2,452 research outputs found
Utility of virosomal adjuvated influenza vaccines: a review of the literature
In spite of the efforts of the World Health Organization (WHO), influenza continues to be a major public health problem, both because of its impact on the health of subjects at risk, such as the elderly, and because of the economic burden that it places on society. Adjuvants are agents which, when incorporated into vaccines, enhance the immunogenicity of their antigens. The need for ever more immunogenic and efficacious influenza vaccines has led to the development of innovative vaccines. One of these, the viro- somal vaccine, has been on the market since 1997. The results obtained through controlled clinical studies and wide- spread application in the field suggest that the virosomal vaccine is not only an important tool for the prevention of seasonal influ- enza but also a valid means of potentiating the effect of a pan- demic influenza vaccine and, perhaps, of preparing multivalent or combined vaccines
Developing models of aerosol representation to investigate composition, evolution, optical properties, and CCN spectra using measurements of size-resolved hygroscopicity
A Differential Mobility Analyzer/Tandem Differential Mobility Analyzer (DMA/TDMA) was used to measure size distributions, hygroscopicity, and volatility during the May 2003 Aerosol Intensive Operational Period at the Central Facility of the Atmospheric Radiation Measurement Southern Great Plains site. Hygroscopic growth factor distributions for particles at eight dry diameters ranging from 0.012 µm to 0.600 µm were measured. These measurements, along with backtrajectory clustering, were used to infer aerosol composition and evolution. The hygroscopic growth of the smallest and largest particles analyzed was typically less than that of particles with dry diameters of about 0.100 µm. Condensation of secondary organic aerosol on nucleation mode particles may be responsible for the minimal growth observed at the smallest sizes. Growth factor distributions of the largest particles typically contained a non-hygroscopic mode believed to be composed of dust. A model was developed to characterize the hygroscopic properties of particles within a size distribution mode through analysis of the fixed-size hygroscopic growth measurements. This model was used to examine three cases in which the sampled aerosol evolved over a period of hours or days. Additionally, size and hygroscopicity information were combined to model the aerosol as a population of multi-component particles. With this model, the aerosol hygroscopic growth factor f(RH), relating the submicron scattering at high RH to that at low RH, is predicted. The f(RH) values predicted when the hygroscopic fraction of the aerosol is assumed to be metastable agree better with measurements than do those predicted under the assumption of crystalline aerosol. Agreement decreases at RH greater than 65%. This multi-component aerosol model is used to derive cloud condensation nuclei (CCN) spectra for comparison with spectra measured directly with two Desert Research Institute (DRI) CCN spectrometers. Among the 1490 pairs of DMA/TDMA-predicted and DRI-measured CCN concentrations at various critical supersaturations from 0.02-1.05%, the sample number-weighted mean R2 value is 0.74. CCN concentrations are slightly overpredicted at both the lowest (0.02-0.04%) and highest (0.80-1.05%) supersaturations measured. Overall, this multi-component aerosol model based on size distributions and size-resolved hygroscopicity yields reasonable predictions of the humidity-dependent optical properties and CCN spectra of the aerosol
Spatial distribution of surface EMG on trapezius and lumbar muscles of violin and cello players in single note playing
Musicians activate their muscles in different patterns, depending on their posture, the instrument
being played, and their experience level. Bipolar surface electrodes have been used in the past to
monitor such activity, but this method is highly sensitive to the location of the electrode pair. In this
work, the spatial distribution of surface EMG (sEMG) of the right trapezius and right and left erector
spinae muscles were studied in 16 violin players and 11 cello players. Musicians played their
instrument one string at a time in sitting position with/without backrest support. A 64 sEMG
electrode (16x4) grid, 10mm inter-electrode distance (IED), was placed over the middle and lower
trapezius (MT and LT) of the bowing arm. Two 16x2 electrode grids (IED=10mm) were placed on
the left and right erector spinae muscles. Subjects played each of the four strings of the instrument
either in large (1bow/s) or detaché tip/tail (8bows/s) bowing in two sessions (two days). In each of
two days, measurements were repeated after half an hour of exercise to see the effect of exercise
on the muscle activity and signal stability. A “muscle activity index” (MAI) was defined as the
spatial average of the segmented active region of the RMS map. Spatial maps were automatically
segmented using the watershed algorithm and thresholding. Results showed that, for violin
players, sliding the bow upward from the tip toward the tail results in a higher MAI for the trapezius
muscle than a downward bow. On the contrary, in cello players, higher MAI is produced in the tail
to tip movement. For both instruments, an increasing MAI in the trapezius was observed as the
string position became increasingly lateral, from string 1 (most medial) toward string 4 (most
lateral). Half an hour of performance did not cause significant differences between the signal
quality and the MAI values measured before and after the exercise. The MAI of the left and right
erector spinae was smaller in the case of backrest support, especially for violin players. Back
muscles of violin and cello players were activated asymmetrically, specifically in fast movements
(detaché tip/tail). These findings demonstrate the sensitivity and stability of the technique and
justify more extensive investigation following this proof of concept
Neisseria meningitidis: pathogenetic mechanisms to overcome the human immune defences
Neisseria meningitidis is hosted only by humans and colonizes the nasopharynx; it survives in the human body by reaching an equilibrium with its exclusive host. Indeed, while cases of invasive disease are rare, the number of asymptomatic Neisseria menin- gitides carriers is far higher. The aim of this paper is to sum- marize the current knowledge of survival strategies of Neisseria meningitides against the human immune defences. Neisseria meningitidis possesses a variety of adaptive character- istics which enable it to avoid being killed by the immune system, such as the capsule, the lipopolysaccharide, groups of proteins that block the action of the antimicrobial proteins (AMP), pro- teins that inhibit the complement system, and components that prevent both the maturation and the perfect functioning of phago- cytes. The main means of adhesion of Neisseria meningitides to the host cells are Pili, constituted by several proteins of whom the most important is Pilin E. Opacity-associated proteins (Opa) and (Opc) are two proteins that make an important contribution to the process of adhesion to the cell. Porins A and B contribute to neisserial adhesion and penetration into the cells, and also inhibit the complement system. Factor H binding protein (fhbp) binds factor H, allowing the bac- teria to survive in the blood. Neisserial adhesin A (NadA) is a minor adhesin that is expressed by 50% of the pathogenic strains. NadA is known to be involved in cell adhesion and invasion and in the induction of proinflam- matory cytokines. Neisserial heparin binding antigen (NHBA) binds heparin, thus increasing the resistance of the bacterium in the serum. The full article is free available on www.jpmh.or
Assessment and prevention of radioactive risk due to 222Radon on university premises in Genoa, Italy
From October 2004 to September 2005, Radon222 activity inhigh-risk indoor spaces used by employees and students at theUniversity of Genoa was measured with CR-39 nuclear trackdetectors. The mean concentration in winter (78.9 Bq/m3 ± 74.92 S.D.) was low in relation to the microenvironment considered. When data were broken down by type and location ofthe spaces, no significant differences were found, despite thefact that the Genoa conurbation lies on soil of variable geological composition. The dose absorbed by employees was 0.42 mSv/year, with a relative risk of 4.2/1000 cases of Radonrelated lung cancer. The dose absorbed by students was 0.28mSv/year, with a relative risk of 2.5/1000 cases of Radonrelated lung cancer. The level of radon activity detected neverexceeded the limit of 500 Bq/m3 established by Italian law.Nevertheless, the value of the compound uncertainty indexsuggested that the real level of Radon contamination couldhave exceeded 400 Bq/m3 in selected spaces, a value requiring annual concentration tests
Inferior alveolar nerve impairment after mandibular sagittal split osteotomy: an analysis of spontaneous recovery pattern observed in 60 patients
Sensory impairment after bilateral sagittal split osteotomy (BSSO) due to inferior alveolar nerve (IAN) lesions may be either temporary or permanent and either complete or partial. The aim of this prospective study is to evaluate, by means of objective sensory testing, IAN sensory disturbances development in patients who underwent BSSO.IAN sensory disturbances development at the first week, fourth week, sixth month, and twelfth month of follow-up review in a group of 60 patients who underwent BSSO from January 1, 1998, to July 31, 1999, at the Maxillofacial Surgery Department of the "La Sapienza" University of Rome. The 60 patients were examined in the presurgical period; the IAN functionality regarding thermal sensibility, nociception, and two-point discrimination, was assessed at follow-up in 120 sides. In our study the highest rate of spontaneous recovery of the entire IAN functionality was observed at the sixth month. This finding witnesses how neuropraxia and axonotmesis give a spontaneous recovery that most frequently occurs within 6 months from surgery, independently from age and sex of the patient. The persistence of anesthesia over 12 months could be a sign of neurotmesis
HPV vaccination and allocative efficiency: regional analysis of the costs and benefits with the bivalent AS04-adjuvanted vaccine, from the perspective of public health, for the prevention of cervical cancer and its pre-cancerous lesions
Introduction: by means of the decisions on whether to introduce the HPV vaccination, Public Health has already established the importance of associating the vaccination strategy to the policy of secondary prevention. The screening + vaccination strategy is more effective than the two methods taken individually. In support of this combined strategy and in order to make available per each region concrete elements for their regional planning, an assessment has been made, which also takes into account the effect of cross-protection regarding high-risk strains not contained in both vaccines, bivalent and quadrivalent, and more frequently responsible for pre-cancerous lesions and cervical cancer (CCU). This analysis evaluates the costs and benefits of screening + vaccination strategy in a 12-year-old female cohort. Furthermore, the paper provides results that may be useful to assess the opportunity to extend the vaccination to a second cohort of 24-25-year-old women. The analysis is preceded by a brief summary of CCU epidemiology available data, public health policies that give precise guidelines for vaccination strategies and analytical tools suitable to support public policy makers to efficiently allocate resources. Methods: two different models were used for two regional analyses.The vaccines may have different sustained- and cross-protection levels against non-vaccine oncogenic HPV-types. In the first analysis, a prevalence-based model estimated the potential net difference in HPV-related lesions (abnormal pap smear, cervical intraepithelial neoplasia (CIN), cervical cancer (CC) and genital warts (GW)) and associated costs generated by the two vaccines. Vaccine efficacy rates were based on published data for each vaccine. Lifetime vaccine efficacy was assumed. Results are reported over one year after reaching a steady state. Incidence and treatment costs were obtained from Italian and European sources. We also performed a cost-effectiveness analysis with a Markov model for each Italian region, previously described and successfully adapted to the national scenario. The analysis compares the HPV vaccination of a single cohort (12-year-old females) with a multiple cohort (12- + 25-year-old girls). Resource use was based on a standard therapeutic path applied to all regions. However we quantified the impact of the so-called "decentralization progress" by collecting regional data on: pap test coverage, tariffs for treatments, and cost of the vaccination course. Results: the results are set out in 21 regional reports. Conclusions: in the Italian scenario, characterized by decentralization and local autonomy, a further level of detail is essential in order to describe the specific local settings and implications of a new health intervention. The results show that the vaccination on a multiple cohort is more effective than a single cohort. Indeed, a major number of pre-cancerous lesions, cases of cancer, and related deaths are avoided. In a period of sharp decline in the health budget, investment in prevention seems to be the most reasonable choice in view of avoiding in the medium term pre-cancerous and cancerous lesions generating a significant expense. Our analysis places the extent of HPV vaccination among the measures that the regional decision-makers should put in place to maximize the efficiency of scarce resource
Histogram-less LiDAR through SPAD response linearization
We present a new method to acquire the 3D information from a SPAD-based
direct-Time-of-Flight (d-ToF) imaging system which does not require the
construction of a histogram of timestamps and can withstand high flux operation
regime. The proposed acquisition scheme emulates the behavior of a SPAD
detector with no distortion due to dead time, and extracts the Tof information
by a simple average operation on the photon timestamps ensuring ease of
integration in a dedicated sensor and scalability to large arrays. The method
is validated through a comprehensive mathematical analysis, whose predictions
are in agreement with a numerical Monte Carlo model of the problem. Finally, we
show the validity of the predictions in a real d-ToF measurement setup under
challenging background conditions well beyond the typical pile-up limit of 5%
detection rate up to a distance of 3.8 m
- …