Polyurethane nanocomposite based gas barrier films, membranes and coatings: A review on synthesis, characterization and potential applications

Output performance analyses of solar array on stratospheric airship with thermal effect

Background: The link between body weight status and spinal diseases has been suggested by a number of cross-sectional and cohort studies with a limited range of patient populations. No population-representative samples have been used to examine the link between obesity and spinal diseases. The present study is based on a nationally representative sample drawn from the Medical Expenditure Panel Survey. Methods: Using the cross-sectional sample of the 2014 Medical Expenditure Panel Study, we built four weighted logistic regression analyses of the associations between body weight status and the following four spinal diseases: low back pain, spondylosis, other cervical disorders and intervertebral disc disorder (IDD). Each respondent's body weight status was used as the key independent variable with three categories: normal/underweight, overweight, and obese. We controlled for marital status, gender, age, smoking status, household income, health insurance coverage, educational attainment and the use of health services for other major categories of diseases. Results: A total sample of 23,048 respondents was used in our analysis. Overweight and obese respondents, as compared to normal/underweight respondents, were more likely to develop lower back problems (Overweight: logged odds = 0.218, p < 0.01; Obese: logged odds = 0.395, p < 0.001) and IDD (Overweight: logged odds = 0.441, p < 0.05; Obese: logged odds = 0.528, p < 0.001). The associations between bodyweight status and spondylitis were statistically insignificant (Overweight: logged odds = 0.281, p = 0.442; Obese: logged odds = 0.680, p = 0.104). The associations between body weight status and other cervical disorders (Overweight: logged odds = -0.116, p = 0.304; Obese: logged odds = -0.160, p = 0.865) were statistically insignificant. Conclusions: As the first study using a national sample to study bodyweight and spinal diseases, our paper supports the hypothesis that obesity adds to the burden of low back pain and IDD. Longitudinal and interventional studies are needed to understand the specific mechanisms behind these positive associations.

https://www.mdpi.com/1660-4601/14/2/183/pdf

Associations between Obesity and Spinal Diseases: A Medical Expenditure Panel Study Analysis

Thermal modeling of stratospheric airships

The clinical anatomy of the visual system.

A comprehensive numerical model examining the thermal performance of airships

An in vitro experimental study on the relationship between pulsatile tinnitus and the dehiscence/thinness of sigmoid sinus cortical plate.

Purpose To evaluate retinal damage as the result of craniomaxillofacial trauma and explain its pathogenic mechanism using finite element (FE) simulation. Methods Computed tomography (CT) images of an adult man were obtained to construct a FE skull model. A FE skin model was built to cover the outer surface of the skull model. A previously validated FE right eye model was symmetrically copied to create a FE left eye model, and both eye models were assembled to the skull model. An orbital fat model was developed to fill the space between the eye models and the skull model. Simulations of a ball-shaped object striking the frontal bone, temporal bone, brow, and cheekbones were performed, and the resulting absorption of the impact energy, intraocular pressure (IOP), and strains on the macula and ora serrata were analyzed to evaluate retinal injuries. Results Strain was concentrated in the macular regions (0.18 in average) of both eyes when the frontal bone was struck. The peak strain on the macula of the struck-side eye was higher than that of the other eye (>100%) when the temporal bone was struck, whereas there was little difference ( 0.8 and P = 0.000 in all simulation cases). Conclusions The risk of retinal damage is variable in craniomaxillofacial trauma depending on the struck region, and the damage is highly related to IOP variation caused by indirect blunt eye trauma. Translational relevance This finite element eye model allows us to evaluate and understand the indirect ocular injury mechanisms in craniomaxillofacial trauma for better clinical diagnosis and treatment.

Mechanical evaluation of retinal damage associated with blunt craniomaxillofacial trauma: a simulation analysis

Biomechanical analysis of combining head-down tilt traction with vibration for different grades of degeneration of the lumbar spine

Pulsatile tinnitus (PT) is a common symptom in otology. In some cases, the venous flow in the sigmoid sinus (SS) is the source of PT. It is suggested that the venous sound is propagated into the tympanic cavity through the air pathway of temporal bone air cells (TBAC). The hyperpneumatization of TBAC was hypothesized as a direct pathology of PT through amplifying the venous sound, but there is no quantitative analysis. This study aims to quantify the relationship between the venous sound amplification and the pneumatization grade of TBAC. The acoustic numerical simulation and statistical analysis were performed based on the radiology data of 21 pulsatile tinnitus patients. The TBAC of these patients were classified into hypopneumatization, normal pneumatization and hyperpneumatization grades according to three standards. The in vitro acoustic experiment was done as the validation of simulation. It is indicated that the SS standard is effective for the clinical evaluation of venous sound amplification. The TBAC amplifies the venous sound due to the acoustic resonance at the first mode frequency, regardless of the pneumatization grades. The normal pneumatic TBAC exhibits the highest sound amplification effect on the venous sound amongst the three grades, contributing mostly to PT, but would not induce PT without any other causes.

Yawei Wang

Papers

A comprehensive numerical model examining the thermal performance of airships

An in vitro experimental study on the relationship between pulsatile tinnitus and the dehiscence/thinness of sigmoid sinus cortical plate.

Mechanical evaluation of retinal damage associated with blunt craniomaxillofacial trauma: a simulation analysis

Biomechanical analysis of combining head-down tilt traction with vibration for different grades of degeneration of the lumbar spine

A study on relationship between pulsatile tinnitus and temporal bone pneumatization grade.