nPendred syndrome （PS） is characterized by autosomal recessive inheritance of goiter associated with a defect of iodide organification, hearing loss, enlargement of the vestibular aqueduct （EVA）, and mutations of ...nPendred syndrome （PS） is characterized by autosomal recessive inheritance of goiter associated with a defect of iodide organification, hearing loss, enlargement of the vestibular aqueduct （EVA）, and mutations of the SLC26A4 gene. However, not all EVA patients have PS or SLC26A4 mutations. Two mutant alleles of SLC26A4 are detected in 1/4 of North American or European EVA populations, one mutant allele is detected in another 1/4 of patient populations, and no mutations are de-tected in the other 1/2. The presence of two mutant al-leles of SLC26A4 is associated with abnormal iodide or-ganification, increased thyroid gland volume, increased severity of hearing loss, and bilateral EVA. The pres-ence of a single mutant allele of SLC26A4 is associated with normal iodide organification, normal thyroid gland volume, less severe hearing loss and either bilateral or unilateral EVA. When other underlying correlations are accounted for, the presence of a cochlear malformation or the size of EVA does not have an effect on hearing thresholds. This is consistent with observations of an Slc26a4 mutant mouse model of EVA in which hearing loss is independent of endolymphatic hydrops or in-ner ear malformations. Segregation analyses of EVA in families suggest that the patients carrying one mutant allele of SLC26A4 have a second, undetected mutant allele of SLC26A4, and the probability of a sibling hav-ing EVA is consistent with its segregation as an autoso-mal recessive trait. Patients without any mutations are an etiologically heterogeneous group in which siblings have a lower probability of having EVA. SLC26A4 muta-tion testing can provide prognostic information to guide clinical surveillance and management, as well as the probability of EVA affecting a sibling.展开更多
Introduction: Hidden hearing loss (HHL) is a type of auditory disorder that affects the auditory neural processing and hearing sensitivity in subjects with normal hearing thresholds. Unlike central auditory processing...Introduction: Hidden hearing loss (HHL) is a type of auditory disorder that affects the auditory neural processing and hearing sensitivity in subjects with normal hearing thresholds. Unlike central auditory processing disorders, HHL happens when the cochlea (the peripheral auditory organ) is affected. There are several known risk factors to HHL which includes noise exposure, ototoxic drugs, and peripheral neuropathies, and age. Recent studies have shed light on this type of hearing loss, its etiology, prevalence, and how it can affect the auditory acuity in humans. Methods: This paper covers the current research regarding HHL, its causes, the different mechanisms involved in this disorder, and the diagnosis and potential treatments related to it. We will delve deeply into different researches concerning HHL. 4 articles from 285 were selected focusing on normal hearing individuals with bad speech intelligibility were discussed in this paper. In addition, articles discussing the effects of noise exposure on hearing impaired individuals were not considered as this study solely aims to focus on normal hearing sensitivity individuals with HHL, resulting in 4 articles from 285. Results: Numerous literatures over the decades have suggested that HHL is due to the degeneration of cochlear ribbon synapses, or hair cells synapses without hair cell damage. Their association with HHL was noted several times through this study, whether we were studying the effect of noise exposure, of age, or of ototoxicity. In all cases, no significant hair cell damage was observed, and normal thresholds were recovered. However, a decline in the amplitude of Auditory Brainstem Response (ABR) peak I from auditory nerve (AN) responses in noise exposed subjects and a decline in compound action potential (CAP) was measured when certain drugs were applied to the round window of Guinea pigs. Conclusion: Most studies, have proven that cochlear synaptophysin is the major contributor to noise induced, age, and ototoxic related HHL. There are several audiometric tests that were used to help identify HHL including Puretone audiometry in background noise, ABR, CAP, Distortion Product Otoacoustic Emission (DPOAE).展开更多
The weight loss of cement slurry is the main cause of early annular air channeling and accurate experimental evaluation of the law of loss change is the key to achieve compression stability and prevent this undesired ...The weight loss of cement slurry is the main cause of early annular air channeling and accurate experimental evaluation of the law of loss change is the key to achieve compression stability and prevent this undesired phenomenon.Typically,tests on the pressure loss of cement slurry are carried out for temperature smaller than 120°C,and this condition cannot simulate effectively the situation occurring in high temperature wells.For this reason,in this study a series of experimental tests have been conducted considering a larger range of temperatures,different retarders and fluid loss additives.The results show that with an increase in the temperature,the weight loss curve of cement slurry changes from a“two-stage”to a“three-stage”behavior,and the risk of channeling increases accordingly.On increasing the amount of retarder and fluid loss additive,the transition time of cement slurry displays a non-monotonic behavior(it decreases first and then increases).It is found that the optimized retarder and fluid loss additive dosage are 0.2%and 2.5%,respectively.展开更多
基金Supported by NIH intramural research funds Z01-DC-000039,Z01-DC-000060 and Z01-DC-000064,NIH grants R01-DK43495 and P30-DK34854Kansas State University CVM-SMILE and the Kansas City Area Life Science Institute
文摘nPendred syndrome （PS） is characterized by autosomal recessive inheritance of goiter associated with a defect of iodide organification, hearing loss, enlargement of the vestibular aqueduct （EVA）, and mutations of the SLC26A4 gene. However, not all EVA patients have PS or SLC26A4 mutations. Two mutant alleles of SLC26A4 are detected in 1/4 of North American or European EVA populations, one mutant allele is detected in another 1/4 of patient populations, and no mutations are de-tected in the other 1/2. The presence of two mutant al-leles of SLC26A4 is associated with abnormal iodide or-ganification, increased thyroid gland volume, increased severity of hearing loss, and bilateral EVA. The pres-ence of a single mutant allele of SLC26A4 is associated with normal iodide organification, normal thyroid gland volume, less severe hearing loss and either bilateral or unilateral EVA. When other underlying correlations are accounted for, the presence of a cochlear malformation or the size of EVA does not have an effect on hearing thresholds. This is consistent with observations of an Slc26a4 mutant mouse model of EVA in which hearing loss is independent of endolymphatic hydrops or in-ner ear malformations. Segregation analyses of EVA in families suggest that the patients carrying one mutant allele of SLC26A4 have a second, undetected mutant allele of SLC26A4, and the probability of a sibling hav-ing EVA is consistent with its segregation as an autoso-mal recessive trait. Patients without any mutations are an etiologically heterogeneous group in which siblings have a lower probability of having EVA. SLC26A4 muta-tion testing can provide prognostic information to guide clinical surveillance and management, as well as the probability of EVA affecting a sibling.
文摘Introduction: Hidden hearing loss (HHL) is a type of auditory disorder that affects the auditory neural processing and hearing sensitivity in subjects with normal hearing thresholds. Unlike central auditory processing disorders, HHL happens when the cochlea (the peripheral auditory organ) is affected. There are several known risk factors to HHL which includes noise exposure, ototoxic drugs, and peripheral neuropathies, and age. Recent studies have shed light on this type of hearing loss, its etiology, prevalence, and how it can affect the auditory acuity in humans. Methods: This paper covers the current research regarding HHL, its causes, the different mechanisms involved in this disorder, and the diagnosis and potential treatments related to it. We will delve deeply into different researches concerning HHL. 4 articles from 285 were selected focusing on normal hearing individuals with bad speech intelligibility were discussed in this paper. In addition, articles discussing the effects of noise exposure on hearing impaired individuals were not considered as this study solely aims to focus on normal hearing sensitivity individuals with HHL, resulting in 4 articles from 285. Results: Numerous literatures over the decades have suggested that HHL is due to the degeneration of cochlear ribbon synapses, or hair cells synapses without hair cell damage. Their association with HHL was noted several times through this study, whether we were studying the effect of noise exposure, of age, or of ototoxicity. In all cases, no significant hair cell damage was observed, and normal thresholds were recovered. However, a decline in the amplitude of Auditory Brainstem Response (ABR) peak I from auditory nerve (AN) responses in noise exposed subjects and a decline in compound action potential (CAP) was measured when certain drugs were applied to the round window of Guinea pigs. Conclusion: Most studies, have proven that cochlear synaptophysin is the major contributor to noise induced, age, and ototoxic related HHL. There are several audiometric tests that were used to help identify HHL including Puretone audiometry in background noise, ABR, CAP, Distortion Product Otoacoustic Emission (DPOAE).
基金The authors gratefully acknowledge the research project from“Research and test on optimization of calculation model for cementing engineering of high temperature and high pressure wells”(Grant No.CQCJ-2020-06).
文摘The weight loss of cement slurry is the main cause of early annular air channeling and accurate experimental evaluation of the law of loss change is the key to achieve compression stability and prevent this undesired phenomenon.Typically,tests on the pressure loss of cement slurry are carried out for temperature smaller than 120°C,and this condition cannot simulate effectively the situation occurring in high temperature wells.For this reason,in this study a series of experimental tests have been conducted considering a larger range of temperatures,different retarders and fluid loss additives.The results show that with an increase in the temperature,the weight loss curve of cement slurry changes from a“two-stage”to a“three-stage”behavior,and the risk of channeling increases accordingly.On increasing the amount of retarder and fluid loss additive,the transition time of cement slurry displays a non-monotonic behavior(it decreases first and then increases).It is found that the optimized retarder and fluid loss additive dosage are 0.2%and 2.5%,respectively.
