164 research outputs found
Exploring the receptor origin of vibration-induced reflexes
STUDY DESIGN: An experimental design. OBJECTIVES: The aim of this study was to determine the latencies of vibration-induced reflexes in individuals with and without spinal cord injury (SCI), and to compare these latencies to identify differences in reflex circuitries. SETTING: A tertiary rehabilitation center in Istanbul. METHODS: Seventeen individuals with chronic SCI (SCI group) and 23 participants without SCI (Control group) were included in this study. Latency of tonic vibration reflex (TVR) and whole-body vibration-induced muscular reflex (WBV-IMR) of the left soleus muscle was tested for estimating the reflex origins. The local tendon vibration was applied at six different vibration frequencies (50, 85, 140, 185, 235, and 265âHz), each lasting for 15âs with 3-s rest intervals. The WBV was applied at six different vibration frequencies (35, 37, 39, 41, 43, and 45âHz), each lasting for 15âs with 3-s rest intervals. RESULTS: Mean (SD) TVR latency was 39.7 (5.3)âms in the SCI group and 35.9 (2.7)âms in the Control group with a mean (95% CI) difference of -3.8 (-6.7 to -0.9)âms. Mean (SD) WBV-IMR latency was 45.8 (7.4)âms in the SCI group and 43.3 (3.0)âms in the Control group with a mean (95% CI) difference of -2.5 (-6.5 to 1.4)âms. There were significant differences between TVR latency and WBV-IMR latency in both the groups (mean (95% CI) difference; -6.2 (-9.3 to -3.0)âms, pâ=â0.0001 for the SCI group and -7.4 (-9.3 to -5.6)âms, pâ=â0.011 for Control group). CONCLUSIONS: The results suggest that the receptor of origin of TVR and WBV-IMR may be different
Blind competition on the numerical simulation of continuous shallow steelâfiber reinforced concrete beams failing in bending
This article describes the second blind simulation competition (BSC) organized
by the fib WG 2.4.1, which aims to assess the predictive performance of models
based on the finite element method (FEM) for the analysis and design of fiber
reinforced concrete (FRC) structures. Slabs supported on columns or piles have
becoming competitive applications for FRC due to the technical and economic
benefits may be obtained by combining properly the fiber reinforcement mechanisms to those provided by conventional reinforcement placed, as a strip, in
the alignment of columns/piles. Therefore, a representative zone of this structural system, namely a hybrid fiber reinforced concrete (R/FRC) shallow beam,
is chosen in this BSC to show the potentialities of FRC in these types of applications, as well as to assess the predictive performance of FEM-based computational models on the design verification at serviceability and at ultimate limit
state conditions (SLS and ULS, respectively). Two statically indeterminateshallow beams of two equal spans were tested up to their failure, by recording
the applied loads, the strains in the conventional reinforcements and in the
FRC of the critical zones of the structure. By using digital image correlation,
the average crack width at the level of the flexural reinforcements was
recorded. The participants had to predict these results by receiving information
about the mechanical properties of the materials, the geometry of the prototypes and their loading and support conditions. In this article, the rules and
the results of this 2nd BSC competition are presented, and the data obtained
experimentally is thoroughly analyzed.PID2021-125553NB-I00; PTDC/ECI-EST/6300/202
Does type of hospital ownership influence physicians' daily work schedules? An observational real-time study in German hospital departments
Background: During the last two decades the German hospital sector has been engaged in a constant process of transformation. One obvious sign of this is the growing amount of hospital privatization. To date, most research studies have focused on the effects of privatization regarding financial outcomes and quality of care, leaving important organizational issues unexplored. Yet little attention has been devoted to the effects of privatization on physicians' working routines. The aim of this observational real-time study is to deliver exact data about physicians' work at hospitals of different ownership. By analysing working hours, further impacts of hospital privatization can be assessed and areas of improvement identified.
Methods: Observations were made by shadowing 100 physicians working in private, for-profit or non-profit as well as public hospital departments individually during whole weekday shifts in urban German settings. A total of 300 days of observations were conducted. All working activities were recorded, accurate to the second, by using a mobile personal computer.
Results: Results have shown significant differences in physicians' working activities, depending on hospital ownership, concerning working hours and time spent on direct and indirect patient care.
Conclusion: This is the first real-time analysis on differences in work activities depending on hospital ownership. The study provides an objective insight into physicians' daily work routines at hospitals of different ownership, with additional information on effects of hospital privatization
Razvoj i in vitro vrednovanje puferiranog bioadhezivnog vaginalnog gela za mijeĆĄane vaginalne infekcije
An acid buffering bioadhesive vaginal (ABBV) gel was developed for the treatment of mixed vaginal infections. Different bioadhesive polymers were evaluated on the basis of their bioadhesive strength, stability and drug release properties. Bioadhesion and release studies showed that guar gum, xanthan gum and hydroxypropylmethylcellulose K4M formed a good combination of bioadhesive polymers to develop the ABBV gel. Mono sodium citrate was used as an acid buffering agent to provide acidic pH (4.4). The drugs clotrimazole (antifungal) and metronidazole (antiprotozoal as well as antibacterial) were used in the formulation along with Lactobacillus spores to treat mixed vaginal infections. The ex vivo retention study showed that the bioadhesive polymers hold the gel for 12-13 hours inside the vaginal tube. Results of the in vitro antimicrobial study indicated that the ABBV gel had better antimicrobial action than the commercial intravaginal drug delivery systems and retention was prolonged in an ex vivo retention experiment.U radu je opisan razvoj puferiranog biodhezivnog vaginalnog (acid buffering bioadhesive vaginal, ABBV) gela za terapiju mijeĆĄanih vaginalnih infekcija. Ispitani su razliÄiti bioadhezivni polimeri procijenjena su njihova bioadhezivna svojstva, stabilnost i sposobnost oslobaÄanja ljekovite tvari. Guar guma, ksantan guma i hidroksipropilmetilceluloza K4M tvore dobru kombinaciju za ABBV gel. Mono natrijev citrat upotrebljen je kao puferirajuÄa tvar koja omoguÄava blago kiseli pH (4,4), a kao ljekovite tvari upotrebljeni su klotrimazol (antimikotik) i metronidazol (antiprotozoik i antibakterijsko sredstvo), zajedno sa sporama Lactobacillus. Pripravci su upotrebljeni u terapiji mijeĆĄanih vaginalnih infekcija. Pokusi ex vivo pokazali su da se bioadhezivni gel zadrĆŸava u vagini 12-13 sati. Rezultati in vitro ispitivanja ukazuju na to da ABBV gel ima bolje antibakterijsko djelovanje i dulje zadrĆŸavanje od intravaginalnog sustava koji je dostupan na trĆŸiĆĄtu
Stereotaxical Infusion of Rotenone: A Reliable Rodent Model for Parkinson's Disease
A clinically-related animal model of Parkinson's disease (PD) may enable the elucidation of the etiology of the disease and assist the development of medications. However, none of the current neurotoxin-based models recapitulates the main clinical features of the disease or the pathological hallmarks, such as dopamine (DA) neuron specificity of degeneration and Lewy body formation, which limits the use of these models in PD research. To overcome these limitations, we developed a rat model by stereotaxically (ST) infusing small doses of the mitochondrial complex-I inhibitor, rotenone, into two brain sites: the right ventral tegmental area and the substantia nigra. Four weeks after ST rotenone administration, tyrosine hydroxylase (TH) immunoreactivity in the infusion side decreased by 43.7%, in contrast to a 75.8% decrease observed in rats treated systemically with rotenone (SYS). The rotenone infusion also reduced the DA content, the glutathione and superoxide dismutase activities, and induced alpha-synuclein expression, when compared to the contralateral side. This ST model displays neither peripheral toxicity or mortality and has a high success rate. This rotenone-based ST model thus recapitulates the slow and specific loss of DA neurons and better mimics the clinical features of idiopathic PD, representing a reliable and more clinically-related model for PD research
Measuring quality of life in Duchenne muscular dystrophy : a systematic review of the content and structural validity of commonly used instruments
Duchenne muscular dystrophy (DMD) is an inherited X-linked neuromuscular disorder. A number of questionnaires are available to assess quality of life in DMD, but there are concerns about their validity. This systematic review aimed to appraise critically the content and structural validity of quality of life instruments for DMD. Five databases (EMBASE, MEDLINE, CINAHL, PsycINFO, and Cochrane Library) were searched, with supplementary searches in Google Scholar. We included articles with evidence on the content and/or structural validity of quality of life instruments in DMD, and/or instrument development. Evidence was evaluated against the Consensus-based Standards for the selection of health Measurement INstruments (COSMIN) criteria. Fifty five articles featured a questionnaire assessing quality of life in DMD. Forty instruments were extracted and 26 underwent assessment. Forty-one articles contained evidence on content or structural validity (including 37 development papers). Most instruments demonstrated low quality evidence and unsatisfactory or inconsistent validity in DMD, with the majority not featuring direct validation studies in this population. Only KIDSCREEN received an adequate rating for instrument design and a satisfactory result for content validity based on its development, yet, like the majority of PROMs, the measure has not been directly validated for use in DMD. Further research is needed on the validity of quality of life instruments in DMD, including content and structural validity studies in this population
Brain-Performance Correlates of Working Memory Retrieval in Schizophrenia: A Cognitive Modeling Approach
Correlations of cognitive functioning with brain activation during a sternberg item recognition paradigm (SIRP) were investigated in patients with schizophrenia and in healthy controls studied at 8 sites. To measure memory scanning times, 4 response time models were fit to SIRP data. The best fitting model assumed exhaustive serial memory scanning followed by self-terminating memory search and involved one intercept parameter to represent SIRP processes not contributing directly to memory scanning. Patients displayed significantly longer response times with increasing memory load and differed on the memory scanning, memory search, and intercept parameters of the best fitting probability model. Groups differed in the correlation between the memory scanning parameter and linear brain response to increasing memory load within left inferior and left middle frontal gyrus, bilateral caudate, and right precuneus. The pattern of findings in these regions indicated that high scanning capacity was associated with high neural capacity among healthy subjects but that scanning speed was uncoupled from brain response to increasing memory load among schizophrenia patients. Group differences in correlation of the best fitting model's scanning parameter with a quadratic trend in brain response to increasing memory load suggested inefficient or disordered patterns of neural inhibition among individuals with schizophrenia, especially in the left perirhinal and entorhinal cortices. The results show at both cognitive and neural levels that disordered memory scanning contributes to deficient SIRP performance among schizophrenia patients
European candidaemia is characterised by notable differential epidemiology and susceptibility pattern: Results from the ECMM Candida III study.
The objectives of this study were to assess Candida spp. distribution and antifungal resistance of candidaemia across Europe. Isolates were collected as part of the third ECMM Candida European multicentre observational study, conducted from 01 to 07-07-2018 to 31-03-2022. Each centre (maximum number/country determined by population size) included âŒ10 consecutive cases. Isolates were referred to central laboratories and identified by morphology and MALDI-TOF, supplemented by ITS-sequencing when needed. EUCAST MICs were determined for five antifungals. fks sequencing was performed for echinocandin resistant isolates. The 399 isolates from 41 centres in 17 countries included C. albicans (47.1%), C. glabrata (22.3%), C. parapsilosis (15.0%), C. tropicalis (6.3%), C. dubliniensis and C. krusei (2.3% each) and other species (4.8%). Austria had the highest C. albicans proportion (77%), Czech Republic, France and UK the highest C. glabrata proportions (25-33%) while Italy and Turkey had the highest C. parapsilosis proportions (24-26%). All isolates were amphotericin B susceptible. Fluconazole resistance was found in 4% C. tropicalis, 12% C. glabrata (from six countries across Europe), 17% C. parapsilosis (from Greece, Italy, and Turkey) and 20% other Candida spp. Four isolates were anidulafungin and micafungin resistant/non-wild-type and five resistant to micafungin only. Three/3 and 2/5 of these were sequenced and harboured fks-alterations including a novel L657W in C. parapsilosis. The epidemiology varied among centres and countries. Acquired echinocandin resistance was rare but included differential susceptibility to anidulafungin and micafungin, and resistant C. parapsilosis. Fluconazole and voriconazole cross-resistance was common in C. glabrata and C. parapsilosis but with different geographical prevalence
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