共查询到20条相似文献，搜索用时 31 毫秒
1.
Christian Mehl Matthias Kern Friederike Neumann Telse Bähr Jörg Wiltfang Volker Gassling 《Journal of Zhejiang University. Science. B》2018,19(7):525-534
Objective
The aim of the current study was to evaluate the effect of ultraviolet (UV) photofunctionalization of dental titanium implants with exposure to the oral cavity on osseointegration in an animal model.Methods
Forty-eight titanium implants (Camlog® Conelog® 4.3 mmx9.0 mm) were placed epicrestally into the edentulous jaws of three minipigs and implant stability was assessed by measuring the implant stability quotient (ISQ). Prior to implantation half of the implants were photofunctionalized with intense UV-light. After three months, the implants were exposed and ISQ was measured again. After six months of implant exposure, the minipigs were sacrificed and the harvested specimens were analyzed using histomorphometric, light, and fluorescence microscopy.Main results
Forty-two of 48 implants osseointegrated. The overall mean bone-implant contact area (BIC) was (64±22)%. No significant differences were found in BIC or ISQ value (multivariate analysis of variance (MANOVA), P>0.05) between implants with and without exposure to UV photofunctionalization.Conclusions
No significant effects were observed on osseointegration of dental titanium implants nine months after exposure of UV photofunctionalization.2.
Shi-fang ZHAO Wen-jing DONG Qiao-hong JIANG Fu-ming HE Xiao-xiang WANG Guo-li YANG 《Journal of Zhejiang University. Science. B》2013,14(6):518-525
Objective:The purpose of this study was to investigate the effects of a zinc-substituted nano-hydroxyapatite(Zn-HA) coating,applied by an electrochemical process,on implant osseointegraton in a rabbit model.Methods:A Zn-HA coating or an HA coating was deposited using an electrochemical process.Surface morphology was examined using field-emission scanning electron microscopy.The crystal structure and chemical composition of the coatings were examined using an X-ray diffractometer(XRD) and Fourier transform infrared spectroscopy(FTIR).A total of 78 implants were inserted into femurs and tibias of rabbits.After two,four,and eight weeks,femurs and tibias were retrieved and prepared for histomorphometric evaluation and removal torque(RTQ) tests.Results:Rod-like HA crystals appeared on both implant surfaces.The dimensions of the Zn-HA crystals seemed to be smaller than those of HA.XRD patterns showed that the peaks of both coatings matched well with standard HA patterns.FTIR spectra showed that both coatings consisted of HA crystals.The Zn-HA coating significantly improved the bone area within all threads after four and eight weeks(P<0.05),the bone to implant contact(BIC) at four weeks(P<0.05),and RTQ values after four and eight weeks(P<0.05).Conclusions:The study showed that an electrochemically deposited Zn-HA coating has potential for improving bone integration with an implant surface. 相似文献
3.
用真空离子镀技术在L316医用不锈钢表面镀上一层氨化钛薄膜,制成氮化钛-不锈钢复合体,并以纯钛及医用L316不锈钢作对照,植入60只小白鼠的胫骨内．经扫描电镜等观察结果表明：氮化钛-不锈钢复合体及纯钛材料与骨之间都形成骨整合及纤维整合界面,但是,氮化钛-不锈钢复合体比纯钛材料骨性结合界面形成早,成骨活跃 相似文献
4.
5.
Perception of suprasegmental features of speech by children with cochlear implants and children with hearing AIDS 总被引：1，自引：0，他引：1
This study assessed perception of suprasegmental features of speech by 30 prelingual children with sensorineural hearing loss. Ten children had cochlear implants (CIs), and 20 children wore hearing aids (HA): 10 with severe hearing loss and 10 with profound hearing loss. Perception of intonation, syllable stress, word emphasis, and word pattern was assessed. Results revealed that the two HA groups significantly outperformed the CI group in perceiving both intonation and stress. Within each group, word pattern was perceived best, and then intonation and emphasis, with syllable stress perceived poorest. No significant correlation emerged between age at implantation and perception of the various suprasegmental features, possibly due to participants' relatively late age at implantation. Results indicated that CI use did not show an advantage over HA use in the perception of suprasegmental features of speech. Future research should continue to explore variables that might improve this perception. 相似文献
6.
The cochlear implant, a bionic technology that restores sound sensation in some patients, has become ethically controversial in the 20 years since its introduction. This controversy recently has entered American entertainment culture, with the issue of pediatric implants emerging in episodes of popular TV programs. This pilot study examines the effects of one such TV episode on the attitudes of hearing college students with minimal prior exposure to the controversy, using a posttest-only control group design. The control group (N = 17) watched an unrelated entertainment video and filled out an original 10-item attitude scale. The treatment group (N = 18), which viewed an episode of the dramatic series Gideon's Crossing addressing the cochlear implant issue, also filled out the attitude scale. A t test was applied, and it was determined that no significant difference existed between the two groups' attitudes regarding pediatric cochlear implants. Although there was wide variability on individual items, overall scores indicated that both groups were neutral, or undecided, regarding cochlear implantation in children. 相似文献
7.
Yang RN Ye F Cheng LJ Wang JJ Lu XF Shi YJ Fan HS Zhang XD Bu H 《Journal of Zhejiang University. Science. B》2011,12(7):582-590
The osteoinduction of porous biphasic calcium phosphate ceramics (BCP) has been widely reported and documented, but little
research has been performed on rodent animals, e.g., mice. In this study, we report osteoinduction in a mouse model. Thirty
mice were divided into two groups. BCP materials (Sample A) and control ceramics (Sample B) were implanted into the leg muscle,
respectively. Five mice in each group were killed at 15, 30, and 45 d after surgery. Sample A and Sample B were harvested
and used for hematoxylin and eosin (HE) staining, immunohistochemistry (IHC) staining, and Alizarin Red S staining to check
bone formation in the biomaterials. Histological analysis showed that no bone tissue was formed 15 d after implantation (0/5)
in either of the two groups. Newly-formed bone tissues were observed in Sample A at 30 d (5/5) and 45 d (5/5) after implantation;
the average amounts of newly-formed bone tissues were approximately 5.2% and 8.6%, respectively. However, we did not see any
bone tissue in Sample B until 45 d after implantation. Bone-related molecular makers such as bone morphogenesis protein-2
(BMP-2), collagen type I, and osteopontin were detected by IHC staining in Sample A 30 d after implantation. In addition,
the newly-formed bone was also confirmed by Alizarin Red S staining. Because this is the report of osteoinduction in the rodent
animal on which all the biotechnologies were available, our results may contribute to further mechanism research. 相似文献
8.
Binaural hearing in cochlear implant (CI) users can be achieved either by bilateral implantation or bimodally with a contralateral hearing aid (HA). Binaural-bimodal hearing has the advantage of complementing the high-frequency electric information from the CI by low-frequency acoustic information from the HA. We examined the contribution of a contralateral HA in 25 adult implantees to their perception of fundamental frequency-cued speech characteristics (initial consonant voicing, intonation, and emotions). Testing with CI alone, HA alone, and bimodal hearing showed that all three characteristics were best perceived under the bimodal condition. Significant differences were recorded between bimodal and HA conditions in the initial voicing test, between bimodal and CI conditions in the intonation test, and between both bimodal and CI conditions and between bimodal and HA conditions in the emotion-in-speech test. These findings confirmed that such binaural-bimodal hearing enhances perception of these speech characteristics and suggest that implantees with residual hearing in the contralateral ear may benefit from a HA in that ear. 相似文献
9.
The phonological awareness (PA), vocabulary, and word reading abilities of 19 children with cochlear implants (CI) were assessed. Nine children had an implant early (between 2 and 3.6 years) and 10 had an implant later (between 5 and 7 years). Participants were tested twice over a 12-month period on syllable, rhyme, and phoneme awareness (see James et al., 2005). Performance of CI users was compared against younger hearing children matched for reading level. Two standardized assessments of vocabulary and single word reading were administered. As a group, the children fitted early had better performance outcomes on PA, vocabulary, and reading compared to hearing benchmark groups. The early group had significant growth on rhyme awareness, whereas the late group showed no significant gains in PA over time. There was wide individual variation in performance and growth in the CI users. Two participants with the best overall development were both fitted with an implant late in childhood. 相似文献
10.
吴立东 《浙江大学学报(A卷英文版)》2004,5(10):1270-1278
Objective: To observe the accuracy of femoral preparation and the position of the cementless prosthesis in femoral cavity, and to compare the results between the computer-assisted surgical group (CASPAR) and the conventional group. Methods: Ten femoral components were implanted either manually or by CASPAR in cadaver femurs. The specimens were cut to 3 mm thick slices. Microradiograms of every slice were sent to a computer for analysis with special software (IDL). The gaps and the medullary cavities between component and bone, the direct bone contact area of the implant surface,the gap width and the percentage of gap and bone contact area were measured in every slice. Results: In the proximal implant coated with HA of the CASPAR group, the average percentage of bone contact reached 93.2% (ranging from 87.6% to 99.7%); the average gap percentage was 2.9% (ranging from 0.3% to 7.8%); the maximum gap width was 0.81 mm and the average gap width was only 0.20 mm. While in the conventional group, the average percentage of bone contact reached 60.1% (ranging from 49.2% to 70.4%); the average gap percentage was 32.8% (ranging from 25.1% to 39.9%); the maximum gap width was 2.97 mm and the average gap width was 0.77 mm. The average gap around the implant in the CASPAR group was only 9% of that in the manual group; the maximum and average gap widths were only about 26% of those in the manual group. On the other hand, the CASPAR group showed 33% higher bone contact than the manual group. Conclusion: With the use of robotics-assisted system, significant progress can be achieved for femoral preparation in total hip arthroplasty. 相似文献
11.
Objective: To observe the accuracy of femoral preparation and the position of the cementless prosthesis in femoral cavity, and to compare the results between the computer-assisted surgical group (CASPAR) and the conventional group. Methods: Ten femoral components were implanted either manually or by CASPAR in cadaver femurs. The specimens were cut to 3 mm thick slices. Microradiograms of every slice were sent to a computer for analysis with special software (IDL). The gaps and the medullary cavities between component and bone, the direct bone contact area of the implant surface, the gap width and the percentage of gap and bone contact area were measured in every slice. Results: In the proximal implant coated with HA of the CASPAR group, the average percentage of bone contact reached 93.2% (ranging from 87.6% to 99.7%); the average gap percentage was 2.9% (ranging from 0.3% to 7.8%); the maximum gap width was 0.81 mm and the average gap width was only 0.20 mm. While in the conventional group, the average 相似文献
12.
This article presents a critical analysis of empirical studies assessing literacy and other domains of academic achievement among children with cochlear implants. A variety of recent studies have demonstrated benefits to hearing, language, and speech from implants, leading to assumptions that early implantation and longer periods of implant should be associated with higher reading and academic achievement. This review, however, reveals that although there are clear benefits of cochlear implantation to achievement in young deaf children, empirical results have been somewhat variable. Examination of the literature with regard to reading achievement suggests that the lack of consistent findings might be the result of frequent failures to control potentially confounding variables such as age of implantation, language skills prior to implantation, reading ability prior to implantation, and consistency of implant use. Studies of academic achievement beyond reading are relatively rare, and the extent to which performance in such domains is mediated by reading abilities or directly influenced by hearing, language, and speech remains unclear. Considerations of methodological shortcomings in existing research as well as theoretical and practical questions yet to be addressed provide direction for future research. 相似文献
13.
Bing Zhang Pei-biao Zhang Zong-liang Wang Zhong-wen Lyu Han Wu 《Journal of Zhejiang University. Science. B》2017,18(11):963-976
Objective
A new therapeutic strategy using nanocomposite scaffolds of grafted hydroxyapatite (g-HA)/poly(lactide-co-glycolide) (PLGA) carried with autologous mesenchymal stem cells (MSCs) and bone morphogenetic protein-2 (BMP-2) was assessed for the therapy of critical bone defects. At the same time, tissue response and in vivo mineralization of tissue-engineered implants were investigated.Methods
A composite scaffold of PLGA and g-HA was fabricated by the solvent casting and particulate-leaching method. The tissue-engineered implants were prepared by seeding the scaffolds with autologous bone marrow MSCs in vitro. Then, mineralization and osteogenesis were observed by intramuscular implantation, as well as the repair of the critical radius defects in rabbits.Results
After eight weeks post-surgery, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) revealed that g-HA/PLGA had a better interface of tissue response and higher mineralization than PLGA. Apatite particles were formed and varied both in macropores and micropores of g-HA/PLGA. Computer radiographs and histological analysis revealed that there were more and more quickly formed new bone formations and better fusion in the bone defect areas of g-HA/PLGA at 2–8 weeks post-surgery. Typical bone synostosis between the implant and bone tissue was found in g-HA/PLGA, while only fibrous tissues formed in PLGA.Conclusions
The incorporation of g-HA mainly improved mineralization and bone formation compared with PLGA. The application of MSCs can enhance bone formation and mineralization in PLGA scaffolds compared with cell-free scaffolds. Furthermore, it can accelerate the absorption of scaffolds compared with composite scaffolds.14.
Within the framework of a longitudinal study of deaf children with cochlear implants, 11 children with implants were interviewed. The objective was to shed light on what it is like for a child to use a cochlear implant, based on these children's own experience with implants, which ranged from 5.0 to 7.5 years. Six of the children were in schools for the deaf, five in regular classes. All but one used an implant daily. The children appreciated that an implant enabled them to perceive sounds in the environment. Some of the children in regular classes could take part in one-to-one conversations with teachers but had difficulty following teaching and discussions. This observation was consistent with what the children's parents and teachers had maintained. Peer interaction was said to be best when other children had the use of at least some signs. 相似文献
15.
Study on the neurotoxic effects of low-level lead exposure in rats 总被引：10，自引：0，他引：10
Objective: To investigate effects of developmental lead exposure on nitric oxide synthase (NOS) activity in different brain regions and on N-methyl-D-aspartate (NMDA) receptor mRNA expression in the hippocampus of rats. On the basis of these observations, we explored possible mechanisms by which lead exposure leads to impaired learning and memorizing abilities in children. Methods: A series of rat animal models exposed to low levels of lead during the developing period was established (drinking water containing 0.025%, 0.05% and 0.075% lead acetate). NOS activities in the hippocampus, the cerebral cortex, the cerebellum and the brain stem were determined with fluorescence measurement and levels of mRNA expression of the NMDA receptor 2A (NR2A) subunit and NMDA receptor 2B (NR2B) subunit in the rat hippocampus were measured with Retro-translation (RT-PCR). Results: There were no differences in the body weight of rat pups between any of the groups at any given time (P>0.05). The blood lead level of Pb-exposed rat pups showed a systematic pattern of change: at 14 d of age, it was lower than that at 7 d of age, then rising to the peak level at 21 d and finally falling to lower levels at 28 d. The hippocampal NOS activities of lead-exposed groups were all lower than that of the control group on the 21st and 28th day (P<0.01). NOS activities in the cerebellum of lead-exposed groups were all lower than that of the control group on the 21st and 28th day (P<0.001) and the NOS activity of the 0.025% group was significantly lower than that of the 0.05% and 0.075% groups on the 28th day (P<0.05). NOS activity in the cerebral cortex of the 0.075% group was significantly lower than that of the control, 0.025% and 0.05% groups on the four day spans (P<0.001). There was no significant difference of NOS activity in the brain stem between any lead-exposed group and the control group on the four day spans. In the 0.05% and the 0.075% groups, the level of NR2A mRNA expression was higher than that in the control group at 7 d and 14 d of age (P<0.05). In the 0.025% group, the level of NR2A was found to be higher than that in the control group at 7 d of age only (P<0.05). No significant differences were found for the levels of NR2B mRNA expression between any of the groups at any given time. Conclusions: NOS activity in the hippocampus, the cerebral cortex and the cerebellum are inhibited by lead exposure. The degree of the inhibitory effect depends on the time span of exposure and the lead concentration. Developmental low-level lead exposure was found to raise the level of NR2A mRNA expression in the hippocampus of rats. Developmental low-level lead exposure does not affect the level of NR2B mRNA expression in the hippocampus. 相似文献
16.
Psychosocial factors, including socioemotional well-being, peer relationships, and social inclusion with hearing and deaf peers, are increasingly becoming a focus of research investigating children with cochlear implants. The study reported here extends the largely quantitative findings of previous research through a qualitative analysis of interviews with parents, teachers, and pediatric cochlear implant users themselves in three eastern states of Australia. We interviewed 24 parents, 15 teachers, and 11 children and adolescents. The findings displayed commonalities across the three groups of participants, indicating positive experiences around the children's psychosocial development with their cochlear implants, but also ongoing difficulties communicating in groups of people and problems related to social skills. Some children had little contact with other deaf children (with or without cochlear implants) despite parents and teachers perceiving such contact beneficial. Children attending schools where there were other deaf children valued friendships with both deaf and hearing peers. Adolescence was a particularly difficult time for some as they struggled with feelings of self-consciousness about their deafness and external cochlear implant equipment and worries around friendships, dating, and their future place in the world. Recommendations for practice and further research are made. 相似文献
17.
18.
Neuropsychological correlates of vocabulary, reading, and working memory in deaf children with cochlear implants 总被引：1，自引：0，他引：1
The performance of deaf children with cochlear implants was assessed using measures standardized on hearing children. To investigate nonverbal cognitive and sensorimotor processes associated with postimplant variability, five selected sensorimotor and visuospatial subtests from A Developmental Neuropsychological Assessment (NEPSY) were compared with standardized vocabulary, reading, and digit span measures. Participants were 26 deaf children, ages 6-14 years, who received a cochlear implant between ages 1 and 6 years; duration of implant use ranged from 3 to 11 years. Results indicated significant correlations between standard scores on the Design Copying subtest of the NEPSY and standard scores on vocabulary comprehension, reading, and digit span measures. The results contribute to our understanding of the benefits of cochlear implantation and cognitive processes that may support postimplant language and academic functioning. 相似文献
19.
Objective： This study is aimed at describing the clinical outcome of amniotic membrane transplantation for exposure of porous sphere implants. Methods： A retrospective review of consecutive cases of porous sphere orbital implant exposure was carried out. Eight cases were presented between May 2004 and Oct. 2006 （5 males, 3 females; mean age 44.5 years）. Six had enucleation and two had evisceration. Exposure occurred in two primary and six secondary. Orbital implant diameter was 22 mm in seven cases and 20 mm in one case. Six patients are with hydroxyapatite and two with high-density porous polyethylene （Medpor） orbital implants. The mean time from implantation to exposure was 1.1 months （range 0.8-2 months）. All patients required surgical intervention. Results： The time of follow-up ranged from 3.0 to 28.0 months （mean 16.5 months）. Amniotic membrane grafting successfully closed the defect without re-exposure in all of these patients. The grafts were left bare with a mean time to conjunctiva of about 1 month （range 0.8-1.5 months）. Conclusion： Exposed porous sphere implants were treated successfully with amniotic membrane graft in all of patients. The graft is easy to harvest. This technique is useful, dose not lead to prolonged socket inflammation and infection, and it is valuable application extensively. 相似文献
20.
Connor CM 《Journal of deaf studies and deaf education》2006,11(4):449-460
The purpose of this longitudinal case study was to closely examine one deaf child's experience with a cochlear implant and his speech, language, and communication skills from kindergarten through middle and high school using both developmental and sociocultural frameworks. The target child was one of the first children to receive a cochlear implant in the United States in 1988, when he was 5 years of age. The developmental analysis revealed that prior to receiving a cochlear implant the child demonstrated profound delays in speech and language skill development. His speech and language skills grew slowly during the first 3-4 years following implantation, very rapidly from about 5 through 7 years postimplantation, then slowed to rates that were highly similar to same-age peers with normal hearing. The sociocultural analysis revealed that the child's communicative competence improved; that he used sign language but use of sign language decreased as his oral communication skills improved; that as his oral communication skills improved, the adults talked and directed the topic of conversation less frequently; and that topics became less concrete and more personal over time. The results of this study indicate that we may learn more about how to support children who use cochlear implants by examining what they are saying as well as how they are saying it. 相似文献