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1.
Bioengineering (Basel) ; 11(4)2024 Mar 25.
Article in English | MEDLINE | ID: mdl-38671730

ABSTRACT

This study proposed a composite tibia defect scaffold with radial gradient porosity, utilizing finite element analysis to assess stress in the tibial region with significant critical-sized defects. Simulations for scaffolds with different porosities were conducted, designing an optimal tibia defect scaffold with radial gradient porosity for repairing and replacing critical bone defects. Radial gradient porosity scaffolds resulted in a more uniform stress distribution, reducing titanium alloy stiffness and alleviating stress shielding effects. The scaffold was manufactured using selective laser melting (SLM) technology with stress relief annealing to simplify porous structure fabrication. The study used New Zealand white rabbits' tibia defect sites as simulation parameters, reconstructing the 3D model and implanting the composite scaffold. Finite element analysis in ANSYS-Workbench simulated forces under high-activity conditions, analyzing stress distribution and strain. In the simulation, the titanium alloy scaffold bore a maximum stress of 122.8626 MPa, while the centrally encapsulated HAp material delivered 27.92 MPa. The design demonstrated superior structural strength, thereby reducing stress concentration. The scaffold was manufactured using SLM, and the uniform design method was used to determine a collection of optimum annealing parameters. Nanoindentation and compression tests were used to determine the influence of annealing on the elastic modulus, hardness, and strain energy of the scaffold.

2.
Cancers (Basel) ; 15(4)2023 Feb 20.
Article in English | MEDLINE | ID: mdl-36831685

ABSTRACT

In today's high-order health examination, imaging examination accounts for a large proportion. Computed tomography (CT), which can detect the whole body, uses X-rays to penetrate the human body to obtain images. Its presentation is a high-resolution black-and-white image composed of gray scales. It is expected to assist doctors in making judgments through deep learning based on the image recognition technology of artificial intelligence. It used CT images to identify the bladder and lesions and then segmented them in the images. The images can achieve high accuracy without using a developer. In this study, the U-Net neural network, commonly used in the medical field, was used to extend the encoder position in combination with the ResBlock in ResNet and the Dense Block in DenseNet, so that the training could maintain the training parameters while reducing the overall identification operation time. The decoder could be used in combination with Attention Gates to suppress the irrelevant areas of the image while paying attention to significant features. Combined with the above algorithm, we proposed a Residual-Dense Attention (RDA) U-Net model, which was used to identify organs and lesions from CT images of abdominal scans. The accuracy (ACC) of using this model for the bladder and its lesions was 96% and 93%, respectively. The values of Intersection over Union (IoU) were 0.9505 and 0.8024, respectively. Average Hausdorff distance (AVGDIST) was as low as 0.02 and 0.12, respectively, and the overall training time was reduced by up to 44% compared with other convolution neural networks.

3.
Sensors (Basel) ; 22(23)2022 Nov 24.
Article in English | MEDLINE | ID: mdl-36501833

ABSTRACT

A novel piezoelectric fiber sensor based on polyvinylidene fluoride piezoelectric (PVDF) doped with graphene is presented. The near-field electrospinning technology was used for developing the sensor. The uniform experimental design method was introduced to determine the ranges of experimental parameters, including the applied voltage, the drum speed range, the graphene doping ratios from 0% to 11 wt% in PVDF solution, and the electrode gap. By experimental results, the conductivities of PVDF solutions with different doping ratios of graphene increased from 19.6 µS/cm to 115.8 µS/cm. Tapping tests were performed to measure the voltages and currents produced by the piezoelectric fibers. The maximum output voltage was 4.56 V at 5 wt% graphene doping ratio in PVDF fibers, which was 11.54 times that of the pure PVDF sensors. Moreover, mechanical properties of the proposed sensor were measured. Motion intention and swallowing test, such as saliva-swallowing and eating, were carried out. When the subject spoke normally, the output voltage of the sensor was between 0.2 and 0.4 V, approximately. Furthermore, when the subject drank water and ate food, the output voltage of the sensor was between 0.5 and 1 V, approximately. The proposed sensor could be used to detect signals of the human body and serve as a wearable device, allowing for more diagnosis and medical treatment.


Subject(s)
Graphite , Silk , Humans , Polyvinyls , Electrodes
4.
Hu Li Za Zhi ; 66(2): 107-114, 2019 Apr.
Article in Chinese | MEDLINE | ID: mdl-30924521

ABSTRACT

This report describes our experience providing nursing care between 7th October and 7th November 2016 to a homosexual male who repeatedly engaged in stress-related suicide attempts and self-harm. Information was collected using comprehensive nursing assessment, observation, and interviews and the health problems of ineffective coping and disabled family coping were identified. Because of affection-related distress and the lack of recognition of his gender orientation by his family, the client engaged repeatedly in self-harm and attempted suicide on several occasions in order to cope with the self-perceived unbearable stress and stressful situations. The authors provided nursing care based on Watson's theory of human caring. We fulfilled the nature of caring, prompted respect and acceptance, and established a therapeutic, interpersonal relationship. We also adopted the concept of suicide intervention, and used the protective factors as the main coping strategies. These approaches allowed the client to acknowledge the events and reactions that may trigger his suicidal ideas, to develop better self-reflection and impulse control, and to mitigate the ideas and behaviors related to suicide and self-harm. Because constant conflicts between the client and his parents hampered a harmonious family relationship, we adopted family-centered care in order to enhance family resilience, which created room for mutual learning and development and reconstructed a healthy family relationship. Our successful results with this case encouraged our writing this paper in order to share this nursing experience with caregivers facing similar client situations and needs.


Subject(s)
Homosexuality, Male/psychology , Nurse-Patient Relations , Nurses/psychology , Suicidal Ideation , Adaptation, Psychological , Empathy , Humans , Male , Nursing Theory
5.
J Urol ; 167(2 Pt 1): 761-7, 2002 Feb.
Article in English | MEDLINE | ID: mdl-11792968

ABSTRACT

PURPOSE: We tested the hypothesis that intracavernous injection of vascular endothelial growth factor (VEGF) can restore erectile function in a rat model of traumatic arteriogenic erectile dysfunction. MATERIALS AND METHODS: Exploration of bilateral internal iliac arteries was performed in 50, 3-month-old male rats. A total of 44 rats underwent bilateral ligation of the internal iliac arteries and 6 that underwent exploration only served as the sham operated group. Minutes later intracavernous injection of phosphate buffered saline (PBS) plus bovine serum albumin in 16 rats, 2 microg. VEGF plus PBS plus BSA in 12 and 4 microg. VEGF plus PBS plus BSA in 16 was performed. At weeks 1, 2 and 6 about a third of the rats in each group underwent electrostimulation of the cavernous nerves to assess erectile function and were then sacrificed. Penile tissues were collected for histochemical and electron microscopy examinations. RESULTS: No impairment of erectile function was noted in sham operated rats. Immediately after arterial ligation all rats showed little or no erectile response to neurostimulation. In PBS treated rats modest recovery of erectile function was noted at week 6. Significant recovery of erectile function was noted in VEGF treated rats at weeks 1 and 2 in the 4 microg. group only and at week 6 in the 2 and 4 microg. groups. Neuronal nitric oxide synthase staining showed a reduction in neuronal nitric oxide synthase positive nerve fibers in the dorsal or intracavernous nerves at week 1. Moderate recovery of neuronal nitric oxide synthase positive nerve fibers was noted in the 2 and 4microg. VEGF treated groups but not in the PBS treated group. Electron microscopy revealed no pathological change in sham operated rats. In dorsal nerves the atrophy of myelinated and nonmyelinated nerve fibers was noted in ligated plus PBS treated rats. Partial recovery was observed in VEGF treated rats. Scattered atrophic smooth muscle cells were seen in PBS and occasionally in VEGF treated rats but not in the sham operated group. The most dramatic findings in VEGF treated rats were hypertrophy and hyperplasia of the endothelial cells, especially those lining the small capillaries. CONCLUSIONS: Ligation of bilateral internal iliac arteries produced a reliable animal model of traumatic arteriogenic erectile dysfunction. Intracavernous injection of VEGF minutes after arterial ligation facilitated the recovery of erectile function.


Subject(s)
Endothelial Growth Factors/pharmacology , Lymphokines/pharmacology , Penile Erection/drug effects , Animals , Disease Models, Animal , Endothelial Growth Factors/therapeutic use , Endothelium/pathology , Erectile Dysfunction/drug therapy , Hyperplasia , Hypertrophy , Iliac Artery/surgery , Immunohistochemistry , Injections, Intralesional , Ligation , Lymphokines/therapeutic use , Male , Neovascularization, Physiologic/drug effects , Nerve Tissue Proteins/metabolism , Nitric Oxide Synthase/metabolism , Nitric Oxide Synthase Type I , Penis/metabolism , Rats , Rats, Sprague-Dawley , Receptor Protein-Tyrosine Kinases , Receptors, Growth Factor , Receptors, Vascular Endothelial Growth Factor , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth Factors
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