scholarly journals Exploring the Potential to Repurpose Flexible Moulded Polyurethane Foams as Acoustic Insulators

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 163
Author(s):  
Enikő Mester ◽  
Dániel Pecsmány ◽  
Károly Jálics ◽  
Ádám Filep ◽  
Miklós Varga ◽  
...  
Keyword(s):  
Foam Cell ◽  
Absorption Capacity ◽  
Polyurethane Foams ◽  
Sound Insulation ◽  
Acoustic Damping ◽  
Polyurethane Waste ◽  
Cell Structures ◽  
Frequent Use ◽  
Before And After

Polyurethane flexible foams are widely used for a variety of applications to improve comfort and durability. Their long-term frequent use inevitably leads to the generation of waste that needs to be treated. The recycling and reuse of polyurethane waste are essential to achieve an environmentally friendly economy. The present study investigates the potential to reuse and repurpose flexible polyurethane foam from automotive seat cushion waste materials. Flexible foams were prepared with different hardnesses using isocyanate–polyol ratios between 0.8 and 1.2 NCO-index. Dry heat aging tests were performed to mimic the long-term usage of the materials. The decrease in compressive strength was compared with the change in acoustic damping properties before and after the aging tests using an acoustic tube, and the change in foam cell structures was also analyzed by micro-CT. On the basis of the results obtained, although the foam systems are no longer suitable to be used as seat cushions due to aging, they can still be used as sound insulation materials within a given frequency range, as their sound absorption capacity is suitable for such purpose.

Nanomaterials in PU Foam for Enhanced Sound Absorption at Low Frequency Region

2014 ◽  
Vol 938 ◽  
pp. 170-175 ◽  
Author(s):  
R. Gayathri ◽  
R. Vasanthakumari
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Foam Cell ◽  
Research Work ◽  
Low Frequency ◽  
Absorption Capacity ◽  
Polyurethane Foams ◽  
Sound Absorption Coefficient ◽  
Enhanced Absorption ◽  
Pu Foam

Lot of research is going on to develop materials suitable for absorbing sound and reducing noise. By virtue of their superior vibration damping capability and attractive characteristics such as visco elasticity, simple processing and commercial availability, polyurethane foams are extensively applied not only in automotive seats but also in various acoustical parts. However, the sound absorption coefficient of polyurethane foams is high (0.8 1.0) in high frequencies in the range 300 to 10000Hz while it is found to be low (0 to 0.5) at low frequencies (10 to 200 Hz). In this study new polyurethane based porous composites were synthesized by in situ foam rising polymerization of polyol and diisocyanate in the presence of fillers such as nanosilica (NS) and nanoclay (NC). The effect of these fillers at various concentrations up to 2% was studied for sound absorption characteristics in the frequency range 100-200Hz. Sound absorption coefficient was determined using standing wave impedance tube method. The sound absorption coefficient of filled PU foams increases from 0.5 to 0.8 with frequency increase from 100 to 200 Hz at higher content of the nanofillers employed. This research work is further extended to study the sound absorption capacity of unfilled PU foam with varying thickness and also hybrid foams with woven glass (GFC) and polyester cloth (PEC). The unfilled foam with 60mm of thickness gives sound absorption value same as that of 15mm of filled foam. Further enhanced absorption value is achieved with PU/NS-GFC hybrid. The results obtained are explained based on the porosity of composite structure and foam cell size.Key words Polyurethane foam, sound absorption coefficient, nanosilica, nanoclay, low frequency sound.

The role of probiotics in correction of microbiocenosis and cytokine balance of the oral cavity of patient with chronic inflammatory disease of periodont

2020 ◽  
Vol 25 (4) ◽  
pp. 323-330
Author(s):  
E. S. Ovcharenko ◽  
V. V. Erichev ◽  
S. I. Risovannij ◽  
T. V. Aksenova ◽  
S. V. Melekhov ◽  
...  
Keyword(s):  
Oral Cavity ◽  
Periodontal Diseases ◽  
Treatment Protocol ◽  
Chronic Inflammatory Disease ◽  
Oral Microbiome ◽  
Comprehensive Treatment ◽  
Local Immunity ◽  
Treatment Techniques ◽  
Before And After

Relevance. A long-term inflammation in the oral cavity, unreasonable treatment of periodontal patients with antibiotics cause imbalance between certain types of fungal-bacterial associations accompanied by oral dysbiosis and change of local immune status. So, development and application of new comprehensive diagnosis and treatment techniques in periodontal patients, use of products for correction of microbiota and local immunity are a current and a long-term task. Purpose is to optimize the comprehensive treatment protocol of inflammatory periodontal diseases by introducing probiotics and evaluation of oral microbiome and cytokine profile.Materials and methods. 140 patients were examined. Of these 60 patients had chronic generalized plaque-induced gingivitis and 60 patients suffered from moderate chronic generalized periodontitis. Bacterial and fungal microbiome was assessed and the host immune response was evaluated in all patients before and after the treatment. Half of the patients were treated conventionally and the other half were treated according to a modified scheme: probiotic “Bifidumbacterin Forte” was added.Results. A large number of yeast-like fungi Candida and commensal bacteria were detected in periodontal pockets of patients with chronic generalized plaque-induced gingivitis and moderate chronic generalized periodontitis. That correlates with a significant increase of pro-inflammatory cytokines (TNF-α, IL—8), decrease of concentration of INF-γ and increase of antiinflammatory cytokine IL-4.Conclusion. Changes in clinical, microbiological and immunological values during a modified combination therapy with a probiotic and during a conventional treatment demonstrated that effectiveness of treatment of chronic gingivitis and chronic periodontitis increased by 40% and 37% respectively.

REPEATED LONG-TERM SPACE FLIGHTS: PROTEOMIC INVESTIGATIONS OF COSMONAUTS' BLOOD

2020 ◽  
Vol 54 (5) ◽  
pp. 15-22
Author(s):  
I.M. Larina ◽  
◽  
D.N. Kashirina ◽  
K.S. Kireev ◽  
A.I. Grigoriev ◽  
...  
Keyword(s):  
Bone Structure ◽  
Space Station ◽  
The Body ◽  
Coagulation Cascade ◽  
Chemical Components ◽  
Blood Proteins ◽  
Blood Indices ◽  
Before And After ◽  
Biochemical Indices

We performed the first ever comparative analysis of modifications in the proteome, ionogram and some other blood plasma biochemical indices of 18 male cosmonauts (44 ± 6 years of age) before and after maiden or repeated long-term missions to the Russian segment of the International space station (ISS RS). Levels of proteins, substrates and ions as well as chemical components were measured using the LC-MS-based proteomics and routine biochemical techniques. A total of 256 to 281 indices were investigated with the methods of descriptive statistic, regression analysis, and access to bioinformatics resources. It was shown that blood indices recovery from the maiden and repeated missions reflects changes in the body systems and goes at a various speed. The results of measurements made prior to launch and on day 7 after landing are dependent on the number of missions. The bioinformatics techniques showed that after maiden missions both the mediator proteins of alkaline phosphatase (AP) and blood proteins with reliably changing concentrations are associated with the bio-processes including stress, metabolism and DNA reparation, apoptosis, catabolism and proteolysis. During early re-adaptation from repeated missions the AP level was affected by bone remodeling, phosphorylation, angiogenesis and coagulation cascade suggesting a distinct and urgent trigger of the processes of bone structure and mineralization.

scholarly journals Feasibility and Enjoyment of Exercise Video Games in Older Adults

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 559-559
Author(s):  
Sara Freed ◽  
Briana Sprague ◽  
Lesley Ross
Keyword(s):  
Older Adults ◽  
Video Games ◽  
Game Design ◽  
Long Term Effects ◽  
Short Term ◽  
Qualitative And Quantitative ◽  
Before And After ◽  
Xbox Kinect ◽  
Game Developers

Abstract Interventions using exercise video games, or exergames, have shown short-term cognitive and physical benefits to older adults, though long-term effects are less promising. Enjoyment of exergames may promote exergame use after the intervention period, though little work has examined older adults’ views of exergames before and after gameplay experience. We invited 20 older adults between 65 and 84 years of age (M=73.30, SD=5.95) to play two Xbox Kinect games, Just Dance and Kinect Sports Rivals, for twenty minutes. In our presentation, we will present qualitative and quantitative findings of this pilot study, including findings that older adults reported that they were not likely to play similar exergames in the future and that they did not find the exergames to be more fun compared to other ways of exercising. We will discuss implications for game design and research relevant to game developers, manufacturers, and researchers. Part of a symposium sponsored by Technology and Aging Interest Group.

scholarly journals Endoscopically controlled surgery with open hemilaminectomy for the treatment of intradural extramedullary tumors: an operative technique and short-term outcomes of 20 consecutive cases

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Xiaorong Yan ◽  
Huiqing Wang ◽  
Cai Li ◽  
Yuanxiang Lin ◽  
Lin Lin ◽  
...  
Keyword(s):  
Surgical Technique ◽  
Spinal Deformity ◽  
Tumor Recurrence ◽  
Clinical Symptoms ◽  
Short Term ◽  
Before And After ◽  
Intradural Extramedullary ◽  
Controlled Surgery

Abstract Background To present a surgical technique for the treatment of intradural extramedullary (IDEM) tumors by using endoscopically controlled surgery with open hemilaminectomy technique. Methods In this study, 20 patients with 22 IDEM tumors were enrolled. An endoscopically controlled surgery with open hemilaminectomy was employed to remove the tumors. Data related to clinical symptoms and medical images before and after surgery were collected for perioperative evaluation and follow-up analysis. Results All the tumors in 20 patients were well removed. The clinical symptoms were significantly reduced in all the patients as well. The short-term follow-up data showed that there was no tumor recurrence or spinal deformity. Conclusion The endoscopically controlled surgery with open hemilaminectomy technique provided favorable exposure and satisfactory resection to the IDEM tumors. It may be an effective surgical method for treating IDEM tumors. Larger samples and longer follow-up data are needed to verify its long-term effectiveness.

scholarly journals The Demerger Impact upon Sustainable Development of Economic Entities: Evidence from Romania

2021 ◽  
Vol 13 (15) ◽  
pp. 8316
Author(s):  
Camelia Mirela Baba ◽  
Constantin Duguleană ◽  
Marius Sorin Dincă ◽  
Liliana Duguleană ◽  
Gheorghița Dincă
Keyword(s):  
Sustainable Development ◽  
Business Strategies ◽  
The Sustainable Development ◽  
Ex Post ◽  
Before And After ◽  
Almost All ◽  
The Impact ◽  
Profitability Ratios ◽  
Positive Effect

The Covid-19 induced economic crisis has significantly affected almost all businesses from nearly every sector, causing severe financial problems, lack of cash assets, and decrease of revenues. In this context, the economic entities were forced to look for adjustment and rescue solutions of their activities. One possible solution for the recovery and reorganization of economic entities’ activities is demerger. This paper evaluates the impact of demerger upon the sustainable development of economic entities in terms of economic efficiency and financial performances. To achieve this goal, a statistical analysis of profitability ratios before and after the demerger, as well as a structural analysis of 268 demerger projects for the April 2012–April 2021 period, were performed. The results attest there are no significant differences between the ex-ante and ex-post financial performances. However, demerger seems to have a positive effect upon analyzed companies helping them to overcome economic hardships, rethink their business strategies, and continue their activity in the medium and long-term time horizon.

Long-term trajectories of decline in cognition and daily functioning before and after stroke

2021 ◽  
pp. jnnp-2021-326043
Author(s):  
Alis Heshmatollah ◽  
Lisanne J. Dommershuijsen ◽  
Lana Fani ◽  
Peter J. Koudstaal ◽  
M. Arfan Ikram ◽  
...  
Keyword(s):  
Continuous Monitoring ◽  
Mini Mental State Examination ◽  
Functional Decline ◽  
Population Based ◽  
Daily Functioning ◽  
Linear Mixed Effects ◽  
Before And After ◽  
State Examination

ObjectiveAlthough knowledge on poststroke cognitive and functional decline is increasing, little is known about the possible decline of these functions before stroke. We determined the long-term trajectories of cognition and daily functioning before and after stroke.MethodsBetween 1990 and 2016, we repeatedly assessed cognition (Mini-Mental State Examination (MMSE), 15-Word Learning, Letter–Digit Substitution, Stroop, Verbal Fluency, Purdue Pegboard) and basic and instrumental activities of daily living (BADL and IADL) in 14 712 participants within the population-based Rotterdam Study. Incident stroke was assessed through continuous monitoring of medical records until 2018. We matched participants with incident stroke to stroke-free participants (1:3) based on sex and birth year. Trajectories of cognition and daily functioning of patients who had a stroke 10 years before and 10 years after stroke and the corresponding trajectories of stroke-free individuals were constructed using adjusted linear mixed effects models.ResultsDuring a mean follow-up of 12.5±6.8 years, a total of 1662 participants suffered a first-ever stroke. Patients who had a stroke deviated from stroke-free controls up to 10 years before stroke diagnosis in cognition and daily functioning. Significant deviations before stroke were seen in scores of MMSE (6.4 years), Stroop (5.7 years), Purdue Pegboard (3.8 years) and BADL and IADL (2.2 and 3.0 years, respectively).ConclusionPatients who had a stroke have steeper declines in cognition and daily functioning up to 10 years before their first-ever stroke compared with stroke-free individuals. Our findings suggest that accumulating intracerebral pathology already has a clinical impact before stroke.

scholarly journals Physical Comorbidities and Depression in Recent and Long-Term Adult Cancer Survivors: NHANES 2007–2018

Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3368
Author(s):  
Dafina Petrova ◽  
Andrés Catena ◽  
Miguel Rodríguez-Barranco ◽  
Daniel Redondo-Sánchez ◽  
Eloísa Bayo-Lozano ◽  
...  
Keyword(s):  
Cancer Survivors ◽  
Cancer Patients ◽  
Cancer Diagnosis ◽  
Depression Symptoms ◽  
Depression Risk ◽  
Adult Cancer Survivors ◽  
Before And After ◽  
Nationally Representative ◽  
Risk Of Cancer

Many adult cancer patients present one or more physical comorbidities. Besides interfering with treatment and prognosis, physical comorbidities could also increase the already heightened psychological risk of cancer patients. To test this possibility, we investigated the relationship between physical comorbidities with depression symptoms in a sample of 2073 adult cancer survivors drawn from the nationally representative National Health and Nutrition Examination Survey (NHANES) (2007–2018) in the U.S. Based on information regarding 16 chronic conditions, the number of comorbidities diagnosed before and after the cancer diagnosis was calculated. The number of comorbidities present at the moment of cancer diagnosis was significantly related to depression risk in recent but not in long-term survivors. Recent survivors who suffered multimorbidity had 3.48 (95% CI 1.26–9.55) times the odds of reporting significant depressive symptoms up to 5 years after the cancer diagnosis. The effect of comorbidities was strongest among survivors of breast cancer. The comorbidities with strongest influence on depression risk were stroke, kidney disease, hypertension, obesity, asthma, and arthritis. Information about comorbidities is usually readily available and could be useful in streamlining depression screening or targeting prevention efforts in cancer patients and survivors. A multidimensional model of the interaction between cancer and other physical comorbidities on mental health is proposed.

scholarly journals Efficacy and Safety of Long-Term Low-Dose Clarithromycin in Patients With Refractory Chronic Sinusitis After Endoscopic Sinus Surgery: A Prospective Clinical Trial

2021 ◽  
pp. 014556132110320
Author(s):  
Han Chen ◽  
Bing Zhou ◽  
Qian Huang ◽  
Cheng Li ◽  
Yubin Wu ◽  
...  
Keyword(s):  
Oral Administration ◽  
Nasal Cavity ◽  
Endoscopic Sinus Surgery ◽  
Low Dose ◽  
Continuous Treatment ◽  
Sinus Surgery ◽  
Efficacy And Safety ◽  
Endoscopic Findings ◽  
Before And After

Objective: To observe the efficacy and safety of postoperative long-term low-dose oral administration of clarithromycin in patients with refractory chronic rhinosinusitis (RCRS), to explore the characteristics of postoperative microbiota in the nasal cavity in patients with RCRS, and to compare the differences and changes in microbiota in the nasal cavity before and after medication. Methods: This was a prospective, self-controlled study. Eighteen patients with RCRS who had persistent symptoms after endoscopic sinus surgery and standard therapy with normal immunoglobulin E and eosinophil level were included. Low dose (250 mg, once daily) clarithromycin was orally administrated for 12 weeks. Symptom severity and endoscopic findings were evaluated before, after 4 weeks, and 12 weeks of treatment, and nasal cavity microbiota was analyzed simultaneously. Results: A total of 18 patients with RCRS were enrolled and 17 patients completed the study. Four weeks after oral administration of clarithromycin, significant improvement was observed in subjective symptoms including nasal congestion, rhinorrhea, postnasal drip, and general discomfort, as well as endoscopic findings including general surgical cavity condition, rhinedema, and rhinorrhea ( P < .05). After continuous treatment to the 12th week, symptoms showed significant improvement compared with baseline, and endoscopic score showed significant improvement compared with both baseline and 4 weeks after treatment. Analysis of middle nasal meatus flora revealed a significant decrease of Streptococcus pneumoniae after 12 weeks of clarithromycin treatment ( P < .05), while the richness, composition, and diversity were similar before and after treatment. Patients enrolled experienced no adverse drug reaction or allergic reaction, nor clinical significant liver function impairment observed. Conclusion: Postoperative low-dose long-term oral administration of clarithromycin in patients with RCRS can improve the clinical symptoms and facilitate the mucosal epithelialization, with good tolerance and safety. The efficacy of clarithromycin in patients with RCRS may be related to its regulatory effect on nasal cavity microbiota.

scholarly journals Long-term complications after stent assist coiling dependent on clopidogrel response

BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kenji Shoda ◽  
Yukiko Enomoto ◽  
Yusuke Egashira ◽  
Takamasa Kinoshita ◽  
Daisuke Mizutani ◽  
...  
Keyword(s):  
Acute Phase ◽  
Platelet Reactivity ◽  
Unruptured Aneurysms ◽  
Hemorrhagic Events ◽  
Before And After ◽  
Verifynow Assay ◽  
Previously Treated ◽  
The Relationship ◽  
Delayed Phase

Abstract Background Dual antiplatelet therapy (DAPT) is necessary for stent assisted coiling. However, long term use of DAPT has a potential risk of hemorrhagic events. We aimed to examine the relationship between clopidogrel reactivity and complications. Methods Patients who underwent stent assisted coiling for unruptured aneurysms or previously treated aneurysms and received periprocedural DAPT in our institution between August 2011 to March 2020 were included. Platelet reactivity for clopidogrel was measured by VerifyNow assay system, and we defined the cut off value of P2Y12 Reaction Units (PRU) at 208 and classified patients as hypo-responders (PRU≧208) or responders (PRU<208). The rates of hemorrhagic and thrombotic events within 30 days (acute phase) and 30 days after the procedure (delayed phase) were compared between the two groups. Furthermore, changes in hemoglobin levels were measured before and after the procedure and at chronic stages (1 to 6 months thereafter). Results From 61 patients included in this study, 36 patients were hypo-responders and 25 patients were responders. Hemorrhagic events occurred 8.0% only in responders in the acute phase (p = 0.16), and 2.78% in hypo-responders and 20.0% in responders in the delayed phase (p = 0.037). Changes in hemoglobin levels before and after the procedure were 1.22 g/dl in hypo-responders and 1.74 g/dl in responders (p = 0.032) while before the procedure and chronic stages they were 0.39 g/dl in hypo-responders and 1.39 g/dl in responders (p <  0.01). Thrombotic events were not significantly different between the two groups. Conclusion Long term use of DAPT after stent assisted coiling is related to hemorrhagic events in the delayed phase. Preventing for hemorrhagic events, the duration of DAPT should be carefully considered in clopidogrel responders.

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