For further morphological and physiological research, it is vital to establish precise three-dimensional models of the whole inner ear including the details of the membranous components. With the system of a projector and a high-resolution digital camera, 2 complete serial unstained celloidin sections of fresh human temporal bones were digitized as high-resolution images which were then sorted, calibrated, aligned and segmented using the 3D-Doctor software. Finally, 2 precise three-dimensional models of the inner ear were generated by simple surface rendering. The contours of tiny structures such as the crista ampullaris, the macula utriculi and the macula sacculi could be observed clearly. Our study suggests that it is technically feasible to employ complete serial unstained celloidin sections for precise three-dimensional reconstruction and that this helps reduce errors and laboratory workload. Moreover, the use of a high-resolution digital camera and the autoalignment function of 3D-Doctor further increase the accuracy of the models.

The floating piezoelectric microphone is expected to be used as an implantable middle ear microphone for the totally implantable cochlear implant.

The development of transmucosal drug delivery systems is a practical requirement in oral clinical practice, and controlled sequential delivery of multiple drugs is usually required. On the basis of the previous successful construction of monolayer microneedles (MNs) for transmucosal drug delivery, we designed transmucosal double-layer sequential dissolving MNs using hyaluronic acid methacryloyl (HAMA), hyaluronic acid (HA), and polyvinyl pyrrolidone (PVP). MNs have the advantages of small size, easy operation, good strength, rapid dissolution, and one-time delivery of two drugs. Morphological test results showed that the HAMA-HA-PVP MNs were small and intact in structure. The mechanical strength and mucosal insertion test results indicated the HAMA-HA-PVP MNs had appropriate strength and could penetrate the mucosal cuticle quickly to achieve transmucosal drug delivery. The in vitro and in vivo experiment results of the double-layer fluorescent dyes simulating drug release revealed that MNs had good solubility and achieved stratified release of the model drugs. The results of the in vivo and in vitro biosafety tests also indicated that the HAMA-HA-PVP MNs were biosafe materials. The therapeutic effect of drug-loaded HAMA-HA-PVP MNs in the rat oral mucosal ulcer model demonstrated that these novel HAMA-HA-PVP MNs quickly penetrated the mucosa, dissolved and effectively released the drug, and achieved sequential drug delivery. Compared to monolayer MNs, these HAMA-HA-PVP MNs can be used as double-layer drug reservoirs for controlled release, effectively releasing the drug in the MN stratification by dissolution in the presence of moisture. The need for secondary or multiple injections can be avoided, thus improving patient compliance. This drug delivery system can serve as an efficient, multipermeable, mucosal, and needle-free alternative for biomedical applications.

ObjectivesTo quantitatively analyzing the anatomic variants on temporal computed tomography (CT) in congenital external auditory canal stenosis (EACS), congenital aural atresia (CAA), and normal ear structure.MethodsThrough a retrospective study, we analyzed 142 temporal high-resolution CT studies performed in 71 microtia patients. The following 6 parameters were compared among the three groups: Marx classification, medial canal diameter, vertical facial nerve (VFN) anterior displacement, tegmen mastoideum position, tympanic cavity volume, and malleus-incus joint or malleus-incus complex (MIC) area.ResultsThe results showed that the microtia distributions in the Marx classification in these three groups were significantly different, as 86% (31 of 35) of ears with major microtia (third-degree dysplasia) had an atresia, and in 54.8% (23 of 42) of the minor microtic (first-degree or second-degree) ears, the bony or cartilaginous part of the external auditory canal was stenotic. Measurement data also showed that the potential medial canal diameter of the atresia group was obviously shorter than that of the stenosis group. The VFN anterior displacement and temporomandibular joint backward-shift together lead to medial canal diameters in ears with atresic canals that is smaller than those with stenotic canals. The tegmen mastoideum position was not significantly different between the three groups.ConclusionThe mal-development of the external auditory canal is significantly associated with auricle and middle ear developmental anomalies. Compared with CAA ears, EACS have better development of the auricle, canal, tympanic cavity and MIC and relatively safer surgical operation except for the position of the tegmen mastoideum and the VFN.

No abstract

This study employed traditional and advanced echocardiographic techniques to assess comprehensively age- and sex-related changes in cardiovascular structure and function in wildtype (WT) mice. Forty-five normal adult wildtype mice were apportioned to groups based on age and sex: 2-month (young) male or female, and 24-month (old) male or female (n = 13, 13, 13, and 6, respectively). Each underwent 2-dimensional (2D) imaging echocardiography, Doppler, tissue Doppler imaging echocardiography, and speckle-tracking echocardiography (STE) for comparison of cardiovascular structure and function parameters. Compared to the young mice, the old had significantly higher body weight (BW), and lower diastolic and mean arterial pressure. The left ventricular (LV) end-diastolic and end-systolic volumes, and left ventricular mass, were significantly higher in the old mice. Within each sex, the cardiac diastolic and systolic function parameters were comparable between the young and old. Isovolumetric relaxation time (IVRT)/diastolic time interval (DT) and the maximum drop rate of pressure in LV (− dP/dtmax) were significantly lower in the old mice, while the LV relaxation time constant (Tau) was significantly higher. Spearman’s rank correlation showed a positive association between IVRT/DT and − dp/dtmax (male r = 0.663; female r = 0.639). Among the males, the maximum rise rate of pressure in LV (+ dp/dtmax), and systolic global longitudinal strains and rates (S-GLS, S-GLSR) were significantly different between the young and old. Spearman’s rank correlation showed positive association between S-GLS, S-GLSR and + dp/dtmax (r = 0.709 and r = 0.499). Regarding vascular structure, the ascending aorta systolic and diastolic diameters were significantly higher in the old mice compared with the young. The male mice had progressive, age-related aortic stiffness. Ageing in mice leads to changes in cardiovascular structure and cardiac diastolic function, but systolic function is relatively well preserved in females. Changes in cardiac function and arterial stiffness were more significant in males than females. Traditional ECG is better than STE for evaluating LV diastolic function; STE is better for LV systolic function.

No abstract

TEWI (total equivalent warming impact) index, a comparatively scientific method to evaluate the environmental impact of air-conditioning cold and heat source, is introduced. Taking some engineering in Hunan Province for example, the TEWI analysis was performed on the environmental impact assessment of four air-conditioning cold and heat source plans. Also the first investment and energy consumption were analyzed. The results indicate that: water loop heat pump unit, due to investment recovery period with only 2.9 years and carbon emission reduction up to 22.68%, has significant economy and environmental protection, which is followed by water source heat pump; the screw chilled water units plus gas boiler is poor. Gas direct-fired machine has certain economic advantage, but its environmental performance is general. Among four schemes, the proportion of indirect effects of CO2emissions from fossil fuels used to generate energy to operate the equipment throughout its lifetime are all larger, respectively is 95.1%, 95.2%, 100% and 89.9%. It fully showed the importance of developing clean and renewable energy, reducing energy consumption and increasing performance coefficient of refrigeration and air conditioning device.