Orchiectomy is the recommended treatment for many testicular conditions.However,testicular prosthesis placement is not always performed for different reasons.In this study,we aimed to evaluate patients'opinions an...Orchiectomy is the recommended treatment for many testicular conditions.However,testicular prosthesis placement is not always performed for different reasons.In this study,we aimed to evaluate patients'opinions and the impact on sexual function and quality of life.This retrospective observational single-center study included patients who underwent orchiectomy between January 2014 and December 2020 at the Department of Urology,Braga's Hospital(Braga,Portugal),where testicular implants were always available and the decision to undergo the procedure was made fully independent of cost.Patients completed four questionnaires that assessed demographic data,satisfaction,self-esteem,and sexual function.Of the 96 patients who underwent orchidectomy,59 replied to the questionnaires,and of these patients,86.4%decided to undergo silicone-based testicular prostheses implantation.The remaining 13.6%refused the implant based on concerns about complications(37.5%),because they felt that it was unnecessary(37.5%),or because it was not offered by the doctor(25.0%).Overall,96.1%of these patients were satisfied with the implant;however,25.5%classified it as"too firm".No statistically significant differences were found in sexual function(all P>0.05).However,it can be observed that there are more patients with prostheses presenting normal sexual activity compared to patients without prostheses(74.0%vs 50.0%),and none of them reported severe erectile dysfunction(0 vs 16.7%).Regarding self-esteem,both patients with and without prostheses present very similar average scores with no statistically significant differences.The present study highlights the highest level of satisfaction among patients who received testicular prostheses.Testicular prostheses implantation is a safe procedure that does not hamper sexual function after orchiectomy.展开更多
Background:Stapes prostheses play a crucial role in improving auditory performance and facilitating the patient's reintegration into social life.However,determining the ideal characteristics of a prosthesis and id...Background:Stapes prostheses play a crucial role in improving auditory performance and facilitating the patient's reintegration into social life.However,determining the ideal characteristics of a prosthesis and identifying the best commercially available option remain challenging.This study aims to compare the outcomes of two different types of prostheses:the MatriX Stapes Prosthesis and the new mAXIS Stapes Prosthesis.Methods:A prospective study was conducted on patients diagnosed with suspected otosclerosis who underwent stapedotomy,receiving either the MatriX or m AXIS prosthesis randomly during surgery.Postoperative follow-ups were conducted for at least one year.Audiometric evaluations were analyzed using statistical tests.Additionally,a systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Metaanalyses(PRISMA)statement.Results:The prospective study included 84 patients,divided into two groups(G1:MatriX,G2:mAXIS).The auditory results were satisfactory for both prostheses,demonstrating their effectiveness in improving hearing thresholds.We observed a gain for air conduction threshold of 26.2 dB vs 21.2 dB with an ABG closure of 20.7 dB vs and 21.2 dB in G1 and G2 respectively.The literature review encompassed 15studies,revealing overall positive outcomes with different prosthetic materials.Conclusions:The study revealed effective auditory improvement with both prostheses,yet no statistically significant differences in air-bone gap closure or average hearing gain.Titanium emerged as the preferred material due to its biocompatibility,lightweight nature,and stability under magnetic resonance imaging.The mAXIS prosthesis is introduced as a cost-effective alternative with favorable intraoperative features.展开更多
The surgical techniques used by Austoni and Egydio in the treatment of Peyronie＇s disease are based on geometric principles. The aim of this paper is to report our multicentric experience and technical changes to Aus...The surgical techniques used by Austoni and Egydio in the treatment of Peyronie＇s disease are based on geometric principles. The aim of this paper is to report our multicentric experience and technical changes to Austoni＇s original technique, focusing on several tips and tricks to make this technique easy to perform, even by less experienced practitioners. We performed operations in three different Italian institutions. We implanted a small soft Virilis I~ axial prostheses （Ф 7 Fr.）, using a bovine pericardium collagen matrix patch （Hydrix） to cover the defect in the tunica albuginea. Sixty patients with a mean age of 58 years （range 44-76 years） underwent surgery between September 2005 and January 2010. After surgery, mean lengthening of the shaft was 2 cm （range 1.2-2.3 cm） with complete correction of penile recurvatum. Thirty-nine patients resumed sexual activity 60 days later, 14 after 90 days and 7 after 120 days. The international index of erectile function （IIEF） score was 15.5 before surgery and it improved to 23 at 12 and 24 months after surgery. Furthermore, the visual analogue scale （VAS） showed good results in terms of the recovery of natural sexual intercourse （over 80% of couples） and of the original length and girth of the penis. The soft implant we used takes advantage of erection that occurs spontaneously, using the residual erection of the spared cavernous tissue. The method is easy to learn and reproducible, and the use of pericardium speeds up the operation, while also covering large defects of the tunica albuginea that result from complex recurvatum.展开更多
The microstructure and properties of a series of binary Ti-Nb alloys for dental prostheses with niobium contents ranging from 5% to 20% were investigated. The experimental results indicate that the crystal structure a...The microstructure and properties of a series of binary Ti-Nb alloys for dental prostheses with niobium contents ranging from 5% to 20% were investigated. The experimental results indicate that the crystal structure and morphology of Ti-Nb alloys are sensitive to their niobium contents. When Nb content is 5%, the acicular α crystal grain is observed. When Nb content is 10%, the coarse equiaxed crystal grain and the fine, acicular α crystal grain are observed. When Nb content is 15%, only the α equiaxed crystal grain is observed. When the alloy contains 20%Nb, the equiaxed and dendritic α crystal grain are observed. For Ti-Nb alloys, the increase of Nb content modifies the microstructure of Ti-Nb alloys significantly and decreases their compression elastic modulus, in which Ti-20Nb alloy shows the largest compression strength and Ti-5Nb alloy shows the best plasticity. The dry wear resistance of Ti-Nb alloys against Gr15 ball was investigated on CJS111A ball-disk wear instrument. For Ti-Nb alloys, Ti-10Nb alloy shows a smallest steady friction coefficient, Ti-5Nb alloy shows the smallest wear depth and best wear resistance, and Ti-15Nb alloy shows the largest wear depth and worst wear resistance. The phenomenon of furrow cut happens and furrows form during wear tests.展开更多
Spinal cord injury（SCI）is a debilitating condition that affects more than 2.5 million individuals worldwide（Thuret et al.,2006）.In addition to its devastating effects on the individual,this disease is a heavy burd...Spinal cord injury（SCI）is a debilitating condition that affects more than 2.5 million individuals worldwide（Thuret et al.,2006）.In addition to its devastating effects on the individual,this disease is a heavy burden to the society in terms of health care costs, which are estimated in billions of dollars annually in most developed countries （Cadotte and Fehlings, 2011）.展开更多
There are some problems in the vascular prostheses, which influence the health of the patients. This paper aims to the radial compliance of three kinds of vascular prostheses and the pig＇s carotid based on the dynami...There are some problems in the vascular prostheses, which influence the health of the patients. This paper aims to the radial compliance of three kinds of vascular prostheses and the pig＇s carotid based on the dynamic-simulated condition. The radial compliance of knitted structure vascular prostheses with crimps ranged from 2.52% to 0.94%/100 mmHg, which was superior to e-FFFE and woven prostheses＇, ranged from 0.73% to 0.31%/100 mmHg and from 0.81% to 0.22%/100 mmHg. But comparing with the radial compliance of pig＇s carotid, ranged from 7.21% to 10.04% /100 mmHg, there was a big gap between them. And also the trend of the radial compliance of vascular prostheses was different from the real pig＇s carotid. There is a lot of work left to improve the radial compliance, not only to change the vascular prostheses＇ compliance, but also to meet with the real vascular.展开更多
Small diameter arterial prostheses were required to treat coronary and cerebrovascular arterial diseases. The diameters of the artificial blood vessels should match the diameters of the host arteries. Besides,the mech...Small diameter arterial prostheses were required to treat coronary and cerebrovascular arterial diseases. The diameters of the artificial blood vessels should match the diameters of the host arteries. Besides,the mechanical properties of the arterial prostheses should be strong enough to endure the forces in the body after implantation. In this study,silk and polyester were woven into small diameter arterial prostheses and the dimensional and mechanical properties,as well as the water permeability,were investigated. The woven samples had an inner diameter ranging from 3. 65 to 3. 94mm. The wall thickness of the samples ranged from 0. 26 to 0. 28mm. Compared with polytetrafiuoroethylene( ePTFE) commercial devices,whose probe bursting strength was measured to be 15. 64 N /mm2,the woven samples had superior strength values ranging from20. 53 to 28. 97 N /mm2. In addition,the radial compliance of the woven samples was found to lie between the ePTFE sample and the pig's carotid artery,and the water permeability of all the woven samples was less than 300 mL /( cm2·min) which indicated that these woven samples could be implanted without preclotting.展开更多
The general object of research is to design new idea of the semi-biodegradable,multilayered vascular prosthesis used for the reconstruction of significantly small diameter vascular vessels( microreconstruction). The p...The general object of research is to design new idea of the semi-biodegradable,multilayered vascular prosthesis used for the reconstruction of significantly small diameter vascular vessels( microreconstruction). The paper studies the selection of appropriate sterilization technique for resorbable tubular structures made of poly( L-lactide-co-glicolide)( PLAGA) and nonbiodegradable tubular structures made of polypropylene( PP). The designed grafts are characterized by the physical properties as well as mechanical properties according to ISO 7198 ∶ 1998 Standard.Moreover,the process of the grafts fabrication will be explained considering the stages affected the critical properties of the elaborated textile implants. The increase of PLAGA melt-electrospun tubular structures mechanical properties was observed due to the thermal stabilization use. The ethylene oxide( EO) and steam sterilization had a destructive effect on the designed PLAGA meltelectrospun tubular, fibrous structures, whereas the irradiation yielded in the changes in mechanical and physical properties on the acceptable level,taking into account the future clinical applications.展开更多
In the experiment, we inserted the implants coated with TC4 fibers and particles into the bones of dogs.The histological characters of the bone ingrowth and the state of bone remodelling at interface were observed. An...In the experiment, we inserted the implants coated with TC4 fibers and particles into the bones of dogs.The histological characters of the bone ingrowth and the state of bone remodelling at interface were observed. And then the whole course of the fatigue injuries accumulation at the interface was monitored by scanning electron microscopy equipped with fatigue stage. Experiments show that the collagen fibers of bone interweave in the porosity of implants, which were strengthened by hydroxyapatite crystal. The collagen fibers were bound to the porous layer implant and the binding strength was enhanced by hydroxyapatite crystal. The remodelling state of bone in pores of implant and around the interface play a key role in determining the fatigue strength and the life span of the interface between bone and implant. Therefore, we consider that the interlocking fixation between bone and implant can be more exactly explained as binding mechanism.展开更多
The aim of this work was to assess the preliminary anatomical and functional results of patients to establish prospects. Materials and method: We report here the preliminary results of a retrospective mono-centric, ho...The aim of this work was to assess the preliminary anatomical and functional results of patients to establish prospects. Materials and method: We report here the preliminary results of a retrospective mono-centric, homogeneous and continuous series, of 21 non-cemented total hip implants, implanted from January 2011 to December 2014. The mean follow-up time was 24 months. The patients were evaluated by Harris’s hip at the last follow-up. Results: The mean age of the intervention was 30 years. In our series, we observed a male predominance (60% of cases). Clinically, the Harris score varied significantly from 52.6 ± 11.4 pre-operatively to 85.1 ± 5.1 during the last follow-up visit. Among the items in the score, pain was the parameter that showed the greatest improvement. Thigh pain was observed in only one patient operated on the two sides. At the level of radiology, the femoral implant showed great stability. Bone resorption was suspected in 14 cases (66.66%), and confirmed in 4 cases (19.04%) with excellent bone remodeling, illustrated by the Engh and Massin scores. A loosening and a prosthetic dislocation was observed in a patient (4.76%). Any heterotopic ossification was observed. Conclusion: Our study confirmed good clinical and radiological results of the non-cemented hip prosthesis series in young patients. The rates of aseptic loosening, acetabular edges or osteolysis are low and stable over time.展开更多
The aim of this retrospective study was to compare the different anticoagulation regimens used in pregnant women with prosthetic heart valves. We reviewed 86 pregnancies in 57 women from 1987 to 2011. The patients wer...The aim of this retrospective study was to compare the different anticoagulation regimens used in pregnant women with prosthetic heart valves. We reviewed 86 pregnancies in 57 women from 1987 to 2011. The patients were divided into two groups: group A (39 pregnancies) had oral acenocoumarol throughout pregnancy;and in group B (47 pregnancies), acenocoumarol was replaced by subcutaneous heparin during the first trimester. Both groups received heparin at the time of delivery. The valves replaced were mitral (59.65%), aortic (12.28%), or both (28.07%). 74 pregnancies (86.04%) resulted in live births, 9 (10.46%) had stillbirths, 1 (1.16%) had spontaneous abortion and 2 (2.32%) underwent therapeutic abortions. The live birth rate was higher in women on heparin (87.23%) compared with those on acenocoumarol (84.61%). No malformations appeared in the 74 newborns, except for one case of hydrocephalus. There was one maternal death due to acute mitral valvular thrombosis while on heparin in the first trimester. Hemorrhagic complications occurred in 13 patients in the postpartum period, 4 of whom required transfusion. No anticoagulant regimen can be said to be entirely safe for use during pregnancy as there is a degree of risk with each regimen. Heparin does not offer a clear advantage over oral anticoagulation in the pregnancy outcome.展开更多
<span><span style="white-space:nowrap;font-family:Verdana;"><strong>Background:</strong></span><strong><span style="font-family:Verdana;"></span><...<span><span style="white-space:nowrap;font-family:Verdana;"><strong>Background:</strong></span><strong><span style="font-family:Verdana;"></span></strong></span><span>Perforation of the oesophagus is a serious condition. Most of them are iatrogenic and are associated with significant morbidity and mortality, especially with late diagnosis. </span><b><span style="font-family:Verdana;">Aim:</span></b><span style="font-family:Verdana;"> To prospectively analyse the results of the endoscopic management of iatrogenic perforations in oesophageal neoplasia, through the immediate insertion of a covered self-expanding prosthesis (CSES). </span><b><span style="font-family:Verdana;">Materials and Methods:</span></b><span style="font-family:Verdana;"> Between 01.01.2006 and 12.30.2016, a series of 19 consecutive patients attended the Teaching Unit of Endoscopic Surgery of the Regional de Concepción Hospital, Chile, with the diagnosis of oesophageal neoplasia confirmed by biopsy were prospectively studied. All were subjected to a prior evaluation by the oncology team and subsequently referred for endoscopic palliative management of dysphagia. The average age was 77 ± 9.3 years, 8 (42.1%) were female and 11 (57.9%) were male. In 17 patients (89.5%) the stenosis compromised the oesophagus, in 2 (10.5%) the gastro-oesophageal junction, 16 had a squamous carcinoma (84.2%) and 3 an adenocarcinoma (15.8%). </span><b><span style="font-family:Verdana;">Results: </span></b><span style="font-family:Verdana;">Perforation was diagnosed during the procedure in 18 patients (94.7%) and in 1 (5.3%) 22 hours later. Follow-up was done for a minimum of 90 days or until death. The prostheses were inserted successfully in all cases. The immediate evolution was satisfactory in 12 patients (63.2%). In the rest (36.8%), 18 complications appeared. The most frequent were retrosternal pain, subcutaneous emphysema and fever. The early evolution was satisfactory in 12/19 cases (63.2%). Complication was evidenced in 7 (36.8%), the most frequent was retrosternal pain (36.8%). Fever occurred in 3 (15.8%), pleural effusion in 3 (15.8%) and mediastinitis in 2 of these. The prosthesis was kept in situ as a definitive palliation method for neoplas</span><span><span style="font-family:Verdana;">tic dysphagia. In 10 of the 18 cases that survived more than a month, there were late complications (55.6%), none of them associated with the perforation itself. The only death (5.3%) was due to an oesophagus-pleural fistula, associated with an early prosthetic migration. Recovery of the oral intake occurred, on average, at 3.7 days. The hospital stay averaged 9.6 days. </span><b><span style="font-family:Verdana;">Conclusion: </span></b><span style="font-family:Verdana;">The use of CSES for the treatment of iatrogenic oesophageal perforations in the context of neoplasia, is a safe and effective method, with low morbidity, adequate recovery of the oral intake and prompt discharge from hospital.</span></span>展开更多
The Ni-Cr-Mo alloys have been used as dental prostheses because they own a good mechanical strength, high corrosion resistance and even to be economically viable. These alloys corrosion protection against in salt solu...The Ni-Cr-Mo alloys have been used as dental prostheses because they own a good mechanical strength, high corrosion resistance and even to be economically viable. These alloys corrosion protection against in salt solutions typical of physiological media is due to passivation phenomenon with an oxide surface layer formation, mainly chromium oxides. This protective film, subjected to a mechanical stress in a corrosive environment, can partially dissolve by releasing ions, which have deleterious effects in a human body. Fluoride ions, existing in hygiene products, change the buccal environment and their presence may enable a localized corrosion process initiation. The aim of this work has been to investigate the chemical composition influence of three alloys in corrosion resistance to: A (Ni-73% Cr-14% Mo-8.5% Be-1.8% Al-1.8%), B (Ni-61% Cr-25% Mo-10.5% Si-1.5%) and C (Ni-65% Cr-22.5% Mo-9.5%) in media containing fluorides that simulate mouthwashes solution. The study has been done in a 0.05% NaF solution, pH 6, at 37°C using electrochemical techniques. The alloy with the highest nickel and the lowest chromium content is not passive in the middle studied, showing a continuous increase in current density with the potential increasing, while the other alloys show passivation range of 600 mV and passive current density of about 10-6 A/cm2.展开更多
The size of the blind population in 2015 was estimated to be approximately 36 million（Bourne et al.,2017）.According to the predictions by Bourne and co-workers,the number of the visually impaired is expected to reac...The size of the blind population in 2015 was estimated to be approximately 36 million（Bourne et al.,2017）.According to the predictions by Bourne and co-workers,the number of the visually impaired is expected to reach nearly 100 million by 2050.展开更多
Open oro-nasal defects resulting after oral tumor resection need structural and functional rehabilitation using dental prostheses. Conventional removable prostheses have usually been indicated and performed for prosth...Open oro-nasal defects resulting after oral tumor resection need structural and functional rehabilitation using dental prostheses. Conventional removable prostheses have usually been indicated and performed for prosthodontics. When the patient has an edentulous maxilla, the unfavorable stability of the prosthesis will cause dysfunction of mastication and pronunciation. To achieve improvement of the impaired functional situation, implant-supported full fixed prostheses (IPSPs) for the edentulous maxilla with a removable obturator offer a reasonable solution. We present herein the case of a 70-year-old Japanese man who has presented with oro-nasal defect due to surgical procedures for oral cancer. He was treated with implant-supported full fixed prostheses in a conventional two-step procedure. After prosthesis treatment, a palatal obturator was set. The patient has shown no clinical or radiological evidence of failure as of 24 months after the end of treatment. Functional evaluation of mastication and pronunciation showed dramatic improvements. For a patient with an edentulous maxilla and palatal fistula, full-arch fixed prostheses supported by a combination of axially and non-axially positioned implants and a removable oro-nasal obturator, using the anterior alveolar bone, without bone transplantation or maxillary sinus elevation, could offer an effective, minimally invasive treatment alternative.展开更多
How to improve the wear resistance of bearing surfaces, hereby achieving long life of orthopaedic joint prostheses has long been a technical challenge with much fundamental interest and social and economic impacts. Su...How to improve the wear resistance of bearing surfaces, hereby achieving long life of orthopaedic joint prostheses has long been a technical challenge with much fundamental interest and social and economic impacts. Surface engineering has been emerging as one of the most promising technologies to improve the tribological properties of biomedical materials. A current area of research within the Birmingham Surface Engineering Group has been directed at developing novel surface engineering technologies for biomedical materials towards long-life joint prostheses. Following a brief introduction, the author reports their recent progress in the surface engineering of biomedical materials particular for joint prosthesis. The potential of these innovative surface engineering technologies in enhancing the performance of oral and maxillofacial implants and surgical devices is also discussed.展开更多
文摘Orchiectomy is the recommended treatment for many testicular conditions.However,testicular prosthesis placement is not always performed for different reasons.In this study,we aimed to evaluate patients'opinions and the impact on sexual function and quality of life.This retrospective observational single-center study included patients who underwent orchiectomy between January 2014 and December 2020 at the Department of Urology,Braga's Hospital(Braga,Portugal),where testicular implants were always available and the decision to undergo the procedure was made fully independent of cost.Patients completed four questionnaires that assessed demographic data,satisfaction,self-esteem,and sexual function.Of the 96 patients who underwent orchidectomy,59 replied to the questionnaires,and of these patients,86.4%decided to undergo silicone-based testicular prostheses implantation.The remaining 13.6%refused the implant based on concerns about complications(37.5%),because they felt that it was unnecessary(37.5%),or because it was not offered by the doctor(25.0%).Overall,96.1%of these patients were satisfied with the implant;however,25.5%classified it as"too firm".No statistically significant differences were found in sexual function(all P>0.05).However,it can be observed that there are more patients with prostheses presenting normal sexual activity compared to patients without prostheses(74.0%vs 50.0%),and none of them reported severe erectile dysfunction(0 vs 16.7%).Regarding self-esteem,both patients with and without prostheses present very similar average scores with no statistically significant differences.The present study highlights the highest level of satisfaction among patients who received testicular prostheses.Testicular prostheses implantation is a safe procedure that does not hamper sexual function after orchiectomy.
文摘Background:Stapes prostheses play a crucial role in improving auditory performance and facilitating the patient's reintegration into social life.However,determining the ideal characteristics of a prosthesis and identifying the best commercially available option remain challenging.This study aims to compare the outcomes of two different types of prostheses:the MatriX Stapes Prosthesis and the new mAXIS Stapes Prosthesis.Methods:A prospective study was conducted on patients diagnosed with suspected otosclerosis who underwent stapedotomy,receiving either the MatriX or m AXIS prosthesis randomly during surgery.Postoperative follow-ups were conducted for at least one year.Audiometric evaluations were analyzed using statistical tests.Additionally,a systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Metaanalyses(PRISMA)statement.Results:The prospective study included 84 patients,divided into two groups(G1:MatriX,G2:mAXIS).The auditory results were satisfactory for both prostheses,demonstrating their effectiveness in improving hearing thresholds.We observed a gain for air conduction threshold of 26.2 dB vs 21.2 dB with an ABG closure of 20.7 dB vs and 21.2 dB in G1 and G2 respectively.The literature review encompassed 15studies,revealing overall positive outcomes with different prosthetic materials.Conclusions:The study revealed effective auditory improvement with both prostheses,yet no statistically significant differences in air-bone gap closure or average hearing gain.Titanium emerged as the preferred material due to its biocompatibility,lightweight nature,and stability under magnetic resonance imaging.The mAXIS prosthesis is introduced as a cost-effective alternative with favorable intraoperative features.
文摘The surgical techniques used by Austoni and Egydio in the treatment of Peyronie＇s disease are based on geometric principles. The aim of this paper is to report our multicentric experience and technical changes to Austoni＇s original technique, focusing on several tips and tricks to make this technique easy to perform, even by less experienced practitioners. We performed operations in three different Italian institutions. We implanted a small soft Virilis I~ axial prostheses （Ф 7 Fr.）, using a bovine pericardium collagen matrix patch （Hydrix） to cover the defect in the tunica albuginea. Sixty patients with a mean age of 58 years （range 44-76 years） underwent surgery between September 2005 and January 2010. After surgery, mean lengthening of the shaft was 2 cm （range 1.2-2.3 cm） with complete correction of penile recurvatum. Thirty-nine patients resumed sexual activity 60 days later, 14 after 90 days and 7 after 120 days. The international index of erectile function （IIEF） score was 15.5 before surgery and it improved to 23 at 12 and 24 months after surgery. Furthermore, the visual analogue scale （VAS） showed good results in terms of the recovery of natural sexual intercourse （over 80% of couples） and of the original length and girth of the penis. The soft implant we used takes advantage of erection that occurs spontaneously, using the residual erection of the spared cavernous tissue. The method is easy to learn and reproducible, and the use of pericardium speeds up the operation, while also covering large defects of the tunica albuginea that result from complex recurvatum.
基金Project(20080440850) supported by China Postdoctoral Science FoundationProject(ZJY0605-02) supported by the Natural Science Foundation of Heilongjiang Province, China
文摘The microstructure and properties of a series of binary Ti-Nb alloys for dental prostheses with niobium contents ranging from 5% to 20% were investigated. The experimental results indicate that the crystal structure and morphology of Ti-Nb alloys are sensitive to their niobium contents. When Nb content is 5%, the acicular α crystal grain is observed. When Nb content is 10%, the coarse equiaxed crystal grain and the fine, acicular α crystal grain are observed. When Nb content is 15%, only the α equiaxed crystal grain is observed. When the alloy contains 20%Nb, the equiaxed and dendritic α crystal grain are observed. For Ti-Nb alloys, the increase of Nb content modifies the microstructure of Ti-Nb alloys significantly and decreases their compression elastic modulus, in which Ti-20Nb alloy shows the largest compression strength and Ti-5Nb alloy shows the best plasticity. The dry wear resistance of Ti-Nb alloys against Gr15 ball was investigated on CJS111A ball-disk wear instrument. For Ti-Nb alloys, Ti-10Nb alloy shows a smallest steady friction coefficient, Ti-5Nb alloy shows the smallest wear depth and best wear resistance, and Ti-15Nb alloy shows the largest wear depth and worst wear resistance. The phenomenon of furrow cut happens and furrows form during wear tests.
文摘Spinal cord injury（SCI）is a debilitating condition that affects more than 2.5 million individuals worldwide（Thuret et al.,2006）.In addition to its devastating effects on the individual,this disease is a heavy burden to the society in terms of health care costs, which are estimated in billions of dollars annually in most developed countries （Cadotte and Fehlings, 2011）.
文摘There are some problems in the vascular prostheses, which influence the health of the patients. This paper aims to the radial compliance of three kinds of vascular prostheses and the pig＇s carotid based on the dynamic-simulated condition. The radial compliance of knitted structure vascular prostheses with crimps ranged from 2.52% to 0.94%/100 mmHg, which was superior to e-FFFE and woven prostheses＇, ranged from 0.73% to 0.31%/100 mmHg and from 0.81% to 0.22%/100 mmHg. But comparing with the radial compliance of pig＇s carotid, ranged from 7.21% to 10.04% /100 mmHg, there was a big gap between them. And also the trend of the radial compliance of vascular prostheses was different from the real pig＇s carotid. There is a lot of work left to improve the radial compliance, not only to change the vascular prostheses＇ compliance, but also to meet with the real vascular.
基金National Natural Science Foundations of China(No.51003014,No.31100682)Research Fund for the Doctoral Program of Higher Education of China(No.20100075110001)+1 种基金"111 Project"Biomedical Textile Materials Science and Technology of China(No.B07024)Fundamental Research Funds for the Central Universities of China
文摘Small diameter arterial prostheses were required to treat coronary and cerebrovascular arterial diseases. The diameters of the artificial blood vessels should match the diameters of the host arteries. Besides,the mechanical properties of the arterial prostheses should be strong enough to endure the forces in the body after implantation. In this study,silk and polyester were woven into small diameter arterial prostheses and the dimensional and mechanical properties,as well as the water permeability,were investigated. The woven samples had an inner diameter ranging from 3. 65 to 3. 94mm. The wall thickness of the samples ranged from 0. 26 to 0. 28mm. Compared with polytetrafiuoroethylene( ePTFE) commercial devices,whose probe bursting strength was measured to be 15. 64 N /mm2,the woven samples had superior strength values ranging from20. 53 to 28. 97 N /mm2. In addition,the radial compliance of the woven samples was found to lie between the ePTFE sample and the pig's carotid artery,and the water permeability of all the woven samples was less than 300 mL /( cm2·min) which indicated that these woven samples could be implanted without preclotting.
基金European Regional Development Fund(No.WND-POIG.01.03.01-00-007/08-00)
文摘The general object of research is to design new idea of the semi-biodegradable,multilayered vascular prosthesis used for the reconstruction of significantly small diameter vascular vessels( microreconstruction). The paper studies the selection of appropriate sterilization technique for resorbable tubular structures made of poly( L-lactide-co-glicolide)( PLAGA) and nonbiodegradable tubular structures made of polypropylene( PP). The designed grafts are characterized by the physical properties as well as mechanical properties according to ISO 7198 ∶ 1998 Standard.Moreover,the process of the grafts fabrication will be explained considering the stages affected the critical properties of the elaborated textile implants. The increase of PLAGA melt-electrospun tubular structures mechanical properties was observed due to the thermal stabilization use. The ethylene oxide( EO) and steam sterilization had a destructive effect on the designed PLAGA meltelectrospun tubular, fibrous structures, whereas the irradiation yielded in the changes in mechanical and physical properties on the acceptable level,taking into account the future clinical applications.
文摘In the experiment, we inserted the implants coated with TC4 fibers and particles into the bones of dogs.The histological characters of the bone ingrowth and the state of bone remodelling at interface were observed. And then the whole course of the fatigue injuries accumulation at the interface was monitored by scanning electron microscopy equipped with fatigue stage. Experiments show that the collagen fibers of bone interweave in the porosity of implants, which were strengthened by hydroxyapatite crystal. The collagen fibers were bound to the porous layer implant and the binding strength was enhanced by hydroxyapatite crystal. The remodelling state of bone in pores of implant and around the interface play a key role in determining the fatigue strength and the life span of the interface between bone and implant. Therefore, we consider that the interlocking fixation between bone and implant can be more exactly explained as binding mechanism.
文摘The aim of this work was to assess the preliminary anatomical and functional results of patients to establish prospects. Materials and method: We report here the preliminary results of a retrospective mono-centric, homogeneous and continuous series, of 21 non-cemented total hip implants, implanted from January 2011 to December 2014. The mean follow-up time was 24 months. The patients were evaluated by Harris’s hip at the last follow-up. Results: The mean age of the intervention was 30 years. In our series, we observed a male predominance (60% of cases). Clinically, the Harris score varied significantly from 52.6 ± 11.4 pre-operatively to 85.1 ± 5.1 during the last follow-up visit. Among the items in the score, pain was the parameter that showed the greatest improvement. Thigh pain was observed in only one patient operated on the two sides. At the level of radiology, the femoral implant showed great stability. Bone resorption was suspected in 14 cases (66.66%), and confirmed in 4 cases (19.04%) with excellent bone remodeling, illustrated by the Engh and Massin scores. A loosening and a prosthetic dislocation was observed in a patient (4.76%). Any heterotopic ossification was observed. Conclusion: Our study confirmed good clinical and radiological results of the non-cemented hip prosthesis series in young patients. The rates of aseptic loosening, acetabular edges or osteolysis are low and stable over time.
文摘The aim of this retrospective study was to compare the different anticoagulation regimens used in pregnant women with prosthetic heart valves. We reviewed 86 pregnancies in 57 women from 1987 to 2011. The patients were divided into two groups: group A (39 pregnancies) had oral acenocoumarol throughout pregnancy;and in group B (47 pregnancies), acenocoumarol was replaced by subcutaneous heparin during the first trimester. Both groups received heparin at the time of delivery. The valves replaced were mitral (59.65%), aortic (12.28%), or both (28.07%). 74 pregnancies (86.04%) resulted in live births, 9 (10.46%) had stillbirths, 1 (1.16%) had spontaneous abortion and 2 (2.32%) underwent therapeutic abortions. The live birth rate was higher in women on heparin (87.23%) compared with those on acenocoumarol (84.61%). No malformations appeared in the 74 newborns, except for one case of hydrocephalus. There was one maternal death due to acute mitral valvular thrombosis while on heparin in the first trimester. Hemorrhagic complications occurred in 13 patients in the postpartum period, 4 of whom required transfusion. No anticoagulant regimen can be said to be entirely safe for use during pregnancy as there is a degree of risk with each regimen. Heparin does not offer a clear advantage over oral anticoagulation in the pregnancy outcome.
文摘<span><span style="white-space:nowrap;font-family:Verdana;"><strong>Background:</strong></span><strong><span style="font-family:Verdana;"></span></strong></span><span>Perforation of the oesophagus is a serious condition. Most of them are iatrogenic and are associated with significant morbidity and mortality, especially with late diagnosis. </span><b><span style="font-family:Verdana;">Aim:</span></b><span style="font-family:Verdana;"> To prospectively analyse the results of the endoscopic management of iatrogenic perforations in oesophageal neoplasia, through the immediate insertion of a covered self-expanding prosthesis (CSES). </span><b><span style="font-family:Verdana;">Materials and Methods:</span></b><span style="font-family:Verdana;"> Between 01.01.2006 and 12.30.2016, a series of 19 consecutive patients attended the Teaching Unit of Endoscopic Surgery of the Regional de Concepción Hospital, Chile, with the diagnosis of oesophageal neoplasia confirmed by biopsy were prospectively studied. All were subjected to a prior evaluation by the oncology team and subsequently referred for endoscopic palliative management of dysphagia. The average age was 77 ± 9.3 years, 8 (42.1%) were female and 11 (57.9%) were male. In 17 patients (89.5%) the stenosis compromised the oesophagus, in 2 (10.5%) the gastro-oesophageal junction, 16 had a squamous carcinoma (84.2%) and 3 an adenocarcinoma (15.8%). </span><b><span style="font-family:Verdana;">Results: </span></b><span style="font-family:Verdana;">Perforation was diagnosed during the procedure in 18 patients (94.7%) and in 1 (5.3%) 22 hours later. Follow-up was done for a minimum of 90 days or until death. The prostheses were inserted successfully in all cases. The immediate evolution was satisfactory in 12 patients (63.2%). In the rest (36.8%), 18 complications appeared. The most frequent were retrosternal pain, subcutaneous emphysema and fever. The early evolution was satisfactory in 12/19 cases (63.2%). Complication was evidenced in 7 (36.8%), the most frequent was retrosternal pain (36.8%). Fever occurred in 3 (15.8%), pleural effusion in 3 (15.8%) and mediastinitis in 2 of these. The prosthesis was kept in situ as a definitive palliation method for neoplas</span><span><span style="font-family:Verdana;">tic dysphagia. In 10 of the 18 cases that survived more than a month, there were late complications (55.6%), none of them associated with the perforation itself. The only death (5.3%) was due to an oesophagus-pleural fistula, associated with an early prosthetic migration. Recovery of the oral intake occurred, on average, at 3.7 days. The hospital stay averaged 9.6 days. </span><b><span style="font-family:Verdana;">Conclusion: </span></b><span style="font-family:Verdana;">The use of CSES for the treatment of iatrogenic oesophageal perforations in the context of neoplasia, is a safe and effective method, with low morbidity, adequate recovery of the oral intake and prompt discharge from hospital.</span></span>
文摘The Ni-Cr-Mo alloys have been used as dental prostheses because they own a good mechanical strength, high corrosion resistance and even to be economically viable. These alloys corrosion protection against in salt solutions typical of physiological media is due to passivation phenomenon with an oxide surface layer formation, mainly chromium oxides. This protective film, subjected to a mechanical stress in a corrosive environment, can partially dissolve by releasing ions, which have deleterious effects in a human body. Fluoride ions, existing in hygiene products, change the buccal environment and their presence may enable a localized corrosion process initiation. The aim of this work has been to investigate the chemical composition influence of three alloys in corrosion resistance to: A (Ni-73% Cr-14% Mo-8.5% Be-1.8% Al-1.8%), B (Ni-61% Cr-25% Mo-10.5% Si-1.5%) and C (Ni-65% Cr-22.5% Mo-9.5%) in media containing fluorides that simulate mouthwashes solution. The study has been done in a 0.05% NaF solution, pH 6, at 37°C using electrochemical techniques. The alloy with the highest nickel and the lowest chromium content is not passive in the middle studied, showing a continuous increase in current density with the potential increasing, while the other alloys show passivation range of 600 mV and passive current density of about 10-6 A/cm2.
基金funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 746526from the National Health and Medical Research Council(RG1063046)
文摘The size of the blind population in 2015 was estimated to be approximately 36 million（Bourne et al.,2017）.According to the predictions by Bourne and co-workers,the number of the visually impaired is expected to reach nearly 100 million by 2050.
文摘Open oro-nasal defects resulting after oral tumor resection need structural and functional rehabilitation using dental prostheses. Conventional removable prostheses have usually been indicated and performed for prosthodontics. When the patient has an edentulous maxilla, the unfavorable stability of the prosthesis will cause dysfunction of mastication and pronunciation. To achieve improvement of the impaired functional situation, implant-supported full fixed prostheses (IPSPs) for the edentulous maxilla with a removable obturator offer a reasonable solution. We present herein the case of a 70-year-old Japanese man who has presented with oro-nasal defect due to surgical procedures for oral cancer. He was treated with implant-supported full fixed prostheses in a conventional two-step procedure. After prosthesis treatment, a palatal obturator was set. The patient has shown no clinical or radiological evidence of failure as of 24 months after the end of treatment. Functional evaluation of mastication and pronunciation showed dramatic improvements. For a patient with an edentulous maxilla and palatal fistula, full-arch fixed prostheses supported by a combination of axially and non-axially positioned implants and a removable oro-nasal obturator, using the anterior alveolar bone, without bone transplantation or maxillary sinus elevation, could offer an effective, minimally invasive treatment alternative.
文摘How to improve the wear resistance of bearing surfaces, hereby achieving long life of orthopaedic joint prostheses has long been a technical challenge with much fundamental interest and social and economic impacts. Surface engineering has been emerging as one of the most promising technologies to improve the tribological properties of biomedical materials. A current area of research within the Birmingham Surface Engineering Group has been directed at developing novel surface engineering technologies for biomedical materials towards long-life joint prostheses. Following a brief introduction, the author reports their recent progress in the surface engineering of biomedical materials particular for joint prosthesis. The potential of these innovative surface engineering technologies in enhancing the performance of oral and maxillofacial implants and surgical devices is also discussed.
