Ceramic Chip Research Articles

Construction of Microfluidic Chip Structure for Cell Migration Studies in Bioactive Ceramics.

Cell migration is an essential bioactive ceramics property and critical for bone induction, clinical application, and mechanism research. Standardized cell migration detection methods have many limitations, including a lack of dynamic fluid circulation and the inability to simulate cell behavior in vivo. Microfluidic chip technology, which mimics the human microenvironment and provides controlled dynamic fluid cycling, has the potential to solve these questions and generate reliable models of cell migration in vitro. In this study, a microfluidic chip is reconstructed to integrate the bioactive ceramic into the microfluidic chip structure to constitute a ceramic microbridge microfluidic chip system. Migration differences in the chip system are measured. By combining conventional detection methods with new biotechnology to analyze the causes of cell migration differences, it is found that the concentration gradients of ions and proteins adsorbed on the microbridge materials are directly related to the occurrence of cell migration behavior, which is consistent with previous reports and demonstrates the effectiveness of the microfluidic chip model. This model provides in vivo environment simulation and controllability of input and output conditions superior to standardized cell migration detection methods. The microfluidic chip system provides a new approach to studying and evaluating bioactive ceramics.

Success Rates of Immediately Loaded Implants in the Maxilla – A 10-year Follow-up Study

Abstract Introduction: To restore missing teeth in the mouth, dental implants are crucial. Total edentulism leaves the patient unable to chew, smile or communicate well, which can cause a psychological collapse in day-to-day activities. The objectives of this retrospective study were to report the 10-year success rates of patients with immediately loaded implants in the fully edentulous maxilla by measuring the bone level at the coronal/crestal aspect annually and also to determine the survival rates and complications of the full-arch prosthesis. Materials and Methods: Seventy-seven implants (Ankylos, Dentsply, Tulsa, OK, USA) were inserted and immediately loaded in 10 fully edentulous maxillae. Patients were rehabilitated with a cement-retained metal-reinforced provisional bridge of 10–12 units, and all implants were loaded on the same day of placement. At the 12-month follow-up and each year thereafter, the prostheses were removed, and a clinical evaluation of the peri-implant tissues and implant mobility was made for each implant. The age of the patients included in the study ranged between 45 and 77 years, with the average age being 61 years old. Radiographic bone levels were recorded post-loading at years 1–10 annually. Results: In the group of immediate loading with simultaneous augmentation, 19 of 47 implants had received vertical or horizontal augmentation due to insufficient ridge height or width. In the other group, none of the 30 immediately loaded implants received augmentation either before or simultaneous with implant placement. After a clinical and radiographic follow-up period of 12–130 months, none of these implants were lost, and the probing depths around the implants were within normal limits. None of the prostheses reported prostheses loosening, abutment screw loosening or abutment screw fracture. In one case, maxillary fixed full-arch cement-retained final prostheses had to be replaced due to a fracture of the prostheses framework, and in two cases had to be replaced due to extensive ceramic chipping; hence, the cumulative survival rate of the prostheses was 70% at the end of 10 years. Conclusion: These results seem to demonstrate that a maxillary fixed full-arch prosthesis that is supported by at least six to eight implants in uniform distribution, even with simultaneous grafting, allows good long-term success for immediately loaded implants.

Retrospective Cohort Evaluation of Full-Arch Zirconia Implant-Supported Fixed Prostheses.

Objective: To determine the median event-free survival and relative complication rates of monolithic and minimally layered full-arch zirconia prostheses, as well as to identify risk factors for prosthesis complications. Materials and Methods: In this retrospective cohort study, a total of 129 subjects (173 prostheses) were included in the chart review and 56 subjects (75 prostheses) participated in a clinical follow-up visit. All subjects had either single- or dual-arch monolithic or minimally layered zirconia implant-supported prostheses. Data related to patient, implant, and prosthesis factors were extracted from charts. The subgroup that presented for a clinical visit were asked to complete a satisfaction questionnaire. For this subgroup, the following clinical measures were assessed: routine intraoral examination, number of occluding units, cantilever length on each side of the prosthesis (right and left), prosthesis height, occlusal scheme, and oral hygiene methods. Periapical radiographs were obtained when the last radiographs of the patient were taken more than 12 months prior. Results: The follow-up period ranged from 12 months to 7.1 years (mean: 1.9 years). Observed complications included implant loss, peri-implantitis, mucositis, purulence, sinus tract formation, oroantral communication, implant fracture, titanium base debonding, ceramic chipping, prosthetic screw fracture or loosening, damage to opposing teeth, and clicking sounds. There was an insufficient number of complications to evaluate the effect of covariates on the risk of specific complications, such as titanium base debonding (eight events), ceramic chipping (nine events), and peri-implantitis (eight events). The unadjusted event-free median survival time was 5.8 years. The proportion of all prostheses with at least one complication was 30%. There were no observed prosthesis losses during the follow-up period. Conclusion: Monolithic and minimally layered zirconia full-arch implant-supported prostheses demonstrate an acceptable median event-free survival time. Event-free survival times were increased and the number of complications was reduced in prostheses with five to eight implants and conventional (as opposed to zygomatic) implants. There was a reduced hazard of complications with a regular recall regimen. Patient satisfaction with these prostheses was high.

Exceptional reliability of MLCCs enabled by defect‐engineered BaTiO3

AbstractIt has generally been believed that the reliability of BaTiO3‐based multilayered ceramic capacitors (MLCCs) is mainly contributed by hydroxyl (OH−), and the contribution of CO32− can be neglected. However, in this work, we demonstrated that the contributions of Ba/Ti ratio and CO32− play important roles in the delivering high reliability for BaTiO3‐based MLCCs. The structure and performance of MLCC devices and ceramic chips based on BaTiO3 powders prepared by different approaches were studied. It is found that the intracrystalline pores in ceramics or MLCCs are mainly derived from the decomposition of BaCO3 during sintering, which has been demonstrated by ceramic derived from hydrothermal method powder and its modified powders. The point defects of Ba and Ti vacancies mainly originating from nonstoichiometric Ba/Ti rather than thermally stimulated have substantial influence on the migration of grain boundary that determines the grain size and whether the pores can be annihilated from the bulk material. Particularly, the Ti vacancies have a strong pinning effect and inhibit the migration of grain boundary effectively, due to their shorter migration distance comparing to Ba vacancies. Therefore, the synergetic effect of the second phase BaCO3 and point defects leads to the differences in the structure and performance.

Implant Survival and Complication Prevalence in Complete-Arch Implant-Supported Fixed Dental Prostheses: A Retrospective Study with a Mean Follow-up of 5 Years.

Purpose: To evaluate the implant survival and the prevalence of biologic and mechanical complications in edentulous patients restored with complete-arch implant-supported fixed dental prostheses (IFDPs). Materials and Methods: Patients restored with complete-arch screw-retained IFDPs between January 2012 and December 2019 with a minimum 2-year follow-up were included. Outcome measures were cumulative survival rate (CSR) for implants and prostheses, biologic complications, and mechanical complications. A generalized estimating equation model was used to estimate potential risk factors for mechanical complications. Patient satisfaction was investigated using a standardized questionnaire. Results: A total of 44 prostheses supported by 268 implants in 30 patients were included for a mean duration of 4.8 years (range: 2 to 9 years). Eighteen of the prostheses were zirconia-ceramic (group ZC), and 26 were titanium-ceramic (group TC). The CSR for the implants and IFDPs was 99.3% (95% CI: 98.2% to 100.3%) and 92.5% (95% CI: 84.2% to 100.8%), respectively. The most common biologic complication was peri-implant mucositis (4.5%), followed by peri-implantitis (3.0%). The most common mechanical complication was ceramic chipping (45.5%), followed by crown debonding (13.6%) and framework fracture (4.5%). There was no significant difference in the prevalence of complications between groups TC and ZC (P > .050). The presence of cantilever (OR = 5.54, P = .048) and maxillary arch (OR = 5.94, P = .041) were significantly associated with mechanical complications. Patient satisfaction scores were generally high, but some continued to be bothered by speech problems (13.6%). Conclusion: Complete-arch IFDPs presented reliable clinical outcomes for edentulous patients with a high implant survival rate and a high level of patient satisfaction. However, a high incidence of mechanical complications occurred in the long term.

Exceptional dielectric and varistor properties of Sr, Zn and Sn co-doped calcium copper titanate ceramics.

Calcium copper titanate (CCTO) powders associated with the chemical formula Ca1-x Sr x Cu3-y Zn y Ti4-z Sn z O12 (where x, y, z varying from 0 to 0.1) were synthesized via a solid-state reaction route. Dense ceramics (>96% of theoretical density) were obtained by sintering these powders comprising micrometer-sized grains at appropriate temperatures. X-ray powder diffraction studies confirmed the formation of monophasic CCTO cubic phase, with no traceable secondary phases present. The lattice parameter 'a' was found to increase on increasing the dopant concentration. The microstructural studies performed on these ceramics confirmed a decrease in mean grain size (18 μm to 5 μm) with the increase in Sr, Zn and Sn doping concentrations as compared to that of undoped CCTO ceramics though they were sintered at the same temperature and duration (1100 °C/15 h). The dielectric studies (dielectric constant (ε') and the dielectric loss (D)) conducted in a wide frequency range (102-107 Hz) demonstrated an increase in ε' and a decrease in D on increasing the doping concentration. Impedance analysis (Nyquist plots) performed on these ceramics revealed a significant increase in grain boundary resistance. The highest value of grain boundary resistance (6.05 × 108 Ω) (in fact this value was 100 times higher than that of pure CCTO) was obtained for the composition corresponding to x = y = z = 0.075 and intriguingly the ceramic pertaining to this composition exhibited enhanced ε' (1.7 × 104) and lower D (0.024) at 1 kHz. Further, these co-doped CCTO ceramics exhibited substantial improvement in breakdown voltages and nonlinear coefficients (α). The temperature independent (30 -210 °C) dielectric response of these samples qualifies them to be suitable dielectric materials for the fabrication of multilayer ceramic chip capacitors.

Up to 10 years clinical performance of zirconia ceramic and metal-ceramic fixed partial dentures: A retrospective study

Statement of problemCompletely veneered zirconia ceramic (ZC) fixed partial dentures (FPDs) have been reported to have a higher incidence of ceramic chipping than the standard metal-ceramic FPDs. However, data from comparative long-term studies are sparse. PurposeThe purpose of this retrospective study was to compare the long-term survival, chipping-free survival, and success of ceramic-veneered high noble metal alloy (HN), base metal alloy (cobalt-chromium alloy) (CC), and ZC FPDs and to isolate risk factors for the incidence of failure, veneer chipping, and overall complications. Material and methodsData from 289 study participants (58.7% women; mean age, 57.97 ±11.51 years) provided with a total of 400 FPDs comprising 197 (49.3%) HN FPDs, 121 (30.3%) CC FPDs, and 82 (20.5%) ZC FPDs fabricated from presintered 3 mol% yttria-stabilized zirconia (mean time of service, 6.85 ±3.25 years) were evaluated. Of these, 278 (69.5%) FPDs were provided by dentists and 122 (30.5%) by dental students. Five- and 10-year survival, chipping-free survival, and success rates were calculated using the Kaplan–Meier method and compared with the log-rank test. Risk factors were assessed using Cox regression analysis. The study was exploratory, so all P values were considered exploratory and descriptive. ResultsThe 5- and 10-year survival rates were 94.7% and 77.8% for HN, 93.7% and 81.2% for CC, and 92.9% and 53.3% for ZC FPDs, respectively, indicating no clear difference in survival among the framework materials. The 5- and 10-year chipping-free rates were 94.1% and 82.8% for HN, 96.1% and 78.9% for CC, and 82.6% and 62.2% for ZC FPDs, respectively, indicating a difference between HN and ZC, and CC and ZC restorations. The 5- and 10-year success rates were 83.7% and 55.3% for HN, 86.5% and 51.4% for CC, and 68.9% and 30.2% for ZC FPDs, respectively, indicating a difference between HN and ZC, and CC and ZC restorations. The Cox regression model indicated framework material as an influencing risk factor for success, and this influence persisted when chipping was investigated. Compared with zirconia, the use of a metal alloy reduced the risk of chipping or the occurrence of complications by up to one-third. ConclusionsAll FPDs showed high 5-year survival rates and acceptable 10-year survival rates with no strong differences among the materials. Higher success and chipping-free rates were observed for both HN and CC restorations compared with ZC restorations. Metal frameworks had a lower risk for complications or veneer chipping than zirconia frameworks.

Study on the Shear Lag Effect

Shear lag effect increase as we move away from the section thereafter, the effects becomes predominant especially for the unsymmetric structures. The force transmission between the structure and patch occurs through bond layer, via shear mechanism, invariably causing shear lag. In the present study, an attempt is made to correlate the average shear stress in the bond layer obtained using the Bhalla & Soh model (2004) & BSC(Bhatt Saxena Chaudhary) model. In BSC model overall deformation of the bond layer is considered. It is simplified model of the complex shear lag phenomenon as with force transmission among PZT (lead zirconate titanate) patch and host structure .PZT is one of the world’s most widely used piezoelectric ceramic materials. When fired, PZT has a perovskite crystal structure, each unit of which consists of a small tetravalent metal ion in a lattice of large divalent metal ions. PZT is used to make ultrasound transducers both for loudspeakers and microphones and other sensors and actuators, as well as high –value ceramic capacitors and FRAM chips. PZT is also used in the manufacture of ceramic resonators for reference timing in electronic circuitry. PZT has a high dielectric constant, ferroelectric, piezoelectric, & pyroelectric properties. The ideal properties of PZT have made its application to transducer, sensor and actuator devices ubiquitous. Piezoelectric ceramics, when mechanically activated with pressure or vibration, have the capacity to generate electric voltages sufficient to spark across an electrode gap. Piezoelectric energy harvester has good compression performance, fatigue resistance and waterproof performance. Piezoelectric effect is the ability of certain materials to generate an electric charge in response to applied mechanical stress. The word Piezoelectric is derived from the Greek piezein , which means to squeeze or press ,& piezo , which is Greek for “push”. The main advantage of BSC model is that it does not involve solving the complex differential equations. Shear stress distribution is practically independent of excitation frequency except near pressure. BSC model can be made use of for carrying out the preliminary design in structural control related problems.

Marginal Bone Loss and Clinical Complications in Surviving Implants and Recently Placed Implants Splinted Together: A Retrospective Study.

The objective of this study was to compare marginal bone loss (MBL) and clinical complications between surviving implants (SIs) and recently placed implants (RIs) splinted together to support a fixed partial restoration (FPR). This retrospective study employed the medical records of patients treated with implant-supported FPRs in the Maccabi-Dent Dental Clinic. Patients were included if they were over the age of 18 years, were treated with RIs adjacent to existing SIs that had previously supported FPRs for more than 1 year, and the RIs and SIs were splinted to support new FPRs. Patients who did not receive annual follow-up or whose records had nondiagnostic radiographs or lacked sufficient restorative data were excluded. MBL was assessed at the last available radiograph and compared to one taken 1 year after loading the splinted RIs and SIs together. Clinical complication data were gathered from patient records. The medical records of 1,907 patients treated with a total of 7,306 implants were examined. Data from 187 implants were extracted from 46 patient records that met the inclusion criteria, with 96 RIs and 91 SIs supporting 56 FPRs. Mean followup was 39 ± 17.5 months. During the follow-up, two implants failed. The overall survival rate was 98.94% (98.96% in RIs and 98.91% in SIs), and the mean MBL in all implants was 0.41 ± 0.58 mm (0.4 ± 0.53 mm in RIs and 0.42 ± 0.45 mm in SIs). Peri-implantitis was reported in eight (4.3%) implants (four RIs and four SIs), screw loosening was reported in nine (4.8%) implants (three RIs and six SIs), ceramic chipping was reported in three (5.3%) restorations supported by four RIs and six SIs, and decementation was reported in one (1.8%) restoration supported by one RI and one SI. There was no statistically significant difference in survival rate, MBL, peri-implantitis, or screw loosening between RIs and SIs. There was no statistically significant difference in MBL or clinical complications between RIs and SIs. Splinting RIs and SIs for new prosthetic restoration support is a reasonable treatment choice with a high implant survival rate, low incidence of complications, and acceptable MBL.

Immediate Functional Loading with Full-Arch Fixed Implant-Retained Rehabilitation in Periodontal Patients: Clinical Study.

(1) Background. The immediate functional loading of implants is a clinical procedure used for treating periodontal edentulous patients. This clinical study aimed to evaluate the clinical outcomes of the immediate functional loading of implants with fully fixed rehabilitations in compromised periodontal patients. (2) Methods. Three hundred and five implants IPX screw implants were placed in 27 periodontal patients using an immediate functional loading protocol with fixed rehabilitations. All patients had a previous history of periodontitis, four patients (14.8%) were smokers and seven patients (25.9%) suffered from chronic medical conditions. (3) Results. Implant and prosthetic clinical findings were evaluated during a mean period of 41.3 ± 19.6 months. No implants were lost during the clinical follow-up. The cumulative survival rate for all implants was 100%. Regarding the prostheses designed, a total of 54 fixed prostheses were placed in the 27 patients immediately after the surgery. Forty-four hybrid fixed prostheses (81.5%) and 10 fixed rehabilitations (18.5%) were placed in the patients. The mean marginal bone loss was 1.51 ± 1.16 mm, ranging from 0 to 3.5 mm during the follow-up evaluation. Thirty-one implants (10.2%) in 10 patients (37%) were associated with peri-implantitis. Five patients (18.5%) showed some kind of technical complications (loss/fracture of the prosthetic screw, acrylic resin fracture, ceramic chipping). (4) Conclusions. The clinical outcomes of this study demonstrate that fixed rehabilitation by immediate functional loading of implants is considered a predictable procedure.

(Digital Presentation) A Disposable Chip Sensor for the Detection of Vancomycin: Studying the Long-Term Stability

Vancomycin is one of the most important anti-bacterial drugs for the treatment of MRSA infection. Continuous monitoring is commonly recommended as it has a low therapeutic window, which is often limited by the equipment cost, and the technical skills required for modern TDM techniques such as HP-LCs and immunoassays. As a result, a cost-effective and quick detection solution for Vancomycin TDM is critical. We have already reported a successful vancomycin sensor on a ceramic base, a paper base, and a PET (polyethylene terephthalate) base, in our previous works 1,2. However, the long-term stability of the sensor for the clinical trial is very important. Therefore, this study focused on the improvement of the stability of the sensor.The PET chip is composed of a PET base on which the silver wiring was printed using an inkjet printer. It contains two holes for electrodes with a 2.0 mm diameter for the counter electrode and a 1.0 mm diameter for the working electrode. The chip also comprises a circular reservoir of diameter 8 mm. VCM imprinted poly(methylene bisacrylamide-co-methacrylic acid-co-Allylaminocarboxypropyonic-3-ferrocene) was grafted on graphite particle surface by a procedure similar to our previous work. This grafted graphite was mixed with a) silicon oil (MIPsi ), and b) paraffin oil (MIPpff ) to make a paste to use as the sensing material. The viscosity of both the oils was the same. We performed the chronoamperometric analysis with a VCM sample solution (0-60 µgmL-1, in phosphate buffer) filled in the sample reservoir.The chronoamperometric analysis time was 15 seconds for each sample. Current obtained at the 10th second was recorded to obtain the calibration curve. The change in current at 10s demonstrated strong linearity with the VCM concentration in both MIPsi and MIPpff , indicating good linearity with the change in current at 10s. Furthermore, this result was obtained using a "single-use" chip, which implies that each concentration was measured using a separate chip. MIPsi and MIPpff were both sensitive to vancomycin. However, when the sensor was packed and kept for 3 days, the MIPsi sensor lost its sensitivity completely. Sensor with the working electrode made of MIPpff, however, retained their sensitivity. MIPpff was further packed and kept for 10 days to have a deeper insight into the effect of binder oil on the long-term stability of the sensor and the sensor was still found to be sensitive. From the results of this study, it can be concluded that a stable sensor that can sensitively detect vancomycin can be made using paraffin oil as the binder oil. References Aaryashree, A., Takeda, Y., Yoshimi, Y., Hatano, A. & Kida, M. A Disposable Vancomycin Sensor Using Molecularly Imprinted Carbon Paste on a Ceramic Chip. in ECS Meeting s vols MA2020-02 3332–3332 (2020).Aaryashree et al. A “Single-Use” Ceramic-Based Electrochemical Sensor Chip Using Molecularly Imprinted Carbon Paste Electrode. Sensors 20, 5847 (2020).

Single-crown restorations in premolar–molar regions: short (≤ 6.5) vs longer implants: retrospective cohort study

PurposeTo compare the survival, changes in marginal bone level and prosthetic complications rate of short (≤ 6.5 mm) and longer implants (≥ 7.5) supporting a single-crown restoration in the maxillary/mandibular premolar or molar region.MethodsThis cohort study was conducted following the STROBE statement recommendations for observational studies. Clinical outcomes of 88 short implants in 78 patients and 88 long implants in 88 patients were examined. All the implants had been placed by the same surgeon and restored following the same prosthetic concept; using a transepithelial abutment (intermediate abutment) and a screw retained restoration.ResultsAll the implants were in function after the follow-up period since insertion (median: 31 months; range 11 to 84 for SiG vs median: 35 months; range: 6–117 for CG; p = 0.139). No statistical differences (p = 0.342) were observed related to prosthetic complications (screw loosening 2/88 vs 5/88 CG, ceramic chipping 1/88 vs 0/88, temporary crown resin chipping 1/88 vs 0/88 for SiG and CG, respectively) or related to marginal bone level (Mesial or Distal MBL ≥ 2 mm in 1/88 implants for SiG vs 3/88 for CG; p = 0.312).ConclusionsWithin the limitations of this study, no survival differences have been observed between short implants and longer implants in single-crown restorations in posterior maxilla/mandible.

Wearable grain silo working environment sensing and safety alarm system

<p>A set of wearable granary working environment sensing and security alarm system is developed to ensure the safety of granary staff. The gas sensor, piezoelectric ceramic chip, infrared transmitting and receiving tube and photosensitive resistance are used as the core components of each circuit module to collect the gas concentration signal, human respiration intensity signal, pulse intensity signal and light signal in the granary. AD0809 module chip is used to convert analog data into digital data and send it to MCU for information processing to make alarm judgment. At the same time, PTR2000 module is used to transmit the sensor data to the upper computer. The upper computer determines whether to alarm through data comparison, and transmits the alarm signal to the mobile phone through Wi-Fi in real time. Each module cooperates with each other, information real-time transmission to complete the detection of granary environment and danger alarm. The test results show that the system can meet the safety operation requirements of large and medium-sized state-owned grain depot.</p>

Occlusion on a Single Implant-Supported Crown: Any differences?

Dental implants react biomechanically to the occlusal forces placed on them, in a different fashion to teeth, which can make them prone to overloading. This can lead to a range of mechanical problems, including screw loosening, ceramic chipping, and fracture of components, but it can also be associated with biological complications such as later peri-implantitis. Appropriate occlusal loading is essential to maintain long-term stability of implant-retained restorations. Clinicians must be aware that, to varying extents, complications do occur with single implant-retained crowns. Dental implants are not a panacea; it is unwise to describe implants as being either perfect or permanent because they are neither. Patients need to understand, well in advance of having implant-based treatment, that the placement of titanium in their jaw(s) will not stop their parafunctional habits, such as clenching or bruxism. Insertion of titanium screws of various types and roughness will certainly not alter their susceptibility to their own plaque-induced inflammatory periodontal disease which is often manifested as peri-mucositis, or later as peri-implantitis in susceptible patients. Based on the available data, this paper provides recommendations to optimise clinical outcomes for single implant-supported crowns. When designing implants, the focus should be on achieving axial forces during chewing. It is wise to minimise horizontal and non-axial loads to avoid potential damage to ceramic or other prosthetic components, and to minimise the risks of bone resorption occurring around the implants themselves at a later stage. Occlusal relationships of implant-retained restorations should be carefully evaluated on a regular basis. Accurate occlusal records of the starting point are extremely helpful in assessing the ongoing status of any restorations.

Enzyme-modulated photothermal immunoassay of chloramphenicol residues in milk and egg using a self-calibrated thermal imager

Highly sensitive and accurate detection of chloramphenicol is of paramount importance for food safety. Herein, an enzyme-modulated photothermal immunosensor that uses a self-calibrated thermal imaging system (SCTIS) as signal read-out was developed for detecting chloramphenicol. In this immunosensor, alkaline phosphatase was used as a modulator of the photothermal conversion. It could hydrolyze the substrate into ascorbic acid, thereby reducing oxidized 3,3′,5,5′-tetramethylbenzidine, which exhibited a near-infrared laser-driven photothermal effect. For precise temperature measurement, the SCTIS was designed by using the temperature compensation of a ceramic chip to enable real-time self-calibration of the temperature. This SCTIS-based immunosensor could detect chloramphenicol with a LOD of 9 pg/mL in 2 h, and relative standard derivations from 3.95% to 13.58%. The average recoveries in milk and egg samples ranged from 76% to 114%. This versatile sensing strategy can detect various targets by altering recognition elements, thus has wide applicability in food safety testing and monitoring.

Investigation on the magnetic properties and microstructures of FeCoAlN thin films deposited by doping AlN ceramic chips

Investigation on the magnetic properties and microstructures of FeCoAlN thin films deposited by doping AlN ceramic chips

Longevity and failure mode of posterior ceramic crowns and fixed partial denture

The purpose of this review is to analyse the longevity of posterior all-ceramic crowns and fixed partial dentures; in addition to determine the failure mode. It seeks to assess the risk factors that should be considered with posterior all-ceramic restorations. The review of literature revealed an acceptable longevity for posterior all-ceramic restorations in a 5-year follow up period. This accompanies their aesthetic outcome especially with improving of mechanical properties of glass ceramic by adding reinforcement crystalline phases or using core. The loss of vitality and secondary caries were the common biological complications while ceramic fracture and chipping were the most frequent mechanical complications. Also, the para-functional activity and using implant as an abutment increase the risk of failure especially on posterior teeth.

Application of magnetic immunofluorescence assay based on microfluidic technology to detection of Epstein-Barr virus

EB病毒(Epstein-Barr virus, EBV)的早期诊断能够降低患者发生重大疾病的风险。临床上常用的EBV抗体的检测方法存在耗时长、试剂消耗大和效率低等缺点。相比于传统的检测方法,微流控(microfluidics)技术具有高通量、试剂消耗少,污染少和自动化程度高等优点,磁免疫荧光技术具有检测效率高、信号强等优点,将两者的优势结合,能够弥补传统方法的不足。鉴于此,采用聚甲基丙烯酸甲酯(PMMA)作为芯片原材料,经过激光切割及真空热压加工工艺能够快速获得芯片。将包被抗原的磁珠及包被抗人抗体的荧光微球经过冷冻干燥工艺快速冻干成小球并嵌入芯片内,经过孵育和清洗后,进行检测。通过图像分析快速得到检测结果。通过精密度、特异性、剂量-反应曲线及检出限测试,进行性能验证。通过与化学发光免疫分析法(CLIA)检测的临床样本比对,进行方法学与临床应用评价。结果显示相对标准偏差(RSD)均小于10%。与多种常见的病原体抗体均无交叉反应。EB病毒衣壳抗原(Epstein-Barr viral capsid antigen, EB VCA)IgG项目的检出限为1.92 U/mL,线性范围为1.92~200 U/mL,阳性符合率为95.77%(68/71),阴性符合率为86%(43/50); EB VCA IgA项目的检出限为2.79 U/mL,线性范围为2.79~200 U/mL,阳性符合率为92%(46/50),阴性符合率为92.96%(66/71); EB病毒核心抗原1(Epstein-Barr nuclear antigen 1, EB NA1)IgG项目的检出限为3.13 U/mL,线性范围为3.13~200 U/mL,阳性符合率为92.96%(66/71),阴性符合率为92%(46/50); EB NA1 IgA项目的检出限为1.53 U/mL,线性范围为1.53~200 U/mL,阳性符合率为90%(45/50),阴性符合率为91.55%(65/71)。4个项目能在20 min内快速完成检测,且与临床上使用CLIA方法测试的结果具有良好的相关性,可以为临床提供一种快速、灵敏、简便、自动化程度高和易于基层推广的检测方法。

Thermal fatigue reliability improvement of leadless ceramic chip carrier solder joints

In order to improve the thermal fatigue reliability of LCCC (Leadless Ceramic Chip Carrier) solder joints, the assembly process and failure mechanism of LCCC devices are analyzed. It is concluded that the solder joints height is the main factor to improve its thermal fatigue reliability. Reliability qualification tests are performed to contrast the improvement effect of several methods. The Sn10Pb90 column mounting specimen can greatly improve the fatigue reliability and can adapt to most environmental requirements. Some significant conclusions are drawn by comparing the tests results of different specimens. The method can also be used for the other package types to improve the reliability.

Structural evolution of organic-inorganic hybrid crystals for high colour-rendering white LEDs.

Luminescent crystals with high efficiency have huge potential in applications for white light-emitting diodes (LEDs). Herein, organic-inorganic hybrid crystals doped with Mn4+, [N(CH3)4]2XF6:Mn4+ (X = Si, Ge, and Ti), were grown under mild conditions. Their crystal structural evolution was confirmed by single-crystal X-ray diffraction at different temperatures. These crystals exhibit intense red emission with a high external quantum efficiency (73.0% for [N(CH3)4]2TiF6:Mn4+) and good thermal stability. The warm white LEDs were fabricated by combining these red-emitting phosphors with a YAG:Ce3+ ceramic chip. As-grown crystals can significantly optimize the performances of white LEDs (colour rendering index up to 95). Hence, this work provides a new strategy to explore Mn4+-activated organic-inorganic hybrid materials for white LEDs.