222 research outputs found
Changing prices... changing times: evidence for Italy
This paper examines the process of adjustment of prices in Italy to determine whether nominal flexibility, measured by the frequency of price changes, has increased in the recent years of protracted stagnation and double-dip recession. The analysis is based on a large micro-level dataset of individual prices collected monthly by Istat from 2006 to 2013 for the Consumer Price Index. We find that both the percentage of prices adjusted monthly and the average size of the adjustment have risen significantly since the 1996-2001 period, in particular for downward changes. This greater flexibility is related in part to the spread of modern distribution structures. Our estimates further indicate that the recession has affected the price adjustment mechanism: for manufactures, price cuts have become larger and more frequent, while increases are more moderate; for services, both the frequency and the size of price increases have diminished
Hepatitis C virus infection and development of type 2 diabetes mellitus: Systematic review and meta-analysis of the literature
Type 2 diabetes mellitus (T2DM) is an endocrine disorder encompassing multifactorial mechanisms, and chronic hepatitis C virus infection (CHC) is a multifaceted disorder, associated with extrahepatic manifestations, including endocrinological disorders. CHC and T2DM are associated, but the subject remains controversial. We performed a systematic review and meta-analysis evaluating such association, searching on PubMed until February 29, 2016. Inclusion criteria were: 1) presence of at least one internal control group age- and gender-matched (non-hepatopathic controls; and/or hepatopathic, not HCV-positive, controls); 2) sufficient data to calculate odds ratio and relative risk. Exclusion criteria were: 1) literature reviews on the topic; 2) publications regarding special populations [human immunodeficiency virus and human T-lymphotropic virus-1 coinfections, hepatocellular carcinoma (HCC), post-transplantation DM, gender selection]; 3) no clear differentiation among HCV patients with CHC, cirrhosis or HCC. Data from each study were independently extracted by two reviewers and cross-checked by AA. Our systematic review returned 544 records, and 33 were included in our meta-analysis. HCV infection is associated with an increased risk of T2DM independently from the severity of the associated liver disease, in CHC and cirrhotic HCV patients. As expected T2DM risk is higher in cirrhotic HCV patients, than CHC, and the prevalence of HCV infection in T2DM patients is higher than in non-diabetic controls. Regarding HBV infection prevalence, no difference exists in diabetic and non-diabetic subjects. An unequivocal CHC and T2DM association was shown. A proactive, integrated approach to HCV and T2DM therapies should maximize benefits of both diseases treatment
Numerical simulations of fuel shape change and swirling flows in paraffin/oxygen hybrid rocket engines
The objective of this work is to describe and validate a numerical axisymmetric approach for the simulation of hybrid rocket engines (HREs), based on Reynolds-averaged NavierâStokes simulations, with sub-models for fluidâsurface interaction, radiation, chemistry, and turbulence. Fuel grain consumption is considered on both radial and axial directions and both axial and swirl injection of the oxidizer are simulated. Firing tests of two different paraffinâoxygen hybrid rockets are considered. First, a numerical rebuilding of fuel grain profile, regression rate and pressure for axial-injected HREs is performed, yielding a reasonable agreement with the available experimental data. Then, the same numerical model is applied to swirl-injected HREs and employed to analyze both the flowfield and the regression rate variation with swirl intensity. A validation of the model through the rebuilding of small-scale firing tests is also performed
Histomorphological and functional contralateral symmetry in the gastrocnemius muscles of the laboratory rat
It is usual in anatomical and physiological research to assess the effects of some intervention on extremities (e.g., training programmes or injury recovery protocols) using one muscle for the intervention and its contralateral as control. However, the existence of laterality (left-handedness or right-handedness) in athletes of different specialties is widely recognized. In rats, gastrocnemius is one of the muscles most widely used because of its importance in locomotion and high relative limb mass. Since we have not found studies reporting laterality assessment on the morphology and function in rat gastrocnemius, our study aimed to evaluate the fibre histochemical, morphometrical and muscle force contractile properties between right and left gastrocnemius of the laboratory rat. Fibre type proportion, fibre morphometrical measurements, muscle capillarization and muscle force properties were analysed in the right and left gastrocnemius of six male rats. No statistically significant differences (p=0.265) were found in gastrocnemius to body weight ratio (¿) between right (6.55±0.40) and left (6.49±0.40) muscles. The muscles analysed showed a great degree of heterogeneity in fibre type distribution, having three clearly distinguished regions named red, mixed and white. In the three regions, there were no statistical differences in fibre type proportions between right and left gastrocnemius, as is indicated by the p-values (from 0.203 to 0.941) obtained after running t-Student paired tests for each fibre type. When analysing fibre cross-sectional area, individual fibre capillarization and fibre circularity, no significant differences between right and left gastrocnemius in any of these morphometrical parameters were found in any muscle region or fibre type. Most of the p-values (70%) resulting from running t-Student paired tests were higher than 0.400, and the lowest p-value was 0.115. Seemingly, global capillary and fibre densities were not statistically different between right and left sides in all muscle regions with p-values ranging from 0.337 to 0.812. Force parameters normalized to gastrocnemius mass (mN·g-1) did not show any significant difference between right (PF=74.0±13.4, TF=219.4±13.0) and left (PF=70.9±10.7, TF=213.0±18.0) muscles with p=0.623 (PF) and p=0.514 (TF). Twitch time parameters (ms) also lacked significant differences between the two sides (CT: 43.4±8.6 vs 45.0±14.3, P=0.639; HRT: 77.6±15.0 vs 82.3±25.3, p=0.475). Finally, both muscles also showed similar (p=0.718) fatigue properties. We did find an absence of laterality at the morphological and functional levels, which raises the possibility of using right and left gastrocnemius muscles interchangeably for experimental designs where one muscle is used to analyse data after a physiological intervention and its contralateral muscle plays the control role, thus allowing unbiased paired comparisons to derive accurate conclusions
The Mayo ATTRâCM score versus other diagnostic scores and cardiac biomarkers in patients with suspected cardiac amyloidosis
Aims: Several scores were developed to help the diagnosis of cardiac amyloidosis (CA). The most recent one, being the Mayo transthyretin amyloidosis cardiomyopathy (ATTR-CM) score, was not externally validated. We compared the diagnostic performance of the ATTR-CM score with previous tools (increased wall thickness [IWT] score, AMYLoidosis Index [AMYLI] score, and cardiac biomarkers) in a cohort of patients evaluated for a suspicion of CA. Methods and results: We analysed 362 consecutive patients referred to a third-level centre for suspected CA. Overall, 132 (36%) had transthyretin CA (ATTR-CA), and 91 (25%) immunoglobulin light chain CA (AL-CA); CA was excluded in 139 (38%). ATTR-CM score had a good diagnostic performance to distinguish ATTR-CA from AL-CA or no CA, with an area under the curve (AUC) of 0.795 (95% confidence interval [CI] 0.747-0.842, p < 0.001), and ATTR-CA from no CA (AUC 0.822, 95% CI 0.774-0.871, p < 0.001). Results were consistent in both patients with preserved (AUC 0.787, 95% CI 0.726-0.848, p < 0.001), and reduced or mildly reduced ejection fraction (AUC 0.790, 95% CI 0.709-0.871, p < 0.001). The ATTR-CM score showed a better discrimination compared to IWT and AMYLI score to distinguish ATTR-CA from AL-CA or no CA (p = 0.002), but not to distinguish ATTR-CA from no CA (p = 0.270). Diagnostic accuracy was significantly higher for the ATTR-CM score as compared to the rule-in cut-off of high-sensitivity troponin T. Conclusion: The Mayo ATTR-CM score has a good performance in identifying patients with ATTR-CA, with also better discrimination power when compared to other scores and biomarkers
Experimental Investigation of a H2O2 Hybrid Rocket with Different Swirl Injections and Fuels
Hybrid rockets have very interesting characteristics like simplicity, reliability, safety, thrust modulation, environmental friendliness and lower costs, which make them very attractive for several applications like sounding rockets, small launch vehicles, upper stages, hypersonic test-beds and planetary landers. In recent years, advancements have been made to increase hybrid motor performance, and two of the most promising solutions are vortex injection and paraffin-based fuels. Moreover, both technologies can be also used to tailor the fuel regression rate, in the first case varying the swirl intensity, and in the second case with the amount and type of additives. In this way, it is possible not only to design high-performing hybrid motors, but also to adjust their grain and chamber geometries to different mission requirements, particularly regarding thrust and burning time. In this paper, the knowledge about these two technical solutions and their coupling is extended. Three sets of experimental campaigns were performed in the frame of the Italian Space Agency-sponsored PHAEDRA program. The first one investigated a reference paraffin fuel with axial and standard vortex injection. The second campaign tested vortex injection with low values of swirl numbers down to 0.5 with a conventional plastic fuel, namely polyethylene. Finally, the last campaign tested another, lower regressing, paraffin-based fuel with the same low swirl numbers as the second campaign
Centering Ability of ProTaper Next and WaveOne Classic in J-Shape Simulated Root Canals
Introduction. The aim of this study was to evaluate and compare the shaping and centering ability of ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland) and WaveOne Classic systems (Dentsply Maillefer) in simulated root canals. Methods. Forty J-shaped canals in resin blocks were assigned to two groups (n=20 for each group). Photographic method was used to record pre- and postinstrumentation images. After superimposition, centering and shaping ability were recorded at 9 different levels from the apex using the software Autocad 2013 (Autodesk Inc., San Rafael, USA). Results. Shaping procedures with ProTaper Next resulted in a lower amount of resin removed at each reference point level. In addition, the pattern of centering ability improved after the use of ProTaper Next in 8 of 9 measurement points. Conclusions. Within the limitations of this study, shaping procedures with ProTaper Next instruments demonstrated a lower amount of resin removed and a better centering ability than WaveOne Classic system
Normal aortic diameters within the Mexican population and the impact of gender and ethnicity
Background: There is a lack of studies describing the normal size of the aorta in Mexican population. Objective: To analyze aortic measurements in Mexican patients and to compared them with patients from five different countries. Methods: Measurements of the aorta were divided in Mexicans and controls. Comparisons between ethnicities and groups were performed using Mann Whitney rank sum test. Results: The registry included 166 patients, 106 (63.8%) were enrolled in Mexico and 60 (36.1%) in the control group. Mexican patients had smaller aortic diameters compared to the control group, at the level of the right renal artery ostium, inferior mesenteric artery, and aortic bifurcation. The Hispanic population had significantly smaller aortic diameters from the level of the celiac artery to the aortic bifurcation. Conclusion: The normal aortic diameters in the Mexican population are smaller compared to other countries.</p
Single nucleotide polymorphisms of ABCC5 and ABCG1 transporter genes correlate to irinotecan-associated gastrointestinal toxicity in colorectal cancer patients: a DMET microarray profiling study.
Abstract Recent findings have disclosed the role of UDP-glucuronosyltransferase (UGT) 1A1*28 on the haematological toxicity induced by irinotecan (CPT-11), a drug commonly used in the treatment of metastatic colorectal cancer (mCRC). We investigated the pharmacogenomic profile of irinotecan-induced gastrointestinal (GI) toxicity by the novel drug-metabolizing enzyme and transporter (DMET) microarray genotyping platform. Twenty-six mCRC patients who had undergone to irinotecan-based chemotherapy were enrolled in a case (patients experiencing > grade 3 gastrointestinal, (GI) toxicity) - control (matched patients without GI toxicity) study. A statistically significant difference of SNP genotype distribution was found in the case versus control group. The homozygous genotype C/C in the (rs562) ABCC5 gene occurred in 6/9 patients with GI toxicity versus 1/17 patients without GI toxicity (P=0.0022). The homozygous genotype G/G in the (rs425215) ABCG1 was found in 7/9 patients with GI toxicity versus 4/17 patients without GI toxicity (P=0.0135). The heterozygous genotype G/A in the 388G>A (rs2306283) OATP1B1/SLCO1B1 was found in 3/9 patients with grade > 3 GI toxicity versus 14/17 patients without GI toxicity (P=0.0277). DNA extracted from peripheral blood cells was genotyped by DMET Plus chip on Affymetrix array system. Genotype association was calculated by Fisher's exact test (two tailed) and relevant SNPs were further analyzed by direct sequencing. We have identified 3 SNPs mapping in ABCG1, ABCC5 and OATP1B1/SLCO1B1 transporter genes associated with GI toxicity induced by irinotecan in mCRC patients expanding the available knowledge of irinogenomics. The DMET microarray platform is an emerging technology for easy identification of new genetic variants for personalized medicine
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