ABSTRACT
Iron is considered as an attractive alternative material for bioresorbable scaffolds (BRS). The sirolimus eluting iron bioresorbable scaffold (IBS), developed by Biotyx Medical (Shenzhen, China), is the only iron-based BRS with an ultrathin-wall design. The study aims to investigate the long-term efficacy, safety, biocompatibility, and lumen changes during the biodegradation process of the IBS in a porcine model. A total of 90 IBSs and 70 cobalt-chromium everolimus eluting stents (EES) were randomly implanted into nonatherosclerotic coronary artery of healthy mini swine. The multimodality assessments including coronary angiography, optical coherence tomography, micro-computed tomography, magnetic resonance imaging, real-time polymerase chain reaction (PCR), and histopathological evaluations, were performed at different time points. There was no statistical difference in area stenosis between IBS group and EES group at 6 months, 1year, 2 years and 5 years. Although the scaffolded vessels narrowed at 9 months, expansive remodeling with increased mean lumen area was found at 3 and 5 years. The IBS struts remained intact at 6 months, and the corrosion was detectable at 9 months. At 5 years, the iron struts were completely degraded and absorbed in situ, without in-scaffold restenosis or thrombosis, lumen collapse, aneurysm formation, and chronic inflammation. No local or systemic toxicity and abnormal histopathologic manifestation were found in all experiments. Results from real-time PCR indicated that no sign of iron overload was reported in scaffolded segments. Therefore, the IBS shows comparable efficacy, safety, and biocompatibility with EES, and late lumen enlargement is considered as a unique feature in the IBS-implanted vessels.
ABSTRACT
Power ultrasound is widely used in industrial production, medical equipment, aerospace, and other fields. Currently, there are two main types of commonly used power generation devices: piezoelectric ultrasonic transducers and magnetostrictive ultrasonic transducers. However, in certain situations with limited external dimensions, the applications of existing power ultrasound devices are limited. In nature, leaf-cutting ants excite vibrations through their tiny organs. Inspired by the vibratory organs of leaf-cutting ants, a new type of biomimetic ultrasonic vibrator (BUV) comprising a scraper, dentate disc, and fixture system was proposed, fabricated, and tested in this study. The experimental results showed that the BUV could operate in the frequency range of 16.8-19 kHz. Within the working frequency range, the vibration of the BUV was stable and the amplitude of the vibration displacement was greater than 22 µm. The operating frequency band of the BUV was broader than those of the piezoelectric and magnetostrictive ultrasonic transducers. In addition, the BUV can cut soft rubber and pig tissues with sufficient output power and load-carrying capacity. The BUV, as a new type of power ultrasonic excitation device, is expected to be applied in high-power micro operating scenarios, such as minimally invasive surgical instruments.
ABSTRACT
Magnetic micro/nanorobots are promising platforms for targeted drug delivery, and their construction with soft and flexible features has received extensive attention for practical applications. Despite significant efforts in this field, facile fabrication of magnetic microrobots with flexible structures and versatility in targeted therapy remains a big challenge. Herein, we proposed a novel universal strategy to fabricate a biohybrid flexible sperm-like microrobot (BFSM) based on a Chlorella (Ch.) cell and artificial flagella, which showed great potential for targeted chemo-photothermal therapy for the first time. In this approach, microspherical Ch. cells were utilized to construct the microrobotic heads, which were intracellularly deposited with core-shell Pd@Au, extracellularly magnetized with Fe3O4, and further loaded with anticancer drug. The magnetic heads with excellent photothermal and chemotherapeutic capability were further assembled with flexible polypyrrole nanowires via biotin-streptavidin bonding to construct the BFSMs. Based on the exquisite head-to-tail structures, the BFSMs could be effectively propelled under precessing magnetic fields and move back and forth without a U-turn. Moreover, in vitro chemo-photothermal tests were conducted to verify their performance of targeted drug delivery toward localized HeLa cells. Due to this superior versatility and facile fabrication, the BFSMs demonstrated great potential for targeted anticancer therapy.
Subject(s)
Photothermal Therapy , Humans , HeLa Cells , Robotics , Drug Delivery Systems , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Doxorubicin/chemistry , Doxorubicin/pharmacology , Polymers/chemistry , Nanowires/chemistry , Gold/chemistryABSTRACT
The accurate perception of multiple flight parameters, such as the angle of attack, angle of sideslip, and airflow velocity, is essential for the flight control of micro air vehicles, which conventionally rely on arrays of pressure or airflow velocity sensors. Here, we present the estimation of multiple flight parameters using a single flexible calorimetric flow sensor featuring a sophisticated structural design with a suspended array of highly sensitive vanadium oxide thermistors. The proposed sensor achieves an unprecedented velocity resolution of 0.11 mm·s-1 and angular resolution of 0.1°. By attaching the sensor to a wing model, the angles of attack and slip were estimated simultaneously. The triaxial flight velocities and wing vibrations can also be estimated by sensing the relative airflow velocity due to its high sensitivity and fast response. Overall, the proposed sensor has many promising applications in weak airflow sensing and flight control of micro air vehicles.
ABSTRACT
Hydrodynamic pressure sensors offer an auxiliary approach for ocean exploration by unmanned underwater vehicles (UUVs). However, existing hydrodynamic pressure sensors often lack the ability to monitor subtle hydrodynamic stimuli in deep-sea environments. In this study, we present the development of a deep-sea hydrodynamic pressure sensor (DSHPS) capable of operating over a wide range of water depths while maintaining exceptional hydrodynamic sensing performance. The DSHPS device was systematically optimized by considering factors such as piezoelectric polyvinylidene fluoride-trifluoroethylene/barium titanate [P(VDF-TrFE)/BTO] nanofibers, electrode configurations, sensing element dimensions, integrated circuits, and packaging strategies. The optimized DSHPS exhibited a remarkable pressure gradient response, achieving a minimum pressure difference detection capability of approximately 0.11 Pa. Additionally, the DSHPS demonstrated outstanding performance in the spatial positioning of dipole sources, which was elucidated through theoretical charge modeling and fluid-structure interaction (FSI) simulations. Furthermore, the integration of a high Young's modulus packaging strategy inspired by fish skull morphology ensured reliable sensing capabilities of the DSHPS even at depths of 1000 m in the deep sea. The DSHPS also exhibited consistent and reproducible positioning performance for subtle hydrodynamic stimulus sources across this wide range of water depths. We envision that the development of the DSHPS not only enhances our understanding of the evolutionary aspects of deep-sea canal lateral lines but also paves the way for the advancement of artificial hydrodynamic pressure sensors.
ABSTRACT
Microorganisms have attracted much attention to act as biotemplates for fabricating micro/nanostructured functional particles. However, it is still challenging to produce tunable hierarchical particles based on microorganisms with intricate architectures and superior stability. Herein, a novel strategy is developed to fabricate biohybrid urchin-like magnetic ZnO microspheres based on Chlorella (Ch.) with tunable hierarchical core-shell structures. Using Ch. cells as microspherical templates, Fe3 O4 nanoparticles and ZnO nanorod (NR) arrays are deposited in sequence to form the final biohybrid heterostructure microspheres (Ch.@Fe3 O4 @ZnO NRs). Ordered growth and structural regulation of 3D ZnO NR arrays are achieved via a facile and controllable manner. Compared with the prepared microspheres with diverse structure configurations of ZnO shells, the Ch.@Fe3 O4 @ZnO NRs possess excellent light absorption and photoelectrocatalysis performance toward tetracycline degradation (normalized apparent rate constant, k = 366.3 h-1 g-1 ), which is significantly larger than that of ZnO nanoflower/nanoparticle loaded types. It also proves that the synergistic enhancement of well-oriented ZnO NR arrays, heterojunction structures, and biomass features is the fundamental reason for outstanding photoelectrocatalytic activity. Due to the remarkable stability and versatility, this work provides abundant opportunities to construct biohybrid multilevel micro/nanostructures with significant potentials for practical applications.
ABSTRACT
Nanostructured silica-based materials have great potential as drug delivery vehicles for precise and personalized medical applications. As natural nanostructured silica, diatomite biosilica (DB) is recognized as a novel carrier to construct oral/parenteral smart drug delivery systems due to high surface area, biocompatibility, and applicability at low cost, yet the related studies on its use in local delivery routes are still scarce. Herein, we proposed a novel strategy to develop multifunctional nasal drug delivery vehicles based on DB, and demonstrated their versatile performance for enhanced treatment of allergic rhinitis (AR). As a proof of concept, the purified DB microparticles were loaded with budesonide as an anti-inflammatory model drug, and further processed via surface modification to graft polydopamine and carboxymethyl chitosan layers. The synthesized microcapsules exhibited remarkable mucin binding capacity and antibacterial activity against Staphylococcus aureus. Besides, toxicity evaluation with human skin fibroblast cells and hemolysis tests indicated their high biocompatibility. Moreover, in vitro drug release results demonstrated pH-responsive release performance of the microcapsules under simulated AR environment (pH 5.0, 35 °C). Hence, this study provides a facile and reliable approach to construct DB-based mucoadhesive nasal drug delivery vehicles, showing great potential for treatment of allergic airway inflammatory diseases.
Subject(s)
Chitosan , Diatomaceous Earth , Rhinitis, Allergic , Humans , Capsules , Drug Delivery Systems/methods , Silicon Dioxide , Anti-Inflammatory Agents , Rhinitis, Allergic/drug therapy , Drug Liberation , Drug CarriersABSTRACT
Cartilage destruction caused by inflammation is a clinical challenge. Many studies have investigated cartilage destruction in adults, but little research was conducted on children. In this study, the protective effect of gold nanoparticles (AuNPs) on the cartilage of children was realized by counteracting chondrocyte apoptosis and extracellular matrix (ECM) degradation in a young mouse model of lipopolysaccharide (LPS)-induced growth plate (GP) cartilage damage. Initially, engineered AuNPs can be efficiently absorbed by chondrocytes, approximately 20 times the amount absorbed by macrophages, resulting in a 29% ± 0.05% increase in chondrocyte viability. Then, AuNPs exposure significantly reduced the release of inflammatory cytokines and secretion of ECM degradation factors induced by LPS. Subsequently, AuNPs were applied to resist LPS-induced cartilage destruction in young mice. AuNPs inhibited the formation of gaps, without chondrocytes and extracellular matrix, between the proliferative and hypertrophy zones of the GP cartilage, and the gaps were noticeable in the LPS group. This finding can be attributed to the capability of AuNPs to reduce the LPS-induced apoptosis rate of mouse chondrocytes by 72.38% and the LPS-induced ECM degradation rate by 70.89%. Further analysis demonstrated that remission is partly due to AuNPs' role in maintaining the balance of catabolic and anabolic factors in the ECM. Altogether, these findings indicate that AuNPs can partially protect the cartilage of children from inflammatory damage by suppressing chondrocyte apoptosis and ECM degradation.
ABSTRACT
Background: Most patients undergoing left atrial appendage closure (LAAC) are older adult individuals with atrial fibrillation (AF) and many comorbidities, which may elevate the risk for complications associated with contrast agents with the fluoroscopic image-guided procedure. This retrospective cohort study of patients with AF at high risk for use of contrast agents compared the feasibility and safety of LAAC using percutaneous and non-fluoroscopic procedure with transesophageal echocardiography (TEE) as the only image guidance relative to those under fluoroscopic image guidance. Methods: In this retrospective study, we enrolled 126 patients with AF who underwent LAAC from September 2017 to December 2020. Patients were divided into 2 groups based on the imaging guidance modality: a TEE group (n=32) and a fluoroscopic group (n=94). We analyzed the differences in complete closure rates and device- and procedure-related complications between the 2 groups. Continuous variables were assessed using the Student t-test or Mann-Whitney test, while categorical variables were evaluated using Pearson chi-squared test or Fisher exact test. Propensity-score matching was used to adjust for baseline differences. Results: Propensity-score matching yielded 25 pairs of patients with similarly distributed age (72.9±6.9 vs. 73.1±4.9 years; P=0.925), gender (10:15 vs. 11:14; P>0.99), weight (68.3±11.2 vs. 68.1±12.3 kg; P=0.948), and alanine aminotransferase level (20.0±9.8 vs. 22.5±14.2 U/L; P=0.482). The LAA was successfully occluded in all patients, and the TEE group showed similar results to the fluoroscopic group in terms of success rate (100% vs. 100%; P>0.99) and hospitalization duration [5.0 (IQ1-IQ3: 3.0-7.0) vs. 5.0 (IQ1-IQ3: 3.0-6.0) days; P=0.498]. The groups also demonstrated comparable complication rates, with 1 (4.2%) case of pericardial effusion and 1 (4.2%) case of residual shunt in the TEE group, and 5 (20%) cases of residual shunt, 1 (4.2%) case of pericardial effusion, 1 (4.2%) case of myocardial infarction, and 1 (4.2%) case of access-related complications in the fluoroscopic group. There were no deaths. The overall incidence rate of procedure-related complications (6.2% vs. 18.1%, P=0.153) at mean 22.2±4.5 months follow-up between the 2 groups was similar. Conclusions: In patients with AF of high risk for use of contrast agents, LAAC under non-fluoroscopic guidance appears feasible and safe with similar outcomes to that under fluoroscopic guidance.
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RATIONALE: With the advancement of targeted therapies, epidermal growth factor receptor tyrosine kinase inhibitors have become the preferred initial treatment for patients with advanced epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer. Osimertinib, a third-generation epidermal growth factor receptor tyrosine kinase inhibitor, is effective against exon 19 and 21 mutations as well as the T790M mutation. It has been approved by both the food and drug administration and European Medicines Agency for the treatment of non-small cell lung cancer patients with locally advanced or metastatic EGFR-mutated tumors, including those who have acquired T790M mutations. PATIENT CONCERNS: To evaluate the effectiveness of osimertinib in treating patients with EGFR-mutated advanced lung adenocarcinoma and bone metastases, we present the treatment outcomes of 3 patients with EGFR 19 deletion-mutated advanced lung adenocarcinoma and bone metastases who received osimertinib treatment in recent years. All 3 cases involved elderly female patients, aged 62, 62, and 54, respectively. DIAGNOSES: All 3 cases exhibited a diagnosis of pulmonary adenocarcinoma accompanied by osseous metastases, with genetic testing revealing the presence of an EGFR 19del mutation. INTERVENTIONS: In the first case, following 17 months of gefitinib therapy, disease progression prompted a switch to osimertinib treatment. In the second case, bone metastases were detected after 20 months of pemetrexed-carboplatin chemotherapy, leading to a transition to osimertinib therapy. In the third case, after 11 months of erlotinib treatment, bone metastases were identified. Subsequent interventions, including radiation therapy, pemetrexed-carboplatin chemotherapy, pemetrexed-bevacizumab maintenance therapy, and docetaxel chemotherapy, failed to arrest the progression of bone metastases. As a result, a combination of osimertinib and anlotinib targeted therapy was administered. OUTCOMES: All 3 patients experienced relatively good and favorable survival outcomes, with a progression-free survival of 22.7 months, 12 months, and 17.7 months, respectively. LESSONS: These cases suggest that osimertinib is a promising treatment option for patients with EGFR 19 deletion-mutated lung adenocarcinoma and bone metastases, although further clinical studies are needed to confirm its efficacy.
Subject(s)
Adenocarcinoma of Lung , Bone Neoplasms , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Aged , Female , Humans , Adenocarcinoma of Lung/drug therapy , Adenocarcinoma of Lung/genetics , Bone Neoplasms/drug therapy , Bone Neoplasms/genetics , Carboplatin , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/genetics , ErbB Receptors/genetics , Lung Neoplasms/drug therapy , Lung Neoplasms/genetics , Mutation , Pemetrexed , Protein Kinase Inhibitors/therapeutic use , United States , /therapeutic useABSTRACT
Aiming to develop a self-powered bioelectric tag for fish behavioral studies, here we present a fish-wearable piezoelectric nanogenerator (FWPNG) that can simultaneously harvest the strain energy and the flow impact energy caused by fish-tailing. The FWPNG is fabricated by transferring a 2 µm-thick Nb0.02-Pb(Zr0.6Ti0.4)O3 (PZT) layer from a silicon substrate to a spin-coated polyimide film via a novel zinc oxide (ZnO) release process. The open-circuit voltage of the strain energy harvester reaches 2.3 V under a strain of 1% at an ultra-low frequency of 1 Hz, and output voltage of the impact energy harvester reaches a 0.3 V under a pressure of 82.6 kPa at 1 Hz, which is in good agreement with our theoretical analysis. As a proof-of-concept demonstration, an event-driven underwater acoustic transmitter is developed by utilizing the FWPNG as a trigger switch. Acoustic transmission occurs when the amplitude of fish-tailing is larger than a preset threshold. The dual-modal FWPNG device shows the potential application in self-powered biotags for animal behavioral studies and ocean explorations.
ABSTRACT
Many living organisms exhibit exceptional capabilities and have evolved effective strategies to synthesize impact-resistant and damage-tolerant structures. One such example can be observed in the rapid mandible strikes ofOdontomachus monticola, a species of trap-jaw ants from the ponerine subfamily. During trap-jaw strikes, the mandibles can achieve peak speeds of 35.42 m s-1, and the maximum acceleration can reach 71 729 g within an average duration of 0.18 ms. The extreme acceleration results in instantaneous mandible strike forces that can exceed 330 times the ant's body weight, withstanding thousands of impacts. A natural impact-resistant fibrous helicoidal structure is found in the mandibles of trap-jaw ants. This microstructure is characterized by periodic modulus oscillations that increase energy absorption and improve stress redistribution, offering added protection against damage from impact loading. A carbon fiber reinforced helicoidal composite is fabricated based on the microstructure of the trap-jaw ant's mandibles. The results show that the helicoidal composite with a 12° helical-fiber exhibits higher residual strength, making it more capable of withstanding strong collisions. The catastrophic propagation of damage along the thickness direction is prevented by in-plane spreading and redirection of cracks. This research provides useful references for fabricating bionic impact-resistant composites.
Subject(s)
Ants , Animals , Bionics , Mandible , Body Weight , Carbon FiberABSTRACT
Expanded polytetrafluoroethylene (ePTFE) is promising in biomedical fields such as covered stents and plastic surgery owing to its excellent biocompatibility and mechanical properties. However, ePTFE material prepared by the traditional biaxial stretching process is with thicker middle and thinner sides due to the bowing effect, which poses a major problem in industrial-scale fabrication. To solve this problem, we design an olive-shaped winding roller to provide the middle part of the ePTFE tape with a greater longitudinal stretching amplitude than the two sides, so as to make up for the excessive longitudinal retraction tendency of the middle part when it is transversely stretched. The as-fabricated ePTFE membrane has, as designed, uniform thickness and node-fibril microstructure. In addition, we examine the effects of mass ratio of lubricant to PTFE powder, biaxial stretching ratio and sintering temperature on the performance of the resultant ePTFE membranes. Particularly, the relation between the internal microstructure of the ePTFE membrane and its mechanical properties is revealed. Besides stable mechanical properties, the sintered ePTFE membrane exhibits satisfactory biological properties. We make a series of biological assessments including in vitro hemolysis, coagulation, bacterial reverse mutation and in vivo thrombosis, intracutaneous reactivity test, pyrogen test and subchronic systemic toxicity test; all of the results meet the relevant international standards. The muscle implantation of the sintered ePTFE membrane into rabbits indicates acceptable inflammatory reactions of our sintered ePTFE membrane fabricated on industrial scale. Such a medical-grade raw material with the unique physical form and condensed-state microstructure is expected to afford an inert biomaterial potentially for stent-graft membrane.
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Drilling of high-strength T800 carbon fiber reinforced plastic (CFRP) are widely employed in current aviation industry. Drilling-induced damages frequently occur and affect not only the load carrying capacity of components but also the reliability. As one of effective methods to reduce the drilling-induced damages, advanced tool structures have been widely used. Nevertheless, it is still difficult to realize high machining accuracy and efficiency by this method. This paper compared three different drill bits to evaluate the drilling performance of T800 CFRP composites and the results showed that the dagger drill was a good choice to drill T800 CFRP considering the lowest thrust force and damages. On this basis, ultrasonic vibration was successfully imposed on dagger drill to further improve the drilling performance. The experimental results showed that ultrasonic vibration reduced the thrust force and surface roughness with a maximum decrease of 14.1 % and 62.2 % respectively. Moreover, the maximum hole diameter errors were decreased from 30 µm in CD to 6 µm in UAD. Besides, the mechanisms of force reduction and hole quality improvement by ultrasonic vibration were also revealed. The results suggest that the combination of ultrasonic vibration and dagger drill is a promising strategy for high performance drilling CFRP.
ABSTRACT
The majority of living organisms demonstrate remarkable attributes and have evolved effective mechanisms for synthesizing impact-resistant and damage-tolerant structures. One exemplary instance is the rapid mandible strikes exhibited by trap-jaw ants, which are a highly aggressive species of terrestrial social organisms. An impact-resistant sinusoidal helicoidal architecture is discovered in the mandibles of trap-jaw ants. The bioinspired laminate with a bi-sinusoidal helicoidal structure was manufactured using unidirectional carbon fiber prepreg by mold press forming. This study examines the impact resistance and damage tolerance of a bionic laminate through low velocity impact, computed tomography, and compression after impact tests. The results demonstrate that bionic laminates effectively limit damage propagation within the plane while enhancing energy dissipation capacity. The sinusoidal helicoidal configuration enhances cushioning capability against impact forces, retards penetration under higher loads, hinders crack propagation, and improves residual strength. Bionic laminates provide a valuable solution for damage tolerance through the resistance to through-the-thickness loads. STATEMENT OF SIGNIFICANCE: Helicoidal and sinusoidal helicoidal microstructures have been identified in the cross-section of the jaws of trap-jaw ants. The multiple waviness ratio parameters are designed for fabricating a sinusoidal helicoidal structure laminate using unidirectional carbon fiber prepreg through the mold press forming technique. This results in a damage-tolerant mechanism characterized by reduced delamination damage, which leads to a stiffer mechanical response. Meanwhile, it enhances resistance to crack propagation, leading to the formation of discontinuous delamination areas and the accumulation of sub-critical failures. Additionally, the sinusoidal helicoidal structure laminate combines the cushioning performance of bi-sinusoidal arrangements with the enhanced impact resistance of helical arrangements. This design delays penetration at higher loads, resulting in increased residual strength.
Subject(s)
Ants , Animals , Carbon Fiber , Ants/physiology , Jaw , MandibleABSTRACT
We successfully prepared highly anisotropic conductive composites (ACCs) made of Ag-coated glass microbeads/UV adhesive via electric field-induced alignment, which was achieved using custom patterned microelectrode arrays. An optimized AC electric field (2 kV/cm, 1 kHz) with pole-plate spacing (50 µm) was utilized to effectively assemble the microbeads into chain arrays, which were precisely positioned on the microelectrode arrays to construct ordered conductive channels. In this case, tangling and cross-connection of the assembled microchains could be reduced, resulting in enhanced performance of the ACCs with high conductivity as well as excellent anisotropy. With a minor loading (3 wt %), the conductivity in the alignment direction could reach â¼24.9 S/m, which was the highest among the reported ACCs to the best of our knowledge, and it could also be 6 orders of magnitude higher than that within the plane. Besides, the samples exhibited high reliability in wire connections with low resistances. Due to these fascinating properties, the ACCs demonstrate promising applications for reliable electrical interconnects and integrated circuits.
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BACKGROUND: Osteoporosis is a major clinical problem in elderly men and women. The correlation between total cholesterol and bone mineral density remains controversial. NHANES is the cornerstone for national nutrition monitoring to inform nutrition and health policy. METHODS: Sample sizes and the location of the study and the time when it was conducted: we obtained 4236 non-cancer elderly from NHANES (National Health and Nutrition Examination Survey) database from 1999 to 2006. Data were analyzed with the use of the statistical packages R and EmpowerStats. We analyzed the relationship between total cholesterol and lumbar bone mineral density. We performed research population description, stratified analysis, single factor analysis, multiple equation regression analysis, smooth curve fitting, and threshold effect and saturation effect analysis. RESULTS: A significant negative association between serum cholesterol levels and bone mineral density of the lumbar spine in US non cancer affected older adults aged 60 years or older. Older adults ≥ 70 years of age had an inflection point at 280 mg / dl, and those with moderate physical activity had an inflection point at 199 mg / dl, The smooth curves they fitted were all U-shaped. CONCLUSIONS: There is a negative association between total cholesterol and lumbar spine bone mineral density in non-cancer elderly greater than or equal to 60 years of age.
Subject(s)
Bone Density , Lumbar Vertebrae , Male , Aged , Humans , Female , Nutrition Surveys , Absorptiometry, Photon , Lumbar Vertebrae/diagnostic imaging , CholesterolABSTRACT
Polyimides are widely used in the MEMS and flexible electronics fields due to their combined physicochemical properties, including high thermal stability, mechanical strength, and chemical resistance values. In the past decade, rapid progress has been made in the microfabrication of polyimides. However, enabling technologies, such as laser-induced graphene on polyimide, photosensitive polyimide micropatterning, and 3D polyimide microstructure assembly, have not been reviewed from the perspective of polyimide microfabrication. The aims of this review are to systematically discuss polyimide microfabrication techniques, which cover film formation, material conversion, micropatterning, 3D microfabrication, and their applications. With an emphasis on polyimide-based flexible MEMS devices, we discuss the remaining technological challenges in polyimide fabrication and possible technological innovations in this field.
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Drug delivery systems with high-targeted doses can minimize excipients, reduce side effects, and improve efficacy. Human blood circulation is a complex circulatory system, and the motion control of microrobots in the static flow field in vitro is completely different from in vivo. How to achieve precise counterflow motion for targeted drug delivery without vascular blockage and immune rejection is the biggest challenge for micro-nano robots. Here, we propose a control method that enables vortex-like paramagnetic nanoparticle swarm (VPNS) to move upstream against the flow. By mimicking the clustering motion of wild herring schools and the rolling of leukocytes, VPNS are incredibly stable even when subjected to high-intensity jet impacts in the blood environment, can travel upstream, anchor at the target location, and dissipate when the magnetic field is withdrawn, which greatly reduces the risk of thrombosis. VPNS can also upstream along the vessel wall without an additional energy source and has a marked targeted therapeutic effect on subcutaneous tumors.
ABSTRACT
With recent advances in treatment modalities, the survival time for patients with small cell lung cancer (SCLC) has increased, along with the likelihood of recurrence of a second primary tumor. However, patient treatment options and prognosis remain uncertain. This research evaluated the survival rates of patients with SCLC with a second malignancy, aiming to provide new insights and statistics on whether to proceed with more active therapy. SCLC patients were selected based on the Surveillance, Epidemiology, and End Results (SEER) database, updated on April 15, 2021. We defined those with SCLC followed by other cancers (1st of 2 or more primaries) in the sequence number as S-second primary malignant cancer (S-SPM). Those who had other cancers followed by SCLC (2nd of 2 or more primaries) were defined as OC-SCLC. We performed Kaplan-Meier survival analysis, life table analysis, univariate analysis, stratified analysis, and multiple regression analysis of patient data. We considered the difference statistically meaningful at P < .05. After selection, data for 88,448 participants from the SEER database was included in our analysis. The mean survival time for patients with S-SPM was 69.349 months (95% confidence interval [CI]: 65.939, 72.759), and the medium duration of survival was 34 months (95% CI: 29.900, 38.100). Univariate analysis showed that for overall survival, the hazard ratio (HR) of S-SPM was 0.367 (95% CI: 0.351, 0.383), which was 0.633 lower than that of patients with solitary SCLC and 0.606 lower than that of patients with OC-SCLC. For cancer-specific survival (CSS), the HR of S-SPM was 0.285 (95% CI: 0.271, 0.301), which was 0.715 lower than for patients with solitary SCLC and 0.608 lower than that for patients with OC-SCLC. Multiple regression analysis showed that the HR values of S-SPM were lower than those of patients with single SCLC and those with OC-SCLC, before and after adjustment for variables. Kaplan-Meier survival curves showed that patients with S-SPM had significantly better survival times than the other groups. The survival time and prognosis of patients with S-SPM were clearly superior to those with single SCLC and OC-SCLC.