| 1. |
- Guo, Hua, et al.
(författare)
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Quantitative phase analyses of biomedical pyrophosphate-bearing monetite and brushite cements by solid-state NMR and powder XRD
- 2020
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Ingår i: Ceramics International. - : Elsevier BV. - 0272-8842 .- 1873-3956. ; 46:8, s. 11000-11012
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Tidskriftsartikel (refereegranskat)abstract
- We present a comprehensive composition analysis of calcium phosphate cements (CPCs) incorporating increasing amounts of bioactive pyrophosphate species (up to 17 wt% P2O7). These cements comprise primarily poorly ordered monetite (CaHPO4) or brushite (CaHPO4 center dot 2H(2)O) and are investigated for enhanced osteoinductive bone/tooth implants. The specimens were characterized by magic-angle spinning (MAS) P-31 and H-1 nuclear magnetic resonance (NMR) spectroscopy along with powder X-ray diffraction (PXRD). P-31 MAS NMR was employed to quantify the major monetite/brushite constituents, the crystalline and amorphous pyrophosphates, as well as various minor orthophosphate by-products. The NMR-derived contents of the crystalline phases accorded well with those from Rietveld analyses of the corresponding PXRD data. The amounts of crystalline and amorphous pyrophosphate depended on the precise cement precursor mixture and preparation conditions, which together with their distinct structural roles may enable the design of cements with a tunable P2O74 - release into aqueous solutions.
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| 2. |
- Hua, Håkan, et al.
(författare)
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Cognitive skills and the effect of noise on perceived effort in employees with aided hearing impairment and normal hearing
- 2014
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Ingår i: Noise & Health. - Mumbai India : Medknow Publications. - 1463-1741 .- 1998-4030. ; 16:69, s. 79-88
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the following study was to examine the relationship between working memory capacity (WMC), executive functions (EFs) and perceived effort (PE) after completing a work-related task in quiet and in noise in employees with aided hearing impairment (HI) and normal hearing. The study sample consisted of 20 hearing-impaired and 20 normally hearing participants. Measures of hearing ability, WMC and EFs were tested prior to performing a work-related task in quiet and in simulated traffic noise. PE of the work-related task was also measured. Analysis of variance was used to analyze within-and between-group differences in cognitive skills, performance on the work-related task and PE. The presence of noise yielded a significantly higher PE for both groups. However, no significant group differences were observed in WMC, EFs, PE and performance in the work-related task. Interestingly, significant negative correlations were only found between PE in the noise condition and the ability to update information for both groups. In summary, noise generates a significantly higher PE and brings explicit processing capacity into play, irrespective of hearing. This suggest that increased PE involves other factors such as type of task that is to be performed, performance in the cognitive skill required solving the task at hand and whether noise is present. We therefore suggest that special consideration in hearing care should be made to the individual's prerequisites on these factors in the labor market.
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| 3. |
- Hua, Håkan, et al.
(författare)
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Conceptions of working life among employees with mild-moderate aided hearing impairment : A phenomenographic study
- 2015
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Ingår i: International Journal of Audiology. - : Taylor & Francis. - 1499-2027 .- 1708-8186. ; 54:11, s. 874-880
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The aim was to explore the conceptions of working life among employees with mild-moderate aided hearing impairment (HI).Design: This study has a descriptive design, in which data was collected by means of semi-structured interviews. All interviews were audio-recorded and transcribed verbatim. The text was analysed in accordance with the phenomenographic approach.Study sample: Fifteen participants with mild-moderate aided HI were recruited to the current study.Results: The analysis of the interviews resulted in four main categories describing the participants’ conceptions of working life: (1) diffiiculties in daily work, (2) communication strategies, (3) facilitating factors in work environment, and (4) impact on daily life. The four identified descriptive categories show that the effects of HI on the lives of working adults generate far-reaching psychosocial consequences for the individual.Conclusions: This study demonstrates that difficulties and impact of having a HI interact with strategies used by the individual and contextual facilitators made in the work environment. We argue that there is a need for extensive services in aural rehabilitation for this population. This includes identifying the need of assistive listening devices, teaching the individual with HI about communication strategies and informing stakeholders about the consequence of having a HI.
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| 4. |
- Hua, Håkan
(författare)
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Employees with Aided Hearing Impairment : An Interdisciplinary Perspective
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In Sweden 13% of the general adult population (16-84 years), with or without hearing aids (HAs), report that they have difficulties following a conversation when more than two people are involved. This means that more than one million people in Sweden (9 500 000 inhabitants in total) report subjective hearing difficulties. Observations further indicate that that people with hearing impairment (HI) have an unfavorable position in the labor market. Individuals with HI report poorer health more frequently and estimate their own health to be worse than their normally-hearing peers. Increased unemployment, early health-related retirement and sick leaves are also more common for people with hearing loss compared to the population at large.The focus of the present thesis is employees with mild-moderate aided HI in the labor market. The research project had three general aims: 1) to develop knowledge about how HI interacts with cognitive abilities, and different types of work-related sound environments and workrelated tasks, 2) develop tests and assessment methods that allow for the analysis and assessment of perceived problems in clinical settings and 3) to develop knowledge that enables the possibility to provide recommendations of room acoustics and work-related tasks for employees with HI. Four studies were carried out. The studies presented in papers I-III are quantitative laboratory studies focusing on health related quality of life, cognition and effort and disturbance perceived in different types of occupational noise (daycare, office and traffic). Paper IV is a qualitative interview study aiming at exploring the conceptions of working life among employees with mild-moderate aided HI.The results from papers I-IV clearly demonstrate that noise has negative effects on employees with mild-moderate aided HI. In addition to generating significantly greater effort and disturbance, it is further reported from the participants that noise at work in combination with a HI has an impact on daily life. This includes a sense of exposure during work hours, physical and mental fatigue after work, and withdrawal from social situations in the work environment and leisure activities. None of the participants with HI performed significantly worse on the visual working tasks employed in this project compared to their normallyhearing peers. This thesis shows that employees with HI objectively perform the employed working tasks at a level similar to a well-matched normally-hearing control group. Instead, the findings of this thesis indicates that working in a noisy environment with a HI occurs at the expense of this group reporting significantly worse results on subjective measurements, including greater effort and disturbance, and lower physical health status. Interviews with these participants further confirm that these effects are indeed mostly due to noise at the workplace which could have a negative impact both physically, mentally and socially during and after work hours.The main findings of this thesis demonstrate that there is a need for extensive services for employees with HI even after a HA fitting. This thesis therefore emphasizes the importance of identifying the need for assistive listening devices, examining the room acoustics of the individual’s work setting and providing the workplace with information about the consequences of having a HI in order to facilitate communication at work. The latter is especially important as colleagues showing support and employers making adjustments at the workplace (technically or acoustically) are facilitating factors that would benefit both employees with HI and those with normal hearing. Additional research should focus on including and comparing other types of cognitive tests, work-related noises and working tasks. More research is also needed to unravel the complex area of research between factors such as cognitive processes, hearing and effort.
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| 5. |
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| 6. |
- Hua, Håkan, et al.
(författare)
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Hörselskadade i arbetslivet
- 2012
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Ingår i: Audionomtidningen. - Mölndal : Svenska audionomföreningen. - 1403-1272. ; :2, s. 7-
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 7. |
- Hua, Håkan, et al.
(författare)
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Ny metod för att analysera bullerpåverkan
- 2012
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Ingår i: Buller i arbetslivet. - Stockholm : afa Försäkring. ; , s. 27-29
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Bokkapitel (populärvet., debatt m.m.)abstract
- Hur ser samspelet ut mellan en individs hörförmåga, typ av arbetsuppgift, arbetsrelaterade ljudmiljöoch kognitiva förmåga? Det ville Linköpingsforskarna Björn Lyxell och Håkan Hua ta redapå i sin studie. Med sin breda approach utvecklade de en helt ny metod för att analysera kopplingenmellan arbete och buller.
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| 8. |
- Hua, Håkan, et al.
(författare)
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Quality of life and self-perceived hearing handicap in employees with mild-moderate hearing impairment
- 2013
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Konferensbidrag (refereegranskat)abstract
- Objectives: The aims were to compare health related quality of life (HRQOL) between two groups of employees with normal hearing and hearing impairment (HI) and the results were compared to a normative population. The second aim was to examine self-reported hearing handicap in employees with HI.Design: Data collection occurred in two separate sessions. A validated Swedish version of the Short form-36 (SF-36) was employed to determine HRQOL and The Hearing Handicap Inventory for Adults (HHIA) was used to measure self-perceived hearing handicap.Study Sample: The study sample consisted of hearing-impaired (n = 20) and normally hearing (n = 20) participants. The normative sample comprised of 597 matched respondents.Results: Hearing-impaired employees do not report significantly different HRQOL in comparison with a normative population, nor do they report significantly different HRQOL than their normally hearing peers except in physical functioning (p = 0.04). Results from the HHIA showed mild self-perceived hearing handicap.Conclusions: Employees with mild-moderate HI report good HRQOL and mild self-perceived hearing handicap. However, physical health can be affected even at a mild-moderate HI. This study supports previous literature that HA use, having a job and severity of HI may play a vital role for this group’s well-being.
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| 9. |
- Hua, Håkan, et al.
(författare)
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The impact of different background noises : effects on cognitive performance and perceived disturbance in employees with aided hearing impairment and normal hearing
- 2014
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Ingår i: Journal of the American Academy of Audiology. - : American Academy of Audiology. - 1050-0545 .- 2157-3107. ; 25:9, s. 859-868
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Tidskriftsartikel (refereegranskat)abstract
- Background: Health care professionals frequently meet employees with hearing impairment (HI) who experience difficulties at work. There are indications that the majority of these difficulties might be related to the presence of background noise. Moreover, research has also shown that high-level noise has a more detrimental effect on cognitive performance and self-rated disturbance in individuals with HI than low-level noise.Purpose: The purpose of this study was to examine the impact of different types of background noise on cognitive performance and perceived disturbance (PD) in employees with aided HI and normal hearing.Research Design: A mixed factorial design was conducted to examine the effect of noise in four experimental conditions.Study Sample: A total of 40 participants (21 men and 19 women) were recruited to take part in the study. The study sample consisted of employees with HI (n = 20) and normal hearing (n = 20). The group with HI had a mild-moderate sensorineural HI, and they were all frequent hearing-aid users.Intervention: The current study was conducted by using four general work-related tasks (mental arithmetic, orthographic decoding, phonological decoding, and serial recall) in four different background conditions: (1) quiet, (2) office noise at 56 dBA, (3) daycare noise at 73.5 dBA, and (4) traffic noise at 72.5 dBA. Reaction time and the proportion of correct answers in the working tasks were used as outcome measures of cognitive performance. The Borg CR-10 scale was used to assess PD.Data Collection and Analysis: Data collection occurred on two separate sessions, completed within 4 wk of each other. All tasks and experimental conditions were used in a counterbalanced order. Two-way analysis of variance with repeated measures was performed to analyze the results. To examine interaction effects, pairwise t-tests were used. Pearson correlation coefficients between reaction time and proportion of correct answers, and cognitive performance and PD were also calculated to examine the possible correlation between the different variables.Results: No significant between-group or within-group differences in cognitive performance were observed across the four background conditions. Ratings of PD showed that both groups rated PD according to noise level, where higher noise level generated a higher PD. The present findings also demonstrated that the group with HI was more disturbed by higher than lower levels of noise (i.e., traffic and daycare setting compared with office setting). This pattern was observed consistently throughout four working tasks where the group with HI reported a significantly greater PD in the daycare and traffic settings compared with office noise.Conclusions: The present results demonstrate that background noise does not impair cognitive performance in nonauditory tasks in employees with HI and normal hearing, but that PD is affected to a greater extent in employees with HI during higher levels of background noise exposure. In addition, this study also supports previous studies regarding the detrimental effects that high-level noise has on employees with HI. Therefore, we emphasize the need of both self-rated and cognitive measurements in hearing care and occupational health services for both employees with normal hearing and HI.
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| 10. |
- Håkan, Hua, 1986-, et al.
(författare)
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Cochlear Implant Combined with a Linear Frequency Transposing Hearing Aid
- 2012
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Ingår i: Journal of the American Academy of Audiology. - : American Academy of Audiology. - 1050-0545 .- 2157-3107. ; 23:9, s. 722-732
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Tidskriftsartikel (refereegranskat)abstract
- Background: Adults with cochlear implants (CIs) are usually implanted unilaterally. To preserve binaural advantages, a noninvasive method involves maintaining the hearing aid (HA) on the contralateral ear; the choice of HA for this purpose is therefore crucial. In recent years, the use of frequency transposition has gained a renewed interest in clinical practice. This type of processing records information from the high-frequency region and conveys it to a low-frequency region where there is still some residual hearing. Purpose: To conduct an investigation and examine whether adults with unilateral CI derive benefits from a HA utilizing linear frequency transposition (LFT) on the contralateral ear. Research Design: A two-period, single-blind, repeated-measures crossover design was conducted to examine the combination of LFT in conjunction with a CI. Speech recognition tests were performed in quiet and in noise with LFT either activated or deactivated. The Speech, Spatial and Qualities of Hearing Questionnaire (SSQ) was used to measure subjective benefit. Study Sample: The participants were nine frequent bimodal users, five males and four females, with a moderate to profound high-frequency sensorineural hearing loss in the nonimplanted ear. Intervention: The current study was conducted using the Widex Mind440 power (m4-19) behind-the-ear HA. The participants acted as their own control in a total of seven conditions: (1) bimodal with own HA, (2) CI only, (3) own HA alone, (4) bimodal new HA LFT-off, (5) new HA LFT-off, (6) bimodal new HA LFT-on, and (7) new HA LFT-on. Data Collection and Analysis: Monosyllabic words in quiet and the Swedish version of Hearing in Noise Test (HINT) were used as speech test materials. Stimuli were presented in sound field at a speech level of 65 dB sound pressure level (SPL) via a loudspeaker at a distance of 1 m from the participant in a sound-treated room. The SSQ was administered in each session evaluating the three bimodal conditions. SPSS software was used for statistical analyses. General linear model (GLM) analysis of variance for repeated measures was performed and followed with Bonferroni-adjusted post hoc pairwise comparisons. Results: Participants performed better with CI only than with HA alone, and the bimodal conditions were superior to the CI alone. No significant differences (p > .05) were observed when comparing the LFT-on with LFT-off regardless of whether the use of CI was included in the different listening conditions in objective and subjective measurements. Conclusions: The results suggest an advantage for CI patients with a HA in the opposite ear, and that the LFT neither degraded nor enhanced speech performance in conjunction with a CI in quiet or in noise in comparison to when it was deactivated.
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