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1.
Urol Oncol ; 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38600002

RESUMO

OBJECTIVE: Renal cell carcinoma (RCC) is a common malignant tumor with a high incidence in males and the elderly, and clear cell RCC (ccRCC) is the most common RCC subtype. ccRCC is highly metastatic with a poor prognosis. Therefore, it is crucial to obtain a detailed understanding of the molecular mechanism of ccRCC and to identify suitable biomarkers to realize early diagnosis and improve prognosis. METHODS: We analyzed data from the Cancer Genome Atlas, investigated the overall differential expression of CD276 in ccRCC, and evaluated the influence of CD276 on patient survival and prognosis. We also performed gene set enrichment analysis (GSEA) and pathway enrichment analysis and investigated cell infiltration and drug responsiveness to further assess the regulatory effect of CD276 on ccRCC. Furthermore, we verified CD276 expression in RCC cell lines and control cell lines. RESULTS: The CD276 expression level in ccRCC samples was higher than that in corresponding samples adjacent to the tumors. Moreover, high CD276 expression levels were positively correlated with poor prognosis in patients with RCC. GSEA revealed that CD276 was significantly involved in immune-related pathways, and the level of CD276 expression was confirmed as associated with immune cell infiltration to some extent. Notably, some drugs were predicted to act on CD276, and this was confirmed by molecular docking. Furthermore, high levels of CD276 expression in RCC cell lines were verified. CONCLUSION: CD276 expression was significantly increased in ccRCC tissues and cells and positively correlated with patient prognosis. CD276 is a potential prognostic biomarker of ccRCC. Overall, this study provides a potential therapeutic strategy for ccRCC.

2.
Sensors (Basel) ; 24(6)2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38544196

RESUMO

The measurement of bladder volume is crucial for the diagnosis and treatment of urinary system diseases. Ultrasound imaging, with its non-invasive, radiation-free, and repeatable scanning capabilities, has become the preferred method for measuring residual urine volume. Nevertheless, it still faces some challenges, including complex imaging methods leading to longer measurement times and lower spatial resolution. Here, we propose a novel three-point localization method that does not require ultrasound imaging to calculate bladder volume. A corresponding triple-element ultrasound probe has been designed based on this method, enabling the ultrasound probe to transmit and receive ultrasound waves in three directions. Furthermore, we utilize the Hilbert Transform algorithm to extract the envelope of the ultrasound signal to enhance the efficiency of bladder volume measurements. The experiment indicates that bladder volume estimation can be completed within 5 s, with a relative error rate of less than 15%. These results demonstrate that this novel three-point localization method offers an effective approach for bladder volume measurement in patients with urological conditions.


Assuntos
Algoritmos , Bexiga Urinária , Humanos , Bexiga Urinária/diagnóstico por imagem , Ultrassonografia/métodos
3.
Phys Med Biol ; 69(6)2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38373347

RESUMO

Objective.Accurate delineation of organs-at-risk (OARs) is a critical step in radiotherapy. The deep learning generated segmentations usually need to be reviewed and corrected by oncologists manually, which is time-consuming and operator-dependent. Therefore, an automated quality assurance (QA) and adaptive optimization correction strategy was proposed to identify and optimize 'incorrect' auto-segmentations.Approach.A total of 586 CT images and labels from nine institutions were used. The OARs included the brainstem, parotid, and mandible. The deep learning generated contours were compared with the manual ground truth delineations. In this study, we proposed a novel contour quality assurance and adaptive optimization (CQA-AO) strategy, which consists of the following three main components: (1) the contour QA module classified the deep learning generated contours as either accepted or unaccepted; (2) the unacceptable contour categories analysis module provided the potential error reasons (five unacceptable category) and locations (attention heatmaps); (3) the adaptive correction of unacceptable contours module integrate vision-language representations and utilize convex optimization algorithms to achieve adaptive correction of 'incorrect' contours.Main results. In the contour QA tasks, the sensitivity (accuracy, precision) of CQA-AO strategy reached 0.940 (0.945, 0.948), 0.962 (0.937, 0.913), and 0.967 (0.962, 0.957) for brainstem, parotid and mandible, respectively. The unacceptable contour category analysis, the(FI,AccI,Fmicro,Fmacro)of CQA-AO strategy reached (0.901, 0.763, 0.862, 0.822), (0.855, 0.737, 0.837, 0.784), and (0.907, 0.762, 0.858, 0.821) for brainstem, parotid and mandible, respectively. After adaptive optimization correction, the DSC values of brainstem, parotid and mandible have been improved by 9.4%, 25.9%, and 13.5%, and Hausdorff distance values decreased by 62%, 70.6%, and 81.6%, respectively.Significance. The proposed CQA-AO strategy, which combines QA of contour and adaptive optimization correction for OARs contouring, demonstrated superior performance compare to conventional methods. This method can be implemented in the clinical contouring procedures and improve the efficiency of delineating and reviewing workflow.


Assuntos
Algoritmos , Tomografia Computadorizada por Raios X , Planejamento da Radioterapia Assistida por Computador/métodos , Órgãos em Risco , Processamento de Imagem Assistida por Computador/métodos
4.
Nanomicro Lett ; 16(1): 122, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38372850

RESUMO

Compared with traditional piezoelectric ultrasonic devices, optoacoustic devices have unique advantages such as a simple preparation process, anti-electromagnetic interference, and wireless long-distance power supply. However, current optoacoustic devices remain limited due to a low damage threshold and energy conversion efficiency, which seriously hinder their widespread applications. In this study, using a self-healing polydimethylsiloxane (PDMS, Fe-Hpdca-PDMS) and carbon nanotube composite, a flexible optoacoustic patch is developed, which possesses the self-healing capability at room temperature, and can even recover from damage induced by cutting or laser irradiation. Moreover, this patch can generate high-intensity ultrasound (> 25 MPa) without the focusing structure. The laser damage threshold is greater than 183.44 mJ cm-2, and the optoacoustic energy conversion efficiency reaches a major achievement at 10.66 × 10-3, compared with other carbon-based nanomaterials and PDMS composites. This patch is also been successfully examined in the application of acoustic flow, thrombolysis, and wireless energy harvesting. All findings in this study provides new insight into designing and fabricating of novel ultrasound devices for biomedical applications.

5.
Orthop Surg ; 16(3): 687-699, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38316415

RESUMO

PURPOSE: Multilevel cervical spondylotic myelopathy poses significant challenges in selecting optimal surgical approaches, warranting a comprehensive understanding of their biomechanical impacts. Given the lack of consensus regarding the most effective technique, this study aims to fill this critical knowledge gap by rigorously assessing and comparing the biomechanical properties of three distinct surgical interventions, including anterior controllable antedisplacement and fusion (ACAF), anterior cervical corpectomy decompression and fusion (ACCF), and anterior cervical discectomy and fusion (ACDF). The study offers pivotal insights to enhance treatment precision and patient outcomes. METHODS: The construction of the cervical spine model involved a detailed process using CT data, specialized software (Mimics, Geomagic Studio, and Hypermesh) and material properties obtained from prior studies. Surgical instruments were modeled (titanium mesh, anterior cervical plate, interbody cage, and self-tapping screws) to simulate three surgical approaches: ACAF, ACCF, and ACDF, each with specific procedures replicating clinical protocols. A 75-N follower load with 2 Nm was applied to simulate biomechanical effects. RESULTS: The range of motion decreased more after surgery for ACAF and ACDF than for ACCF, especially in flexion and lateral bending. ACCF have higher stress peaks in the fixation system than those of ACAF and ACDF, especially in flexion. The maximum von Mises stresses of the bone-screw interfaces at C3 of ACCF were higher than those of ACAF and ACDF. The maximum von Mises stresses of the bone-screw interfaces at C6 of ACDF were much higher than those of ACAF and ACCF. The maximum von Mises stresses of the grafts of ACCF and ACAF were much higher than those of ACDF. The maximum von Mises stresses of the endplate of ACCF were much higher than those of ACAF and ACDF. CONCLUSION: The ACAF and ACDF models demonstrated superior cervical reconstruction stability over the ACCF model. ACAF exhibited lower risks of internal fixation failure and cage subsidence compared to ACCF, making it a promising approach. However, while ACAF revealed improved stability over ACCF, higher rates of subsidence and internal fixation failure persisted compared to ACDF, suggesting the need for further exploration of ACAF's long-term efficacy and potential improvements in clinical outcomes.


Assuntos
Doenças da Medula Espinal , Fusão Vertebral , Espondilose , Humanos , Análise de Elementos Finitos , Fusão Vertebral/métodos , Discotomia/métodos , Doenças da Medula Espinal/cirurgia , Vértebras Cervicais/cirurgia , Descompressão , Resultado do Tratamento , Espondilose/cirurgia , Estudos Retrospectivos
6.
Ultrasonics ; : 107107, 2023 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-37739919

RESUMO

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/policies/article-withdrawal.

7.
Front Oncol ; 13: 1167177, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37064085

RESUMO

Objective: To evaluate the safety and clinical effect of tubular esophagogastric anastomosis in laparoscopic radical proximal gastrectomy. Methods: A retrospective analysis was conducted involving 191 patients who underwent laparoscopic radical proximal gastrectomy in the Department of Gastrointestinal Surgery, Qilu Hospital of Shandong University from January 2017 to October 2020. Patients were divided into tubular esophagogastric anastomosis group (TG group) and traditional esophagogastric anastomosis group (EG group) according to the digestive tract reconstruction. Their intraoperative conditions, perioperative recovery and postoperative follow-up were compared. Patients were also divided into indocyanine green group and non-indocyanine green group according to whether or not indocyanine green tracer technology was used during the operation. Their intraoperative condition and perioperative recovery were compared and analyzed after propensity score matching. Results: The operation was successfully completed in all patients. Compared with the EG group, the TG group had less volume of gastric tube drainage, shorter gastric tube drainage time and proton pump inhibitors application time, and lower reuse rate of proton pump inhibitors. However, the TG group had a higher anastomotic stenosis at three months after surgery, as measured using anastomotic width and dysphagia score. Nevertheless, the incidence of reflux esophagitis and postoperative quality of life score in the TG group were lower compared with the EG group at 1st and 2nd year after surgery. In the indocyanine green analysis, the indocyanine green group had significantly shorter total operation time and lymph node dissection time and less intraoperative blood loss compared with the non-indocyanine green group. However, compared with the non-indocyanine green group, more postoperative lymph nodes were obtained in the indocyanine green group. Conclusion: Laparoscopic radical proximal gastrectomy is safe and effective treatment option for upper gastric cancer. Tubular esophagogastric anastomosis has more advantages in restoring postoperative gastrointestinal function and reducing reflux, but it has a higher incidence of postoperative anastomotic stenosis compared with traditional esophagogastrostomy. The application of indocyanine green tracer technique in laparoscopic radical proximal gastrectomy has positive significance.

8.
Clin Lab ; 68(7)2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35975526

RESUMO

BACKGROUND: The goal was to simply and efficiently predict the indicators of disease severity in knee osteoarthritis (KOA) patients. METHODS: One hundred eighty-four patients with KOA and 126 healthy subjects were included. WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) was used as a reference index for disease severity in KOA patients, in which WOMAC < 80 was classified as mild and WOMAC ≥ 80 as moderate and severe. Blood routine parameters of the KOA and the healthy groups were analyzed by the Mann Whitney U test. Receiver operating characteristic curves were used to analyze the sensitivity and specificity of mean corpuscular hemoglobin and platelet distribution width ratio (MPR) and monocyte and hemoglobin ratio (MHR) indicators. The correlation between MPR and MHR and disease severity of KOA was determined by bivariate regression analysis. Independent predictors of disease severity in patients with KOA were assessed by multivariate regression analysis. RESULTS: MPR, MHR, and WOMAC were significantly higher in the KOA group. The ROC curve indicated that the cutoff values of MPR and MHR were 2.09 and 0.0030, respectively, with sensitivity of 86.4% and 68.5% and specificity of 99.2% and 79.4%. Bivariate regression analysis found that MPR was better correlated with disease severity than MHR. The results of multivariate regression analysis demonstrated that the MPR values of moderate and severe patients were more than 19 times that of mild patients, and the OR values were 21.695 and 19.558, respectively. CONCLUSIONS: MPR and MHR demonstrated a good correlation with disease severity in patients with KOA. MPR is a potential independent predictor of disease severity in patients with KOA.


Assuntos
Osteoartrite do Joelho , Índices de Eritrócitos , Testes Hematológicos , Humanos , Osteoartrite do Joelho/diagnóstico , Índice de Gravidade de Doença , Estatísticas não Paramétricas
9.
Am J Transl Res ; 14(5): 3448-3455, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35702122

RESUMO

Percutaneous vertebroplasty (PVP) via the unilateral posterosuperior approach has achieved good clinical results for the treatment of osteoporotic vertebral compression fractures. This study compared the biomechanical performance of a single vertebral body after PVP by the unilateral posterosuperior, unipedicular, and bipedicular approaches. Twenty-one vertebral bodies from the osteoporotic spine segments (T11-L1) of seven older female cadavers were randomly assigned to the unipedicular (group A), bipedicular (group B), or unilateral posterosuperior approach group (group C). After constructing the fracture compression model, PVP was performed by the different approaches. CT scans showed symmetrical, evenly distributed bone cement in groups B and C and unilaterally distributed cement in group A. The recovery rates of the anterior vertebral body height in groups B and C were significantly higher than those in group A after PVP (P<0.05). The left curvature elastic moduli after PVP were significantly higher in group A than in groups B and C; however, the right curvature moduli in group A were lower than in the other groups (P<0.05). The flexion, extension, and vertical compression elastic moduli were lowest in group B (P<0.05). After PVP, failure strength and stiffness in groups B and C were comparable (P>0.05) and higher than those in group A (P<0.05). PVP through the unilateral posterosuperior approach was superior to the unipedicular approach and comparable to the bipedicular approach based on the biomechanical performance of a single vertebral body. Due to its safety, simplicity, and efficacy, the unilateral posterosuperior approach is recommended for clinical application.

10.
Sci Adv ; 8(15): eabk0159, 2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-35427156

RESUMO

Supplying wireless power is a challenging technical problem of great importance for implantable biomedical devices. Here, we introduce a novel implantable piezoelectric ultrasound energy-harvesting device based on Sm-doped Pb(Mg1/3Nb2/3)O3-PbTiO3 (Sm-PMN-PT) single crystal. The output power density of this device can reach up to 1.1 W/cm2 in vitro, which is 18 times higher than the previous record (60 mW/cm2). After being implanted in the rat brain, under 1-MHz ultrasound with a safe intensity of 212 mW/cm2, the as-developed device can produce an instantaneous effective output power of 280 µW, which can immediately activate the periaqueductal gray brain area. The rat electrophysiological experiments under anesthesia and behavioral experiments demonstrate that our wireless-powered device is well qualified for deep brain stimulation and analgesia applications. These encouraging results provide new insights into the development of implantable devices in the future.

11.
IEEE Trans Biomed Eng ; 69(10): 3155-3162, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35324431

RESUMO

OBJECTIVE: Transcranial focused ultrasound (tFUS) is regarded as a promising non-invasive stimulation tool for modulating brain circuits. The aim of this study is to explore the feasibility of tFUS stimulation for analgesia applications. METHODS: 50 µl of 3% formalin solution was injected into the rat's left hindpaw to build a pain model, and then the local field potential (LFP) activities of the dorsal horn were tracked after a recording electrode was placed in the spinal cord. Rats were randomly divided into two groups: control group and tFUS group. At the 30th minute after formalin injection, tFUS (US-650 kHz, PD = 1 ms, PRF = 100 Hz, 691 mW/cm2) was conducted to stimulate the periaqueductal gray (PAG) for 5 minutes (on 5 s and off 5 s) in the tFUS group, but there was no treatment in the control group. In addition, the analgesia mechanism (LFP recording from the PAG) and safety assessment (histology analysis) were carried out. RESULTS: The tFUS stimulation of the PAG can suppress effectively the nociceptive activity generated by formalin. The findings of the underlying mechanism exploration indicated that the tFUS stimulation was able to activate the PAG directly without causing notable temperature change and tissue injury. CONCLUSION: The results illustrated that the tFUS stimulation of the PAG can achieve the effect of analgesia. SIGNIFICANCE: This work provides new insights into the development of non-invasive analgesic technology in the future.


Assuntos
Analgesia , Substância Cinzenta Periaquedutal , Animais , Formaldeído/farmacologia , Dor/tratamento farmacológico , Substância Cinzenta Periaquedutal/fisiologia , Ratos , Medula Espinal
12.
Medicine (Baltimore) ; 101(8): e28986, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35212311

RESUMO

INTRODUCTION: The CXC chemokines are unique cytokines that play a vital role in the progression of many cancers. Association between chemokine (C-X-C motif) receptor 2 (IL8RB) C1208T mutation and cancer risk remains incomprehensive. METHODS: We therefore utilized odds ratios and in silico analysis to explore the relationship of IL8RB polymorphism on risk to cancer. Furthermore, we adopted gene set enrichment analysis to investigate the IL8RB expression in prostate adenocarcinoma. RESULTS: A total of 14 case-control studies combined with 5299 cases and 6899 controls were included in our analysis. We revealed that individuals carrying TT genotype had an 14% increased cancer risk compared with those with TC + colon cancer (CC) genotype (odds ratio [OR] = 1.14, 95% CI = 1.05-1.25, P = .003, I2 = 35.6). Stratification analysis by race showed that East Asians with TT + TC genotype may have a 25% decreased cancer risk compared with control. Stratification analysis by cancer type revealed that individuals with TT genotype were associated with elevated risk of urinary cancer than control. The expression of IL8RB was attenuated in prostate adenocarcinoma. CONCLUSIONS: IL8RB C1208T may be correlated with the risk of cancer, especially prostate adenocarcinoma.


Assuntos
Adenocarcinoma/genética , Neoplasias da Próstata/genética , Receptores de Interleucina-8B/genética , Estudos de Casos e Controles , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Mutação/genética , Polimorfismo Genético , Polimorfismo de Nucleotídeo Único , Fatores de Risco
13.
Orthop Surg ; 14(2): 331-340, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34935286

RESUMO

OBJECTIVE: To achieve the anatomical evaluation of spinal nerve and cervical intervertebral foramina in anterior controllable antedisplacement and fusion (ACAF) surgery, a novel surgical technique with the wider decompression, through a cadaveric and radiologic study. METHODS: Radiographic data of consecutive 47 patients (21 by ACAF and 26 by anterior cervical corpectomy and fusion [ACCF]) who have accepted surgery for treatment of cervical ossification of the posterior longitudinal ligament(OPLL) and stenosis from March 2017 to March 2018 were retrospectively reviewed and compared between an ACAF group and ACCF group. Three postoperative radiographic parameters were evaluated: the decompression width and the satisfaction rate of decompression at the entrance zone of intervertebral foramina on computed tomography (CT), and the transverse diameter of spinal cord in the decompression levels on magnetic resonance imaging (MRI). In the anatomic study, three fresh cadaveric spines (death within 3 months) undergoing ACAF surgery were also studied. Four anatomic parameters were evaluated: the width of groove, the distance between the bilateral origins of ventral rootlets, the length of ventral rootlet from their origin to the intervertebral foramina, the descending angle of ventral rootlet. RESULTS: The groove created in ACAF surgery included the bilateral origins of ventral rootlets. The rootlets tended to be vertical from the rostral to the caudal direction as their takeoff points from the central thecal sac became higher and farther away from their corresponding intervertebral foramina gradually. No differences were identified between left and right in terms of the length of ventral rootlet from the origin to the intervertebral foramina and the descending angle of ventral rootlet. The decompression width was significantly greater in ACAF group (19.2 ± 1.2 vs 14.7 ± 1.2, 21.3 ± 2.2 vs 15.4 ± 0.9, 21.5 ± 2.1 vs 15.7 ± 1.0, 21.9 ± 1.6 vs 15.9 ± 0.8, from C3 to C6 ). The satisfactory rate of decompression at the entrance zone of intervertebral foramina tended to be better in the left side in ACAF group (significant differences were identified in the left side at C3/4 , C4/5 , C6/7 level, and in the right side at C4/5 level when compared with ACCF). And decompression width was significantly greater than the transverse diameter of spinal cord in ACAF group. Comparatively, there existed no significant difference in the ACCF group besides the C5 level. CONCLUSION: ACAF can decompress the entrance zone of intervertebral foramina effectively and its decompression width includes the origins and massive running part of bilateral ventral rootlets. Due to its wider decompression range, ACAF can be used as a revision strategy for the patients with failed ACCF.


Assuntos
Ossificação do Ligamento Longitudinal Posterior , Fusão Vertebral , Cadáver , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/cirurgia , Descompressão Cirúrgica/métodos , Humanos , Ossificação do Ligamento Longitudinal Posterior/diagnóstico por imagem , Ossificação do Ligamento Longitudinal Posterior/cirurgia , Estudos Retrospectivos , Fusão Vertebral/métodos , Nervos Espinhais/cirurgia , Resultado do Tratamento
14.
Artigo em Inglês | MEDLINE | ID: mdl-33006928

RESUMO

Recently, super-harmonic ultrasound imaging technology has caused much attention due to its capability of distinguishing microvessels from the tissues surrounding them. However, the fabrication of a dual-frequency confocal transducer is still a challenge. In this work, 270- [Formula: see text] PMN-PT single crystal 1-3 composite and 28- [Formula: see text] PVDF thick film, acting as transmission layer and receiving layer, respectively, are integrated in a novel co-focusing structure. To realize delicate wave propagation control, microwave transmission line theory is introduced to design such structure. Two acoustic filter layers, 13- [Formula: see text] copper layer and 39- [Formula: see text] Epoxy 301 layer, are indispensable and should be added between two piezoelectric layers. Therefore, an acoustic issue can be overcome via an electrical method and the successful achievement of a dual-frequency (5 MHz/30 MHz) ultrasound transducer with a confocal distance of 8 mm can be realized. The super-harmonic ultrasound imaging experiment is conducted using this kind of device. The 3-D image of 110- [Formula: see text]-diameter phantom tube injected with microbubbles can be obtained. These promising results demonstrate that this novel dual-frequency (5 MHz/30 MHz) confocal ultrasound transducer is potentially usable for microvascular medical imaging application in the future.


Assuntos
Microbolhas , Transdutores , Microvasos/diagnóstico por imagem , Imagens de Fantasmas , Ultrassonografia
15.
Oncol Lett ; 20(6): 353, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33123264

RESUMO

The aim of the present study was to determine the effect of microRNA (miR)-155-5p on the expression of testican-1 (SPOCK1) and the invasion and migration of prostate cancer cells in vitro. Bioinformatics analysis and molecular biology assays revealed that SPOCK1 may be a direct target gene of miR-155-5p. In addition, a negative correlation was identified between SPCOK1 and miR-155-5p expression in prostate tumor tissues and cell lines. miR-155-5p mimic transfection inhibited SPOCK1 expression in PC3 cells and decreased cell migration and invasion abilities, while the expression of vimentin, N-cadherin, E-cadherin, ß-catenin, matrix metalloproteinase (MMP)3 and MMP9 was upregulated. In summary, SPOCK1 was found to be a target gene of miR155-5p in prostate cancer, and miR-155-5p acts as a tumor-suppressor gene and may inhibit SPOCK1-mediated prostate cancer progression.

16.
Micromachines (Basel) ; 11(5)2020 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-32455674

RESUMO

Based on a modified dice-and-fill technique, a PIN-PMN-PT single crystal 1-3 composite with the kerf of 12 µm and pitch of 50 µm was prepared. The as-made piezoelectric composite material behaved with high piezoelectric constant (d33 = 1500 pC/N), high electromechanical coefficient (kt = 0.81), and low acoustic impedance (16.2 Mrayls). Using lithography and flexible circuit method, a 48-element phased array was successfully fabricated from such a piezoelectric composite. The array element was measured to have a central frequency of 20 MHz and a fractional bandwidth of approximately 77% at -6 dB. Of particular significance was that this PIN-PMN-PT single crystal 1-3 composite-based phased array exhibits a superior insertion loss compared with PMN-PT single crystal and PZT-5H-based 20 MHz phased arrays. The focusing and steering capabilities of the obtained phased array were demonstrated theoretically and experimentally. These promising results indicate that the PIN-PMN-PT single crystal 1-3 composite-based high frequency phased array is a good candidate for ultrasound imaging applications.

17.
Materials (Basel) ; 11(9)2018 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-30189636

RESUMO

Approximately 25 µm Pb(Mg1/3Nb2/3)O3⁻PbTiO3 (PMN-PT) thick film was synthesized based on a sol-gel/composite route. The obtained PMN-PT thick film was successfully transferred from the Silicon substrate to the conductive silver epoxy using a novel wet chemical method. The mechanism of this damage free transfer was explored and analyzed. Compared with the film on Silicon substrate, the transferred one exhibited superior dielectric, ferroelectric and piezoelectric properties. These promising results indicate that transferred PMN-PT thick film possesses the capability for piezoelectric device application, especially for ultrasound transducer fabrication. Most importantly, this chemical route opens a new path for transfer of thick film.

18.
Nanoscale ; 9(29): 10212-10218, 2017 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-28613338

RESUMO

Magnetic skyrmions have potential applications in novel information devices with excellent energy efficiency. However, the skyrmion Hall effect (SkHE) could cause skyrmions moving in a nanotrack to get annihilated at the track edge. In this work, we discovered that the SkHE is depressed by modifying the magnetic structure at the edge of a track, and thus the skyrmion can move in almost a straight line at a high speed. Unlike the inner part of a track with perpendicular magnetic anisotropy, the edge layer exhibits in-plane magnetic anisotropy, and the orientation of edge moments is opposite that at the perimeter of skyrmions nearby. As a result, an enhanced repulsive force acts on the skyrmion to oppose the Magnus force that causes the SkHE. Additionally, the Dzyaloshinskii-Moriya interaction (DMI) constant of the edge layer also matters. When there is no DMI at the edge layer, the transverse displacement of the skyrmion can be depressed effectively when the width of the edge layer is sufficiently large. However, when the inner part and the edge share the same DMI constant, non-monotonically varied transverse displacement occurs because of the Néel-wall-like structure at the edge layer.

19.
Mol Med Rep ; 15(4): 1800-1806, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28260019

RESUMO

Orthodontic tooth movement is a process stimulated and maintained by external tensile stress; periodontal ligament remodeling serves an important role during this process. However, the function and underlying mechanism of periostin (PN) during orthodontic periodontal ligament remodeling remain unclear. The present study established in vitro and in vivo models of orthodontic treatment to investigate the expression levels of PN under conditions of external tensile stress load. These results indicated that tensile stress load increased the expression levels of PN in mouse peridontal ligaments and human periodontal ligament cells (hPDLCs), during orthodontic tooth movement. Furthermore, the present study demonstrated that the expression levels of PN were regulated by transforming grown factor ß, and that PN promotes type I collagen and α­smooth muscle actin expression levels in hPDLCs. Therefore, PN may be essential for periodontal ligament remodeling during orthodontic treatment, and therefore may represent a potential therapeutic target.


Assuntos
Moléculas de Adesão Celular/genética , Ligamento Periodontal/citologia , Ligamento Periodontal/metabolismo , Estresse Mecânico , Técnicas de Movimentação Dentária , Adolescente , Adulto , Animais , Moléculas de Adesão Celular/análise , Moléculas de Adesão Celular/metabolismo , Células Cultivadas , Criança , Colágeno Tipo I/metabolismo , Feminino , Humanos , Masculino , Camundongos Endogâmicos C57BL , RNA Mensageiro/genética , Fator de Crescimento Transformador alfa/metabolismo , Regulação para Cima , Adulto Jovem
20.
Gynecol Obstet Invest ; 82(3): 230-239, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27505004

RESUMO

OBJECTIVE: The study aimed to investigate cyclin-dependent kinase 14 (CDK14) and its co-function with Wnt signaling pathway on cell proliferation, migration and invasion in ovarian cancer. METHODS: CDK14 expressions were detected by quantitative real-time polymerase chain reaction. The expressions c-Myc, cyclinD1, PFTK1, ki67 and OGT were examined by Western blot. MTT assay was applied to observe cell proliferation after transfection of pEGFP-N1/CDK14-siRNA and pEGFP-N1 into SKOV3 cells, and scratch test and Transwell assay to observe invasion and migration ability. Transfected tumor model in nude mice was established. RESULTS: CDK14 was upregulated in the ovarian cancer tissues and cell lines (both p < 0.05). Expressions of downstream molecules in Wnt signaling pathway as well as the proliferation, invasion and migration ability of the SKOV3 cells were reduced when CDK14 was inhibited (all p < 0.05). The expression of ß-catenin in the nucleus was also decreased when CDK14 was inhibited (p < 0.05). In the transfected tumor model of nude mice, the results showed, compared with the pEGFP-N1 group and blank control group, that the expressions of c-Myc, cyclinD1, PFTK1, ki67 and OGT in the pEGFP-N1/CDK14-siRNA group in the transplantation tumor tissues decreased significantly (all p < 0.05). CONCLUSION: CDK14 suppression-mediated Wnt signaling pathway can inhibit cell proliferation, invasion and migration in ovarian cancer.


Assuntos
Movimento Celular , Proliferação de Células , Quinases Ciclina-Dependentes/fisiologia , Invasividade Neoplásica/patologia , Neoplasias Ovarianas/patologia , Via de Sinalização Wnt/fisiologia , Adulto , Idoso , Animais , Linhagem Celular Tumoral , Núcleo Celular , Feminino , Humanos , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Transplante de Neoplasias , RNA Interferente Pequeno , Transfecção
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