearm. In addition, reasonable constraints were added to limit the drift influence on the final joint kinematics accuracy. The validity of the procedure was tested on synthetic and experimental data acquired with a robotic arm over 20 minutes. Average rms errors amounted to 2.8 deg and 1.1 for synthetic and robot data, respectively. Clinical Relevance - The proposed method has the potential to improve robustness and accuracy of multi-joint kinematics estimation in the general contexts of home-based tele-rehabilitation interventions. In this respect adoption of multi-segmental kinematic model along with physiological joint constraints could contribute to address current limitations associated to unsupervised analysis in terms of monitoring and outcome assessment.

The posterior bundle of the elbow medial collateral ligament: biomechanical study and proposal for a new reconstruction surgical technique.

BACKGROUND: The medial collateral ligament (MCL) is one of the primary elbows stabilizers. It is composed of an anterior bundle (AB), a posterior bundle (PB) and a transverse bundle. In elbow dislocations, until today MCL reconstruction has addressed the AB only. The purpose of this paper is to understand the biomechanical role of the PB of the MCL and to propose a new surgical technique for the simultaneous reconstruction of the anterior and posterior bundles, preventing the risk of recurrent posterior dislocation or posteromedial rotational instability (PMRI). MATERIALS AND METHODS: Sixteen cadaveric elbows were subjected to a force in compression, supination valgus and pronation varus. The residual stability was evaluated in three conditions: intact MCL, sectioned AB and sectioned AB + PB. The tests were performed in collaboration with the Department of Mechanical and Aerospace Engineering of the Politecnico di Torino. In six elbows, the MCL was then reconstructed with the new technique. RESULTS: Complete posterior elbow dislocation does not occur until the PB is sectioned. The section of the AB alone causes elbow instability in valgus stress, but not a dislocation. The reconstruction of the AB and the PB using the described technique allows a good recovery of range of motion and joint stability. CONCLUSIONS: The PB of the MCL has a primary role in elbow stability against valgus stress, and it prevents elbow posterior dislocation at all flexion angles. The described reconstruction technique should reduce the risk of residual PMRI.

Effects of botulinum neurotoxin on spatio-temporal gait parameters of patients with chronic stroke: a prospective open-label study.

BACKGROUND: Nowadays, administration of botulinum neurotoxin type A is considered a safe, well tolerated and effective treatment for muscles tone reduction in focal spasticity care. Lack of evidence regards instead its functional role on gait parameters, as well patterns. AIM: To assess the botulinum neurotoxin treatment efficacy on chronic poststroke subjects, in order to investigate its functional effects on spatio-temporal gait parameters, in addition to the evaluation of spasticity grade based on clinical scales. DESIGN: A prospective open-label study along 16-weeks trials. SETTING: Outpatient neurophysiology rehabilitation structure and laboratory of movement and gait analysis. POPULATION: Twenty chronic poststroke patients, suffering from equinovarus foot deformity, with a stabilized hemiparesis were recruited according to inclusion criteria of the protocol. METHODS: Single neurotoxin-based local intramuscular injections were given according to a specific protocol concerning both the considered muscles and the relative toxin doses, with a maximum total dose ranged between 200 U and 400 U. Patients were observed both at baseline (t0) and for 4 following monthly visits (t1, t2, t3, t4) after injections at baseline. Gait analysis sessions were performed at each visit, by means of a video-cameras based system and body reflective markers attached to the body, based on a protocol. Authors focus on both global and local gait temporospatial parameters, such as walking speed, stride-length, cadence, stride-time, step-width, single limb support, double support and limp index to point out the functional changes due to the treatment. For comparison prior to and after the treatment, clinical scales like Modified Ashworth Scale, Berg Balance Scale and Rivermead Mobility Index have been also considered. RESULTS: Subsequent to the neurotoxin intramuscular injections, patients reported statistical significant gait improvements after 90 days (t3) regarding temporospatial parameters: (P<0.05) for walking speed, single limb support and double support and (P<0.10) for stride-length, stride-time, cadence and step-width. CONCLUSION: The botulinum neurotoxin treatment has demonstrated its efficacy for a functional recovery of gait, as pointed out by a statistically significant improvement of some spatio-temporal parameters. Thus, the analyzed changes reveal an improved balance and self-confidence in gait. Studies involving a wider population data are nevertheless needed to better confirm this efficacy. CLINICAL REHABILITATION IMPACT: The poststroke botulinum neurotoxin-based treatment is a safe and potentially useful neurorehabilitative approach for the analyzed data.

Time- and temperature-dependent migration studies of Irganox 1076 from plastics into foods and food simulants.

The study provides an exhaustive set of migration data for octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 1076) from low-density polyethylene (LDPE) in several food matrices. Irganox 1076 was used as a model migrant because it represents one of the typical substances used as an antioxidant in food packaging polymers. Kinetic (time-dependent) migration studies of Irganox 1076 were performed for selected foodstuffs chosen with different physical-chemical properties and in relation to the actual European food consumption market. The effect of fat content and of the temperature of storage on the migration from plastic packaging was evaluated. The results show that migration increased with fat content and storage temperature. All data obtained from real foods were also compared with data obtained from simulants tested in the same conditions. In all studied cases, the kinetics in simulants were higher than those in foodstuffs. The work provides data valuable for the extension of the validation of migration model developed on simulants to foodstuffs themselves.

Rapid multi-analyte quantification of benzophenone, 4-methylbenzophenone and related derivatives from paperboard food packaging.

Photo-initiators are used in printing inks hardened with UV light and one of the most commonly used photo-initiators is benzophenone (BP). Recent notifications under the Rapid Alert System for Food and Feed have shown migration of 4-methylbenzophenone (4-MBP) from packaging into cereals. A specific migration limit exists for BP of 0.6 mg kg(-1) for its use as an additive in plastics. There is no specific European legislation covering cardboard boxes and/or printing inks for food contact use. However, due to the high levels detected, the European Food Safety Authority (EFSA) published recommendations and the Standing Committee for the Food Chain and Animal Health endorsed a limit of 0.6 mg kg(-1) for the sum of BP and 4-MBP. While studies have been published on photo-initiators in the past, there is a fundamental lack of data on 4-MBP especially for its combined analysis with others. We present an HPLC method with diode array detector to simultaneously determine the levels of BP, 4-MBP as well as 7 other possible derivatives from secondary packaging for food applications. The method was tested and applied to 46 samples of paperboard for secondary packaging collected both from supermarkets and directly from a paperboard supplier. In addition, a survey was conducted on recycled paperboard (n = 19) collected from a supplier, to evaluate the background quantity of BP and other derivatives in recycled board. The most abundant photo-initiator found in the survey was BP, in 61% of samples, and 4-MBP was found in 30% of the samples. It seems that these compounds are used to replace one another. Other derivatives were found in minor quantities. Traces of BP were also found in 42% of the samples of recycled, unprinted board.

Development of a multimethod for the determination of photoinitiators in beverage packaging.

Photoinitiators are ink components used in the printing of food packaging. The aim of the present study was to develop a multimethod for the analysis of photoinitiators in paperboard packages and commercial beverage packages. The proposed method is simple and fairly rapid. Extraction is carried out with acetonitrile. A reverse-phase high performance liquid chromatography (HPLC) method with UV detection was developed to quantify the 6 selected photoionitiators. Total HPLC time analysis was 30 min and the flow-rate was 1 mL/min. Method validation parameters such as linearity and detection limit are reported. Recovery of all photoinitiators (at 1 mg/kg) from orange juice was satisfactory (mean = 88.4%; ranging from 84.6% to 93.4%). Recovery of benzophenone and Irgacure 651 was good (ranging from 85.2% to 98.1% and 86.1% to 92.2%, respectively) at the 4 concentrations studied (0.1, 0.2, 0.5, and 1 mg/kg). Commercial beverage packages were analyzed and when photoinitiators were detected, the beverages were also analyzed.

Development of an analytical method for the determination of photoinitiators used for food packaging materials with potential to migrate into milk.

Photoinitiators are used in the curing process during UV printing of food carton labels. The alarm concerning the detection of a photoinitiator, 2-isopropyl thioxanthone (ITX), in food samples packed with cartons printed with UV-cured inks has focused the attention of legislative authorities on the potential migrants from packaging inks into foods. For this reason it is very important to carry out analytical methods for the detection of those compounds in food as potential migrants from packaging. The aim of the present work was to develop a multimethod for the analysis of 6 photoinitiators in milk. The selected photoinitiators were Irgacure 184, benzophenone, Irgacure 651, Irgacure 907, Quantacure ITX, and Quantacure EHA (2-ethylhexyl-4-dimethylaminobenzoate). Milk (10 mL) extraction was carried out by using ammoniac and hexane. The supernatant was evaporated and the residue was redissolved with acetonitrile. Then, the extract was analyzed by HPLC-UV. Calibration lines were carried out over the concentration range of 0.1 to 10 mg/L. The calibration data presented high correlation coefficients (>0.9999). Mean recoveries (n = 6) of the 6 photoinitiators were 83.4% (residual standard deviation = 2.3%) at 0.5 mg/kg and 81.0% (residual standard deviation = 4.6%) at 1 mg/kg. Several milk samples and their respective packaging cartons were analyzed. Results were confirmed by HPLC-mass spectrometry.

Solid-phase micro-extraction (SPME-GC) and sensors as rapid methods for monitoring lipid oxidation in nuts.

Dry foods with high fat content are susceptible to lipid oxidation, which involves a quality deterioration of the product, since this process is responsible for the generation of off-flavours. Hexanal is considered to be a good shelf-life indicator of such oxidation products. In addition, due to its high volatility, hexanal can be easily determined by fast headspace analytical techniques. For this reason an electronic nose comprising ten metal oxide semiconductors (MOS) and a solid-phase microextraction (SPME) coupled with gas chromatography and flame ionization detector (GC-FID) method were compared in order to determine hexanal formed in hazelnuts during storage under different conditions (room temperature, 40 degrees C, ultraviolet light, with and without oxygen scavenger). The results obtained by the two methods showed a good correlation, confirming the possibility of using a multi-sensor system as a screening tool for the monitoring of shelf-life and oxidation state of nuts.

Survey of 2-ethylhexanoic acid in baby food.

A solid-phase microextraction method was developed and used to perform a survey of 2-ethylhexanoic acid (2-EHA) in 63 samples of baby food from 13 European Union countries, as well as from Norway and Switzerland. The levels of 2-EHA did not exceed 3.4 mg kg(-1). The concentrations of 2-EHA in 53 samples (84%) were in the range between <0.1 and 0.5 mg kg(-1). Ten samples showed the presence of the compound in the range between 0.5 and 3.4 mg kg(-1). An exposure assessment showed that the intake of 2-EHA does not exceed the tolerable daily intake (TDI) for infants of 6-12 months of age except one occurrence when taking the worst-case food consumption data available and the highest level of contamination of the survey. In the other cases, the levels of 2-EHA are at 13-fold below the TDI.

Solid-phase microextraction method for the determination of hexanal in hazelnuts as an indicator of the interaction of active packaging materials with food aroma compounds.

Fatty foods are susceptible to lipid oxidation resulting in deterioration of product quality due to the generation of off-flavours. Hexanal is a good indicator of rancidity. Therefore, a method based on solid-phase microextraction (SPME) coupled to gas chromatograph with flame ionization detection was developed to determine hexanal formation in hazelnuts during storage. Optimum conditions were as follows: carboxen-polydimethylsiloxane 75 microm fibre, extraction time 10 min, equilibrium time 10 min and equilibrium temperature 60 degrees C. The effect of oxygen scavengers on the oxidation process was also evaluated by measuring hexanal formation in hazelnuts stored with/without oxygen absorber sachets. Oxygen scavengers were shown to reduce oxidation; however, analysis of the sachet revealed that other volatile compounds from the headspace were also absorbed.

Functional barriers: properties and evaluation.

Functional barriers are multilayer structures deemed to prevent migration of some chemicals released by food-contact materials into food. In the area of plastics packaging, different migration behaviours of mono- and multilayer structures are assessed in terms of lag time and of their influence of the solubility of the migrants in food simulants. Whereas barriers to oxygen or to aromas must prevent the diffusion of these compounds under conditions of use, a functional barrier must also be efficient under processing conditions, to prevent diffusion of substances when the polymer layers are in contact at high (processing) temperatures. Diffusion in melted polymers at high temperatures is much slower for glassy polymers, than in polymers that are rubbery at ambient temperature. To evaluate the behaviour of functional barriers under conditions of use, a set of reference diffusion coefficients in the 40-60 degrees C range were determined for 14 polymers. Conditions for accelerated migration tests are proposed based on worst-case activation energy in the 40-60 degrees C range. For simulation of migration, numerical models are available. The rules derived from the models can be used both by industry (to optimize a material in terms of migration) or by risk assessors. Differences in migration behaviour between mono- and multilayer materials are discussed.

Evaluating the migration of ingredients from active packaging and development of dedicated methods: a study of two iron-based oxygen absorbers.

The behaviour of two commercial oxygen-scavenging products with respect to migration of active ingredients into foodstuffs was investigated. Migrants were identified, and by using appropriate analytical methods, migration was determined in a variety of liquid, solid or gelled food simulants and foods. Simulants were chosen to cover a range of water activities and viscosities. Foods and the gelled food simulant agar were packed with and without vacuum, and with the oxygen scavenger in various locations relative to the packed food. The main migrants, as identified by X-ray fluorescence spectrometry, infrared spectroscopy and scanning electron microscopy with energy-dispersive spectrometry were Na(+) and Cl(-) in non-acidic aqueous simulants, and Na(+), Cl(-) and Fe(2+) in 3% acetic acid. Migration into aqueous simulants exceeded the current European Union limit for total migration from plastic materials (assumed to be currently applicable to these systems) and was probably excessive by any reasonable standard. However, neither oxygen scavenger appeared to release significant quantities of migrants into solid foods when the scavenger was properly located in the package and the packing process does not favour the contents becoming wet by water released from the food.

[Model of integrated hospital project for the management of patients at risk of sudden death syndrome]. / Modello di progetto integrato Ospedale-Territorio per la gestione dei pazienti a rischio di SIDS.

Home cardiorespiratory monitoring (HM) is an accepted practice in infants at high risk for Sudden Infant Death Syndrome (SIDS) as those with the following conditions: 1) Siblings of SIDS; 2) Apparent Life Threatening Events (ALTE); 3) Apneas of prematurity. From 1998 the Division of Neanotology of the Policlinico of Modena has followed prospectively infants at high risk for SIDS, in collaboration with the General Health Service. To support the clinical trial 10 apnea monitors were provided by the General Health Service and managed from the Department of Neonatology. During 18 months 24 infants have been followed by HM, and among then 20 were at risk of SIDS (11 female and 9 male): 7 were siblings of SIDS (35%); 10 had previous episodes of ALTE (50%); 3 were born prematurely and had persistent apneas before discharge (15%). The mean period of HM was 5.85 months. None of the infants died for SIDS or had episodes of ALTE that required resuscitation measures. In only one case parents stopped earlier than recommended, but personal interview to parents showed that all the others families gained benefits and reassurance from HM.

[Sepsis caused by Corynebacterium xerosis in neonatology: report of a clinical case]. / Sepsi da Corynebacterium xerosis in neonatologia: descrizione di un caso clinico.

The pathogenicity of the nondiphtheria corynebacteria, most commonly known as coryneform bacteria in humans has been recognized in the last two decades. Corynebacterium xerosis is part of the normal flora of the skin, nasopharynx, conjunctives and it has recently been isolated from vaginal swabs. During the last few years, there has been an increased number of case reports claiming an association of C. xerosis with diseases, like septicemia, endocarditis, pleuropneumonia, peritonitis, osteomyelitis, septic arthritis, mediastinitis, meningitis, ventriculitis specially in immunocompromised patients or surgical patients. Infections due to C. xerosis have been reported rarely in newborn. We report a case of sepsis due to C. xerosis in a newborn without evident immunodeficiency. Our case further support the recognition of C. xerosis as a human pathogen and reinforces the fact that it should not be routinely considered as a contaminant.

Primary hypergammaglobulinemic purpura associated with IgG2 deficiency. A case report.

Hypergammaglobulinemic purpura is a rare disease in children. We report a case of a 12 year-old girl with a history of frequent infections. We found the presence of IgG2 deficiency despite polyclonal hypergammaglobulinemia. An IgG subclass determination should be obtained in every child with polyclonal hypergammaglobulinemia and features of immunodeficiency.