GT2006-90596 VIBRATION REDUCTION INVESTIGATION OF A SQUEEZE FILM DAMPER WITH VALVULAR METAL RUBBER

ABSTRACT A new-style squeeze film damper with valvular metal rubber squeeze film ring (SFD/VMR) was designed to improve characteristics of the squeeze film force of the SFD. The immobile squeeze film ring of the SFD was replaced by the elastic squeeze film ring with the valvular metal rubber subassembly (VMR). When the unbalance force was smaller, the displacement of the journal changed little, and then the squeeze film force was smaller too, so as to the squeeze film ring of the SFD/VMR was nearly immobile. The working condition was similar with the SFD. When the unbalance force was larger, the displacement of the journal changed bigger, and then the squeeze film force rapidly increased, so as to the VMR deformed, which made the film thickness changed correspondingly, until it reached a balanceable state of the squeeze film force and elastic force of the VMR. Theoretical and experimental investigations showed that the SFD/VMR had optimal effect on reducing vibration, comparing with the SFD, because it could passively adjust the squeeze film clearance by taking advantage of the elastic deformation of the VMR. The SFD/VMR could control the squeeze film clearance in a suitable range, which made the characteristics of the squeeze film force of the SFD/VMR better than the SFD. The SFD/VMR could suppress the occurrence of the nonlinear vibration phenomenon markedly, such as bistable jump up

Transmission of H7N9 influenza virus in mice by different infective routes.

BackgroundOn 19 February 2013, the first patient infected with a novel influenza A H7N9 virus from an avian source showed symptoms of sickness. More than 349 laboratory-confirmed cases and 109 deaths have been reported in mainland China since then. Laboratory-confirmed, human-to-human H7N9 virus transmission has not been documented between individuals having close contact; however, this transmission route could not be excluded for three families. To control the spread of the avian influenza H7N9 virus, we must better understand its pathogenesis, transmissibility, and transmission routes in mammals. Studies have shown that this particular virus is transmitted by aerosols among ferrets.MethodsTo study potential transmission routes in animals with direct or close contact to other animals, we investigated these factors in a murine model.ResultsViable H7N9 avian influenza virus was detected in the upper and lower respiratory tracts, intestine, and brain of model mice. The virus was transmissible between mice in close contact, with a higher concentration of virus found in pharyngeal and ocular secretions, and feces. All these biological materials were contagious for naïve mice.ConclusionsOur results suggest that the possible transmission routes for the H7N9 influenza virus were through mucosal secretions and feces

The mouse and ferret models for studying the novel avian-origin human influenza A (H7N9) virus.

BackgroundThe current study was conducted to establish animal models (including mouse and ferret) for the novel avian-origin H7N9 influenza virus.FindingsA/Anhui/1/2013 (H7N9) virus was administered by intranasal instillation to groups of mice and ferrets, and animals developed typical clinical signs including body weight loss (mice and ferrets), ruffled fur (mice), sneezing (ferrets), and death (mice). Peak virus shedding from respiratory tract was observed on 2 days post inoculation (d.p.i.) for mice and 3-5 d.p.i. for ferrets. Virus could also be detected in brain, liver, spleen, kidney, and intestine from inoculated mice, and in heart, liver, and olfactory bulb from inoculated ferrets. The inoculation of H7N9 could elicit seroconversion titers up to 1280 in ferrets and 160 in mice. Leukopenia, significantly reduced lymphocytes but increased neutrophils were also observed in mouse and ferret models.ConclusionsThe mouse and ferret model enables detailed studies of the pathogenesis of this illness and lay the foundation for drug or vaccine evaluation

Noninvasive predictors of clinically significant portal hypertension in NASH cirrhosis: Validation of ANTICIPATE models and development of a lab-based model

Noninvasive predictors; Portal hypertension; CirrhosisPredictores no invasivos; Hipertensión portal; CirrosisPredictors no invasius; Hipertensió portal; CirrosiClinically significant portal hypertension (CSPH), defined as hepatic venous pressure gradient (HVPG) ≥ 10 mm Hg, identifies patients with compensated cirrhosis at a high risk of decompensation. However, HVPG is an invasive and nuanced method. The ANTICIPATE models, which include liver stiffness measurements by transient elastography (TE) and platelet count ± body mass index, are robust noninvasive surrogates of CSPH but required external validation in patients with nonalcoholic steatohepatitis (NASH) cirrhosis. Additionally, TE is not widely available worldwide. The aims of the study were: (1) to externally validate the ANTICIPATE models using baseline data from patients with compensated NASH cirrhosis screened/enrolled in a multicenter international randomized controlled trial; and (2) to develop and externally validate a model using only laboratory values. Regarding aim 1, both ANTICIPATE models showed good calibration and discrimination (area under the curve [AUC] > 0.8) in our cohort (n = 222). Regarding aim 2, a new lab-based model using the Fibrosis-4 index (FIB-4 [age, aspartate aminotransferase, alanine aminotransferase, platelet count]) plus serum albumin was developed. The discrimination in the training cohort (n = 309) was good (AUC of 0.78 [95% confidence interval [CI]:0.72–0.83]). It was then externally validated in a separate cohort of 245 patients with compensated NASH cirrhosis (AUC of 0.8 [95% CI: 0.75–0.86]). Given the difference in the prevalence of CSPH between training (74%) and validation (39%) cohorts, the model required an update of the baseline risk to achieve a good calibration. The updated model was named FIB4+. In conclusion, both ANTICIPATE models performed well in predicting the presence of CSPH in NASH cirrhosis. A model using FIB-4 plus albumin (FIB4+) can be used to predict CSPH where TE is not available.Supported by the Yale Liver Center, National Institutes of Health (P30 DK34989)

Moderators of Parent Training for Disruptive Behaviors in Young Children with Autism Spectrum Disorder

We conducted a 6 month, randomized trial of parent training (PT) versus a parent education program (PEP) in 180 young children (158 boys, 22 girls), ages 3-7 years, with autism spectrum disorder (ASD). PT was superior to PEP in decreasing disruptive and noncompliant behaviors. In the current study, we assess moderators of treatment response in this trial. Thirteen clinical and demographic variables were evaluated as potential moderators of three outcome variables: the Aberrant Behavior Checklist-Irritability subscale (ABC-I), Home Situations Questionnaire (HSQ), and Clinical Global Impressions-Improvement Scale (CGI-I). We used an intent-to-treat model and random effects regression. Neither IQ nor ASD severity moderated outcome on the selected outcome measures. Severity of Attention Deficit Hyperactivity Disorder (ADHD) and anxiety moderated outcomes on the ABC-I and HSQ. For instance, there was a 6.6 point difference on the ABC-I between high and low ADHD groups (p = .05) and a 5.3 point difference between high and low Anxiety groups (p = .04). Oppositional defiant disorder symptoms and household income moderated outcomes on the HSQ. None of the baseline variables moderated outcome on the CGI-I. That IQ and ASD symptom severity did not moderate outcome suggests that PT is likely to benefit a wide range of children with ASD and disruptive behavior

Natural ventilation reduces high TB transmission risk in traditional homes in rural KwaZulu-Natal, South Africa

Background: Transmission of drug susceptible and drug resistant TB occurs in health care facilities, and community and households settings, particularly in highly prevalent TB and HIV areas. There is a paucity of data regarding factors that may affect TB transmission risk in household settings. We evaluated air exchange and the impact of natural ventilation on estimated TB transmission risk in traditional Zulu homes in rural South Africa. Methods: We utilized a carbon dioxide decay technique to measure ventilation in air changes per hour (ACH). We evaluated predominant home types to determine factors affecting ACH and used the Wells-Riley equation to estimate TB transmission risk. Results: Two hundred eighteen ventilation measurements were taken in 24 traditional homes. All had low ventilation at baseline when windows were closed (mean ACH = 3, SD = 3.0), with estimated TB transmission risk of 55.4% over a ten hour period of exposure to an infectious TB patient. There was significant improvement with opening windows and door, reaching a mean ACH of 20 (SD = 13.1, p < 0.0001) resulting in significant decrease in estimated TB transmission risk to 9.6% (p < 0.0001). Multivariate analysis identified factors predicting ACH, including ventilation conditions (windows/doors open) and window to volume ratio. Expanding ventilation increased the odds of achieving ≥12 ACH by 60-fold. Conclusions: There is high estimated risk of TB transmission in traditional homes of infectious TB patients in rural South Africa. Improving natural ventilation may decrease household TB transmission risk and, combined with other strategies, may enhance TB control efforts

The effect of mixed La-Y doping on water resistance of phosphate glass

In this work, the effect of mixed La-Y doping on the water resistance of xLa2O3–(16-x)Y2O3–8Al2O3–10Na2O–66P2O5 (x = 0, 4, 8, 12, 16 mol%) glasses was studied. The glass structure, glass transition temperature (Tg), dc conductivity (σdc) and water resistance of glass were respectively characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC), electrochemical workstation and water resistance test. The results show that with the gradual replacement of Y2O3 by La2O3, the value of Q(2) (Q2 content as a percentage of the sum of Q1 and Q2 contents in glass structure) and water resistance characterized by mass loss per unit surface area indicate strong “mixed rare earth effect”. It is obvious that the change of glass structure causes water resistance of glass to vary nonlinearly and exhibit a positive deviation from linearity. The results can provide some useful information for tailoring the chemical durability of glass by mixed rare earth doping