Three-Dimensional Finite Element Modeling of Blast Wave Transmission From the External Ear to a Spiral Cochlea.

Blast-induced injuries affect the health of veterans, in which the auditory system is often damaged, and blast-induced auditory damage to the cochlea is difficult to quantify. A recent study modeled blast overpressure (BOP) transmission throughout the ear utilizing a straight, two-chambered cochlea, but the spiral cochlea's response to blast exposure has yet to be investigated. In this study, we utilized a human ear finite element (FE) model with a spiraled, two-chambered cochlea to simulate the response of the anatomical structural cochlea to BOP exposure. The FE model included an ear canal, middle ear, and two and half turns of two-chambered cochlea and simulated a BOP from the ear canal entrance to the spiral cochlea in a transient analysis utilizing fluid-structure interfaces. The model's middle ear was validated with experimental pressure measurements from the outer and middle ear of human temporal bones. The results showed high stapes footplate (SFP) displacements up to 28.5 µm resulting in high intracochlear pressures and basilar membrane (BM) displacements up to 43.2 µm from a BOP input of 30.7 kPa. The cochlea's spiral shape caused asymmetric pressure distributions as high as 4 kPa across the cochlea's width and higher BM transverse motion than that observed in a similar straight cochlea model. The developed spiral cochlea model provides an advancement from the straight cochlea model to increase the understanding of cochlear mechanics during blast and progresses toward a model able to predict potential hearing loss after blast.

[A ten-year follow-up study of a patient with chronic renal failure and metastatic pulmonary calcification after parathyroidectomy and review of the literature].

Objective: To analyze whether parathyroidectomy can prevent the progress of metastatic pulmonary calcification (MPC) in patients with chronic renal failure (CRF). Methods: A male patient with CRF complicated with MPC who underwent parathyroidectomy for secondary hyperparathyroidism and parathyroid adenoma was followed up for 10 years. The changes of MPC and the levels of blood calcium and phosphorus were measured. We searched the relevant literatures in PubMed and Wanfang databases with the key words of "metastatic pulmonary calibration" and "parathyroidectomy". Then, we manually retrieved the references of the literatures. A total of 18 patients (17 patients from 14 publications as well as the present case) were analyzed. By comparing the characteristics of MPC improvement group and MPC progression group, the factors affecting the prognosis of MPC after parathyroidectomy were explored. Results: After parathyroidectomy, the thoracic CT images of the patient gradually worsened from normal to diffuse ground glass opacity of both lungs, which indicated that parathyroidectomy did not prevent the progression of MPC in this patient. Among the 18 MPC patients who underwent parathyroidectomy, 10 patients had improved MPC, three had CRF, and two received peritoneal dialysis or hemodialysis respectively; eight patients had progressed MPC, all of the patients were CRF patients, one patient received peritoneal dialysis, and other patients received hemodialysis. Compared between the two groups, the proportion of CRF patients (P=0.004) and hemodialysis patients (P=0.003) in the progression group were significantly higher than those in the improvement group. Conclusion: Parathyroidectomy cannot prevent the progression of MPC in hemodialysis patients with CRF.

[Treatment strategies and research progress of acute ilio-femoral deep vein thrombosis].

In the past,treatment of acute ilio-femoral deep vein thrombosis (IFDVT) was mainly based on anticoagulation alone,but 30%-50% of patients will develop post-thrombotic syndrome,causing a serious medical burden.Thrombus removal technology such as catheter-directed thrombolysis and percutaneous mechanical thrombectomy can effectively remove blood clots and compensate for the deficiencies of simple anticoagulation,which is expected to improve the prognosis of such disease,but the current evidence is insufficient,and other treatments such as filter implantation and compression therapy are also controversial.This article summarizes the treatment strategies and the latest progress of acute IFDVT,hoping to help the treatment of this type of disease.

Effect of coronavirus disease 2019 (COVID-19) on maternal, perinatal and neonatal outcome: systematic review.

OBJECTIVE: To evaluate the effect of coronavirus disease 2019 (COVID-19) on maternal, perinatal and neonatal outcome by performing a systematic review of available published literature on pregnancies affected by COVID-19. METHODS: We performed a systematic review to evaluate the effect of COVID-19 on pregnancy, perinatal and neonatal outcome. We conducted a comprehensive literature search using PubMed, EMBASE, the Cochrane Library, China National Knowledge Infrastructure Database and Wan Fang Data up to and including 20 April 2020 (studies were identified through PubMed alert after that date). For the search strategy, combinations of the following keywords and medical subject heading (MeSH) terms were used: 'SARS-CoV-2', 'COVID-19', 'coronavirus disease 2019', 'pregnancy', 'gestation', 'maternal', 'mother', 'vertical transmission', 'maternal-fetal transmission', 'intrauterine transmission', 'neonate', 'infant' and 'delivery'. Eligibility criteria included laboratory-confirmed and/or clinically diagnosed COVID-19, patient being pregnant on admission and availability of clinical characteristics, including at least one maternal, perinatal or neonatal outcome. Exclusion criteria were non-peer-reviewed or unpublished reports, unspecified date and location of the study, suspicion of duplicate reporting and unreported maternal or perinatal outcomes. No language restrictions were applied. RESULTS: We identified a high number of relevant case reports and case series, but only 24 studies, including a total of 324 pregnant women with COVID-19, met the eligibility criteria and were included in the systematic review. These comprised nine case series (eight consecutive) and 15 case reports. A total of 20 pregnant patients with laboratory-confirmed COVID-19 were included in the case reports. In the combined data from the eight consecutive case series, including 211 (71.5%) cases of laboratory-confirmed and 84 (28.5%) of clinically diagnosed COVID-19, the maternal age ranged from 20 to 44 years and the gestational age on admission ranged from 5 to 41 weeks. The most common symptoms at presentation were fever, cough, dyspnea/shortness of breath, fatigue and myalgia. The rate of severe pneumonia reported amongst the case series ranged from 0% to 14%, with the majority of the cases requiring admission to the intensive care unit. Almost all cases from the case series had positive computed tomography chest findings. All six and 22 cases that had nucleic-acid testing in vaginal mucus and breast milk samples, respectively, were negative for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Only four cases of spontaneous miscarriage or termination were reported. In the consecutive case series, 219/295 women had delivered at the time of reporting and 78% of them had Cesarean section. The gestational age at delivery ranged from 28 to 41 weeks. Apgar scores at both 1 and 5 min ranged from 7 to 10. Only eight neonates had birth weight < 2500 g and nearly one-third of neonates were transferred to the neonatal intensive care unit. There was one case of neonatal asphyxia and death. In 155 neonates that had nucleic-acid testing in throat swab, all, except three cases, were negative for SARS-CoV-2. There were no cases of maternal death in the eight consecutive case series. Seven maternal deaths, four intrauterine fetal deaths (one with twin pregnancy) and two neonatal deaths (twin pregnancy) were reported in a non-consecutive case series of nine cases with severe COVID-19. In the case reports, two maternal deaths, one neonatal death and two cases of neonatal SARS-CoV-2 infection were reported. CONCLUSIONS: Despite the increasing number of published studies on COVID-19 in pregnancy, there are insufficient good-quality data to draw unbiased conclusions with regard to the severity of the disease or specific complications of COVID-19 in pregnant women, as well as vertical transmission, perinatal and neonatal complications. In order to answer specific questions in relation to the impact of COVID-19 on pregnant women and their fetuses, through meaningful good-quality research, we urge researchers and investigators to present complete outcome data and reference previously published cases in their publications, and to record such reporting when the data of a case are entered into one or several registries. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Efecto de la enfermedad coronavirus 2019 (COVID-19) en el resultado materno, perinatal y neonatal: revisión sistemática OBJETIVO: Evaluar el efecto de la enfermedad coronavirus 2019 (COVID-19) en el resultado materno, perinatal y neonatal por medio de una revisión sistemática de la literatura publicada disponible sobre los embarazos afectados por COVID-19. MÉTODOS: Se realizó una revisión sistemática para evaluar el efecto de COVID-19 en el resultado del embarazo, perinatal y neonatal. Se realizó una búsqueda exhaustiva de literatura utilizando PubMed, EMBASE, la Biblioteca Cochrane, la Base de Datos de la Infraestructura Nacional de Conocimiento de China y Wan Fang Data hasta el 20 de abril de 2020 inclusive (los estudios se identificaron mediante el sistema de alertas de PubMed después de esa fecha). Para la estrategia de búsqueda, se utilizaron combinaciones de las siguientes palabras clave y términos (en inglés) de Medical Subject Headings (MeSH): 'SARS-CoV-2', 'COVID-19', 'enfermedad coronavirus 2019', 'embarazo', 'gestación', 'materno', 'madre', 'transmisión vertical', 'transmisión materno-fetal', 'transmisión intrauterina', 'neonato', 'bebé' y 'parto'. Los criterios de elegibilidad fueron COVID-19 confirmado por laboratorio y/o diagnosticado clínicamente, el hecho de que la paciente estuviera embarazada en el momento del ingreso y la disponibilidad de características clínicas, con al menos un resultado materno, perinatal o neonatal. Los criterios de exclusión fueron los informes no revisados por pares o no publicados, la fecha y el lugar del estudio sin especificar, la sospecha de informes duplicados y los resultados maternos o perinatales no reportados. No se aplicaron restricciones de idioma. RESULTADOS: Se identificó un elevado número de informes de casos y series de casos pertinentes, pero sólo 24 estudios, que incluían un total de 324 mujeres embarazadas con COVID-19, cumplieron los criterios de elegibilidad y se incluyeron en la revisión sistemática. Estos comprendían nueve series de casos (ocho consecutivas) y 15 informes de casos. Los informes de casos se referían a un total de 20 pacientes embarazadas con COVID-19 confirmado por un laboratorio. En los datos combinados de las ocho series de casos consecutivas, que incluían 211 (71,5%) casos de COVID-19 confirmados por laboratorio y 84 (28,5%) casos diagnosticados clínicamente, la edad materna varió entre 20 y 44 años y la edad gestacional en el momento del ingreso fue entre 5 y 41 semanas. Los síntomas más comunes del cuadro clínico inicial fueron fiebre, tos, disnea/dificultad para respirar, fatiga y mialgia. La tasa de neumonía grave reportada en las series de casos varió entre el 0% y el 14%, y la mayoría de los casos requirieron el ingreso en la unidad de cuidados intensivos. Casi todos los casos de la serie de casos tuvieron resultados positivos en la tomografía axial computerizada. Los 6 y 22 casos en que se realizaron pruebas de ácido nucleico en muestras de mucosidad vaginal y leche materna, respectivamente, dieron negativo para el síndrome respiratorio agudo severo coronavirus 2 (SARS-CoV-2). Sólo se notificaron cuatro casos de aborto o interrupción del embarazo. En la serie de casos consecutivos, 219 de 295 mujeres habían dado a luz en el momento de la presentación del informe y el 78% de ellas lo hicieron mediante cesárea. La edad gestacional en el momento del parto varió entre 28 y 41 semanas. Las puntuaciones de Apgar a 1 minuto y a 5 minutos variaron entre 7 y 10. Sólo ocho recién nacidos pesaron al nacer <2500 g y casi un tercio de los recién nacidos fueron transferidos a la unidad de cuidados intensivos para recién nacidos. Hubo un caso de asfixia y muerte neonatal. Excepto tres casos, el resto de los 155 neonatos a los que se les hicieron pruebas de ácido nucleico en un frotis faríngeo, dieron negativo para el SARS-CoV-2. No hubo casos de muerte materna en las ocho series consecutivas de casos. Se reportaron siete muertes maternas, cuatro muertes fetales intrauterinas (una con embarazo de gemelos) y dos muertes de recién nacidos (embarazo de gemelos) en una serie no consecutiva de nueve casos con COVID-19 grave. En los informes de casos se comunicaron dos muertes maternas, una muerte de recién nacido y dos casos de infección de recién nacidos por SARS-CoV-2. CONCLUSIONES: A pesar del creciente número de estudios publicados sobre COVID-19 en embarazos, no hay suficientes datos de buena calidad para sacar conclusiones no sesgadas con respecto a la gravedad de la enfermedad o a las complicaciones específicas de COVID-19 en las mujeres embarazadas, así como a la transmisión vertical y a las complicaciones perinatales y neonatales. A fin de responder a preguntas específicas en relación con los efectos de COVID-19 en mujeres embarazadas y sus fetos, mediante una investigación significativa de buena calidad, se insta a los investigadores y a los encargados de investigaciones a que presenten en sus publicaciones datos completos sobre los resultados y casos de referencia publicados anteriormente, y a que registren esos informes cuando los datos de un caso se introduzcan en uno o varios registros. © 2020 Los autores. Ultrasonido en Obstetricia y Ginecología publicado por John Wiley & Sons Ltd. en nombre de la Sociedad Internacional de Ultrasonido en Obstetricia y Ginecología.

[Risk assessment of exported risk of COVID-19 from Hubei Province].

Objective: To evaluate the exported risk of COVID-19 from Hubei Province and the imported risk in various provinces across China. Methods: Data of reported COVID-19 cases and Baidu Migration Indexin all provinces of the country as of February 14, 2020 were collected. The correlation analysis between cumulative number of reported cases and the migration index from Hubei was performed, and the imported risks from Hubei to different provinces across China were further evaluated. Results: A total of 49 970 confirmed cases were reported nationwide, of which 37 884 were in Hubei Province. The average daily migration index from Hubei to other provinces was 312.09, Wuhan and other cities in Hubei were 117.95 and 194.16, respectively. The cumulative COVID-19 cases of provinces was positively correlated with the migration index derived from Hubei Province, also in Wuhan and other cities in Hubei, with correlation coefficients of 0.84, 0.84, and 0.81. In linear model, population migration from Hubei Province, Wuhan and other cities in Hubei account for 71.2%, 70.1%, and 66.3% of the variation, respectively. The period of high exported risk from Hubei occurred before January 27, of which the risks before January 23 mainly came from Wuhan, and then mainly from other cities in Hubei. Hunan Province, Henan Province and Guangdong Province ranked the top three in terms of cumulative imported risk (the cumulative risk indices were 58.61, 54.75 and 49.62 respectively). Conclusion: The epidemic in each province was mainly caused by the importation of Hubei Province. Taking measures such as restricting the migration of population in Hubei Province and strengthening quarantine measures for immigrants from Hubei Province may greatly reduce the risk of continued spread of the epidemic.

Clinical and genetic features of Chinese patients with lichen and macular primary localized cutaneous amyloidosis.

BACKGROUND: Primary localized cutaneous amyloidosis (PLCA) is a chronic pruritic skin disorder. The genetic basis of familial (f)PLCA involves mutations in the oncostatin M receptor (OSMR) and interleukin-31 receptor A (IL31RA) genes, but the disease pathophysiology is not fully understood. AIM: To investigate the OSMR mutation spectrum in patients with sporadic (s)PLCA/fPLCA, lichen/macular PLCA in mainland China. METHODS: This study was carried out on 64 patients with sPLCA, along with 36 with fPLCA and 10 unaffected individuals collected from 23 unrelated Chinese families. Genomic DNA was extracted from peripheral blood samples. Mutation screening of 17 OSMR exons was performed by Sanger sequencing. RESULTS: PLCA lesions are typically localized to the shins, forearm and back. Sequence analysis of OSMR exons demonstrated that the OSMR missense mutation rate in patients with fPLCA (63.89%) was significantly higher than that in patients with sPLCA (34.38%). The male/female ratio of patients carrying a homozygous OSMR mutation (0.29) was significantly lower than that of patients carrying a heterozygous OSMR mutation (1.08; P < 0.05) and of patients with wildtype OSMR (1.75; P < 0.01). Age of onset of PLCA with OSMR homozygous mutation (median age 20 years) was earlier than that of PLCA with OSMR heterozygous mutation (median age 32 years; P < 0.01) or PLCA with wildtype genotype (median age 32 years; P < 0.01). CONCLUSION: The present data indicate OSMR mutations as not only the main cause of fPLCA, but also the potential source of the pathogenesis of sPLCA, although the exact molecular mechanism remains unknown.

Surface Motion Changes of Tympanic Membrane Damaged by Blast Waves.

Eardrum or tympanic membrane (TM) is a multilayer soft tissue membrane located at the end of the ear canal to receive sound pressure and transport the sound into the middle ear and cochlea. Recent studies reported that the TM microstructure and mechanical properties varied after the ear was exposed to blast overpressure. However, the impact of such biomechanical changes of the TM on its movement for sound transmission has not been investigated. This paper reports the full-field surface motion of the human TM using the scanning laser Doppler vibrometry in human temporal bones under normal and postblast conditions. An increase of the TM displacement after blast exposure was observed in the posterior region of the TM in four temporal bone samples at the frequencies between 3 and 4 kHz. A finite element model of human TM with multilayer microstructure and orthogonal fiber network was created to simulate the TM damaged by blast waves. The consistency between the experimental data and the model-derived TM surface motion suggests that the tissue injuries were resulted from a combination of mechanical property change and regional discontinuity of collagen fibers. This study provides the evidences of surface motion changes of the TM damaged by blast waves and possible fiber damage locations.

Synthesis of Unique Phosphazane Macrocycles via Steric Activation of C-N Bonds.

Herein we describe that oxidation reactions of the dimeric cyclophosphazanes, [{P(µ-NR)}2(µ-NR)]2, R = tBu (1), to produce a series of diagonally dioxidized products P4(µ-N tBu)6E2 [E = O (2), S (3), and Se (4)] and tetraoxidized frameworks. The latter display an unexpected C-N bond activation and cleavage to produce a series of novel phosphazane macrocyclic arrangements containing newly formed N-H bonds. Macromolecules P4(µ-N tBu)4(µ-NH)2O4 (5) and P4(µ-N tBu)3(µ-NH)3E4, E = S (6) and Se (7), dicleaved and tricleaved products, respectively, are rare examples of dimeric macrocycles containing NH bridging groups. Our theoretical and experimental studies illustrate that the extent to which these C-N bonds are cleaved can be controlled by modification of steric parameters in their synthesis, by adjusting either the steric bulk of the substituents in the parent framework or the size of the chalcogen element introduced during the oxidation process. Our findings represent new synthetic pathways for the synthesis of otherwise-elusive macrocycle arrangements within the phosphazane family.

Biomechanical Changes of Tympanic Membrane to Blast Waves.

Eardrum or tympanic membrane (TM) is a multilayer soft tissue membrane located at the end of the ear canal to receive sound pressure and transport the sound into the middle ear and cochlea. Rupture of the TM is one of the most frequent injuries of the ear after blast exposure in military service members. The TM mechanical property changes induced by blast waves also affect progressive hearing loss in veterans. This chapter describes the biomechanical measurements and modeling of blast wave transduction through the ear and the TM mechanical property changes after blast exposure. The human TM rupture thresholds were determined with a relationship to blast wave direction. It is found that the sensitivity of TM stress change with respect to the pressure reaching on TM surface characterizes the mechanical damage of the TM in relation to blast waves. Mechanical properties of the human TM after exposure to blasts were measured using acoustic loading and laser Doppler vibrometry with the inverse problem-solving method. The complex modulus of the TM exposed to blast waves had significant reduction compared to normal tissue. The SEM images of post-blast TM showed obvious microstructural changes from the normal TM which indicate the tissue damage caused by blast exposures. This chapter provides important data on human TM damage and mechanical changes induced by blast overpressure waves.

Measurement of thickness and profile of a transparent material using fluorescent stereo microscopy.

Full-field thickness measurement for a thin transparent film is of interest for biological, medical, electronic, and packaging materials. It is a challenging task when the film is curvy, delicate and its thickness varies with location. We report herein a method to measure the thickness of a transparent (flat or curved) material and its topography using a stereo fluorescent profilometry technique. In this technique, two different types of fluorescent particles are deposited to both sides of the transparent film. Selected fluorescent excitation and emission are used to allow the observation of each one surface of the film at a time to determine the surface profile using stereo-based digital image correlation techniques. After the surface profiles for both surfaces are determined, subtraction of one surface profile from the other provides accurate thickness distribution of the film. Validation experiments were conducted using transparent films with known thickness. As an application, a measurement on a contact lens was conducted. The technique is appropriate for measurement of the full-field thickness of objects at other scales, such as soft transparent or translucent biofilms, with which thickness can hardly be measured accurately with other techniques.

Predictions of middle-ear and passive cochlear mechanics using a finite element model of the pediatric ear.

A finite element (FE) model was developed based on histological sections of a temporal bone of a 4-year-old child to simulate middle-ear and cochlear function in ears with normal hearing and otitis media. This pediatric model of the normal ear, consisting of an ear canal, middle ear, and spiral cochlea, was first validated with published energy absorbance (EA) measurements in young children with normal ears. The model was used to simulate EA in an ear with middle-ear effusion, whose results were compared to clinical EA measurements. The spiral cochlea component of the model was constructed under the assumption that the mechanics were passive. The FE model predicted middle-ear transfer functions between the ear canal and cochlea. Effects of ear structure and mechanical properties of soft tissues were compared in model predictions for the pediatric and adult ears. EA responses are predicted to differ between adult and pediatric ears due to differences in the stiffness and damping of soft tissues within the ear, and any residual geometrical differences between the adult ear and pediatric ear at age 4 years. The results have significance for predicting effects of otitis media in children.

Synthesis and Hydrolytic Studies on the Air-Stable [(4-CN-PhO)(E)P(µ-N(t)Bu)]2 (E = O, S, and Se) Cyclodiphosphazanes.

Reaction of 4-CN-PhOH with [ClP(µ-N(t)Bu)]2 (1) (2:1 ratio) in the presence of Et3N produced the functionalized cyclodiphosph(III/III)azane [(4-CN-PhO)P(µ-N(t)Bu)]2 (2). Oxidation of 2 produced cyclodiphosph(V/V)azanes [(4-CN-PhO)(E)P(µ-N(t)Bu)]2 [E = O (3), S (4), and Se (5)]. This is the first example of a series of cyclodiphosph(V/V)azane derivatives obtained from a single cyclophosph(III/III)azane precursor where all the accessible chalcogen oxidized products are air-stable over prolonged periods of time.

Dynamic Properties of Tympanic Membrane in a Chinchilla Otitis Media Model Measured With Acoustic Loading.

Otitis media is the most common infectious disease in young children, which results in changes in the thickness and mechanical properties of the tympanic membrane (TM) and induces hearing loss. However, there are no published data for the dynamic properties of the TM in otitis media ears, and it is unclear how the mechanical property changes are related to TM thickness variation. This paper reports a study of the measurement of the dynamic properties of the TM in a chinchilla acute otitis media (AOM) model using acoustic loading and laser Doppler vibrometry (LDV). AOM was created through transbullar injection of Haemophilus influenzae into the middle ear, and AOM samples were prepared 4 days after inoculation. Vibration of the TM specimen induced by acoustic loading was measured via LDV over a frequency range of 0.1-8 kHz. The experiment was then simulated in a finite element (FE) model, and the inverse-problem solving method was used to determine the complex modulus in the frequency domain. Results from 12 ears (six control and six AOM) show that the storage modulus of the TM from AOM ears was on average 53% higher than that of control ears, while the loss factor was 17.3% higher in control ears than in AOM ears at low-frequency (f < 1 kHz). At high-frequency (e.g., 8000 Hz), there was a mean 40% increase in storage modulus of the TM from AOM compared to control samples. At peak frequency (e.g., 3 kHz), there was a 19.5% increase in loss factor in control samples compared to AOM samples. These findings quantify the changes induced by AOM in the chinchilla TM, namely, a significant increase in both the storage and loss moduli.

Dynamic properties of human stapedial annular ligament measured with frequency-temperature superposition.

Stapedial annular ligament (SAL) is located at the end of human ear ossicular chain and provides a sealed but mobile boundary between the stapes footplate and cochlear fluid. Mechanical properties of the SAL directly affect the acoustic-mechanical transmission of the middle ear and the changes of SAL mechanical properties in diseases (e.g., otosclerosis) may cause severe conductive hearing loss. However, the mechanical properties of SAL have only been reported once in the literature, which were obtained under quasi-static condition (Gan, R. Z., Yang, F., Zhang, X., and Nakmali, D., 2011, "Mechanical Properties of Stapedial Annular Ligament," Med. Eng. Phys., 33, pp. 330-339). Recently, the dynamic properties of human SAL were measured in our lab using dynamic-mechanical analyzer (DMA). The test was conducted at the frequency range from 1 to 40 Hz at three different temperatures: 5 °C, 25 °C, and 37 °C. The frequency-temperature superposition (FTS) principle was applied to extend the testing frequency range to a much higher level. The generalized Maxwell model was employed to describe the constitutive relation of the SAL. The storage shear modulus G' and the loss shear modulus G" were obtained from seven specimens. The mean storage shear modulus was 31.7 kPa at 1 Hz and 61.9 kPa at 3760 Hz. The mean loss shear modulus was 1.1 kPa at 1 Hz and 6.5 kPa at 3760 Hz. The dynamic properties of human SAL obtained in this study provide a better description of the damping behavior of soft tissues than the classic Rayleigh type damping, which was widely used in the published ear models. The data reported in this study contribute to ear biomechanics and will improve the accuracy of finite element (FE) model of the human ear.

Molecular cloning and characterization of a novel chicken gene named grni.

The full-length cDNA sequence of a novel expressed sequence tag (GenBank accession No. HQ184338) that was differentially expressed during Newcastle disease virus (NDV) infection in chickens was cloned from the chicken spleen by a rapid amplification of cDNA ends assay. This gene was further analyzed using bioinformatic methods and named grni. The full-length cDNA sequence was 1698 bp without introns, locating between 104,691,934 and 104,693,618 in galGal4 on chromosome 2. The open reading frame (ORF) contained 261 bp and encoded a deduced protein of 86 amino acid residues. Furthermore, the encoded protein contained two transmembrane regions without signal peptides, indicating that this protein is located in the mitochondrial membrane. Moreover, its homologous protein was not identified. Real-time polymerase chain reaction was used to detect the dynamic mRNA expression of this gene in the spleen, thymus, bursa of Fabricius, and trachea of NDV-infected chickens. Results suggested that the gene was involved in the transcriptional response of chicken to NDV infection. To obtain a fusion protein and prepare rabbit anti-serum, the predicted ORF of this gene was expressed in Escherichia coli. The expression of this gene at the protein level was further confirmed in the spleen, thymus, and bursa of Fabricius of NDV-infected chickens using Western blot analysis. In conclusion, a novel protein-coding gene named grni was successfully cloned and identified in chickens. Furthermore, this gene was found to be involved in the response of chickens to NDV infection.

3D finite element modeling of earplug-induced occlusion effect in the human ear.

Poor utilization of earplugs among military personnel may be due to discomfort caused by the occlusion effect (OE). The OE occurs when an earplug occludes the ear canal, thereby changing bone conduction (BC) hearing and amplifying physiological noises from the wearer. There is a need to understand and reduce the OE in the human ear. A 3D finite element model of the human ear including a 3-chambered spiral cochlea was employed to simulate the OE caused by foam and aerogel earplugs. 90 dB sound pressure was applied at the ear canal entrance and BC sound was applied as vibration of the canal bony wall. The model reported the ear canal pressure and the displacements of the stapes footplate and cochlear basilar membrane with and without earplugs. Without BC stimulation, the foam earplug showed a greater pressure attenuation than the aerogel earplug. However, the foam earplug results were more affected by BC stimulation, with a maximum sound pressure increase of 34 dB, compared to the 21.0 dB increase with the aerogel earplug. The aerogel earplug's lower OE demonstrates its promise as an earplug material. Future work with this model will examine BC sound transmission in the cochlea.

KL-6 regulated the expression of HGF, collagen and myofibroblast differentiation.

OBJECTIVES: KL-6 is a pulmonary epithelial-derived mucin which is secreted mainly by type II alveolar epithelial cells. The level of KL-6 in serum is closely correlated to the clinical activity of various interstitial lung diseases (ILD) and acts as a prognostic factor for ILD patients. Previous studies have showed that KL-6 promoted chemotaxis, proliferation and inhibited the apoptosis of human lung fibroblasts. However, the underlying mechanism remains unknown. In this study, we investigated the function of KL-6 on the expression of hepatocyte growth factor (HGF), transforming growth factor-ß1 (TGF-ß1), collagen and α-smooth muscle actin(α-SMA) in human embryonic lung fibroblasts cell line MRC-5. METHODS: Human embryonic lung fibroblasts were cultured in Eagle's minimum essential medium. The cells plated in 6-well plates was cultured in serum-free medium at 37°C in 5% CO2 and challenged with recombinant KL-6 at a final concentration of 0, 10, 20, 40 ng/mL. Five micrograms of total RNA template were transcripted to cDNA by using AMV (Avian Myeloblastosis Virus) reverse transcriptase and random 9 mers as the first-strand primer. Synthesized cDNA was used in PCR experiments. The expression of TGF-ß1 and HGF in cell culture supernatants was measured using ELISA kit. Cells incubated with KL-6 for 72h were collected for flow-cytometry analysis. The analysis was done using a Beckman counter device. RESULTS: It was found that KL-6 up-regulated the expression of collagen type I and III in a dose-dependent manner. However, the addition of KL-6 significantly inhibited the production of HGF. As regard to the biological function, KL-6 induced myofibroblast differentiation confirmed by the elevated expression of a-SMA. CONCLUSIONS: KL-6 is one of the key molecules involved in epithelial-mesenchymal interactions and might contribute to the fibrosis in ILD.

Real-time measurement of stapes motion and intracochlear pressure during blast exposure.

Blast-induced auditory injury is primarily caused by exposure to an overwhelming amount of energy transmitted into the external auditory canal, the middle ear, and then the cochlea. Quantification of this energy requires real-time measurement of stapes footplate (SFP) motion and intracochlear pressure in the scala vestibuli (Psv). To date, SFP and Psv have not been measured simultaneously during blast exposure, but a dual-laser experimental approach for detecting the movement of the SFP was reported by Jiang et al. (2021). In this study, we have incorporated the measurement of Psv with SFP motion and developed a novel approach to quantitatively measure the energy flux entering the cochlea during blast exposure. Five fresh human cadaveric temporal bones (TBs) were used in this study. A mastoidectomy and facial recess approach were performed to identify the SFP, followed by a cochleostomy into the scala vestibuli (SV). The TB was mounted to the "head block", a fixture to simulate a real human skull, with two pressure sensors - one inserted into the SV (Psv) and another in the ear canal near the tympanic membrane (P1). The TB was exposed to the blast overpressure (P0) around 4 psi or 28 kPa. Two laser Doppler vibrometers (LDVs) were used to measure the movements of the SFP and TB (as a reference). The LDVs, P1, and Psv signals were triggered by P0 and recorded simultaneously. The results include peak values for Psv of 100.8 ± 51.6 kPa (mean ± SD) and for SFP displacement of 72.6 ± 56.4 µm, which are consistent with published experimental results and finite element modeling data. Most of the P0 input energy flux into the cochlea occurred within 2 ms and resulted in 10-70 µJ total energy entering the cochlea. Although the middle ear pressure gain was close to that measured under acoustic stimulus conditions, the nonlinear behavior of the middle ear was observed from the elevated cochlear input impedance. For the first time, SFP movement and intracochlear pressure Psv have been successfully measured simultaneously during blast exposure. This study provides a new methodology and experimental data for determining the energy flux entering the cochlea during a blast, which serves as an injury index for quantifying blast-induced auditory damage.