40 research outputs found

    The Reliability Model of Artificial Monitoring on the Anomalous Event in Expressway Tunnels and Monte Carlo Simulation

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    Artificial monitoring remains to be a major way to detect anomalous events in expressway tunnels. To estimate the reliability of artificial monitoring on anomalous events in expressway tunnels, the video surveillance and mobile inspection based reliability models of artificial monitoring on the anomalous event in the expressway tunnel were built, and Monte Carlo method was applied to calculate the probability and mean time to detect the anomalous event at the specific time. The results showed that the Monte Carlo method could simulate video surveillance and mobile inspection, and obtain the probability distribution and mean time of detecting anomalous events. The mean time to spot the anomalous event was in reverse relation with the number of inspectors, the time of mobile inspection, and the reliability probability of the monitoring pre-warning system in tunnels and was in positive relationships with the departure interval. Combined with the actual operation cost, the model serves as a basis for the artificial monitoring package

    Endovascular Metal Devices for the Treatment of Cerebrovascular Diseases

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    Cerebrovascular disease involves various medical disorders that obstruct brain blood vessels or deteriorate cerebral circulation, resulting in ischemic or hemorrhagic stroke. Nowadays, platinum coils with or without biological modification have become routine embolization devices to reduce the risk of cerebral aneurysm bleeding. Additionally, many intracranial stents, flow diverters, and stent retrievers have been invented with uniquely designed structures. To accelerate the translation of these devices into clinical usage, an in‐depth understanding of the mechanical and material performance of these metal‐based devices is critical. However, considering the more distal location and tortuous anatomic characteristics of cerebral arteries, present devices still risk failing to arrive at target lesions. Consequently, more flexible endovascular devices and novel designs are under urgent demand to overcome the deficiencies of existing devices. Herein, the pros and cons of the current structural designs are discussed when these devices are applied to the treatment of diseases ranging broadly from hemorrhages to ischemic strokes, in order to encourage further development of such kind of devices and investigation of their use in the clinic. Moreover, novel biodegradable materials and drug elution techniques, and the design, safety, and efficacy of personalized devices for further clinical applications in cerebral vasculature are discussed.Peer reviewe

    Gold Nanorods Conjugated Porous Silicon Nanoparticles Encapsulated in Calcium Alginate Nano Hydrogels Using Microemulsion Templates

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    Porous silicon nanoparticles (PSiNPs) and gold nanorods (AuNRs) can be used as biocompatible nanocarriers for delivery of therapeutics but undesired leakage makes them inefficient. By encapsulating the PSiNPs and AuNRs in a hydrogel shell, we create a biocompatible functional nano carrier that enables sustained release of therapeutics. Here, we report the fabrication of AuNRs-conjugated PSi nanoparticles (AuNRsPSiNPs) through two-step chemical reaction for high capacity loading of hydrophobic and hydrophilic therapeutics with photothermal property. Furthermore, using water-in-oil microemulsion templates, we encapsulate the AuNRsPSiNPs within a calcium alginate hydrogel nanoshell, creating a versatile biocompatible nanocarrier to codeliver therapeutics for biomedical applications. We find that the functionalized nanohydrogel effectively controls the release rate of the therapeutics while maintaining a high loading efficiency and tunable loading ratios. Notably, combinations of therapeutics coloaded in the functionalized nanohydrogels significantly enhance inhibition of multidrug resistance through synergism and promote faster cancer cell death when combined with photothermal therapy. Moreover, the AuNRs can mediate the conversion of near-infrared laser radiation into heat, increasing the release of therapeutics as well as thermally inducing cell damage to promote faster cancer cell death. Our AuNRsPSiNPs functionalized calcium alginate nanohydrogel holds great promise for photothermal combination therapy and other advanced biomedical applications.Peer reviewe

    Multistage signal-interactive nanoparticles improve tumor targeting through efficient nanoparticle-cell communications

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    Communication between biological components is critical for homeostasis maintenance among the convergence of complicated bio-signals. For therapeutic nanoparticles (NPs), the general lack of effective communication mechanisms with the external cellular environment causes loss of homeostasis, resulting in deprived autonomy, severe macrophage-mediated clearance, and limited tumor accumulation. Here, we develop a multistage signal-interactive system on porous silicon particles through integrating the Self-peptide and Tyr-Ile-Gly-Ser-Arg (YIGSR) peptide into a hierarchical chimeric signaling interface with “don’t eat me” and “eat me” signals. This biochemical transceiver can act as both the signal receiver for amantadine to achieve NP transformation and signal conversion as well as the signal source to present different signals sequentially by reversible self-mimicking. Compared with the non-interactive controls, these signal-interactive NPs loaded with AS1411 and tanespimycin (17-AAG) as anticancer drugs improve tumor targeting 2.8-fold and tumor suppression 6.5-fold and showed only 51% accumulation in the liver with restricted hepatic injury.Peer reviewe

    Nanoarchitectonic Engineering of Thermal-Responsive Magnetic Nanorobot Collectives for Intracranial Aneurysm Therapy

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    Stent-assisted coiling is a main treatment modality for intracranial aneurysms (IAs) in clinics, but critical challenges remain to be overcome, such as exogenous implant-induced stenosis and reliance on antiplatelet agents. Herein, we report an endovascular approach for IA therapy without stent grafting or microcatheter shaping, enabled by active delivery of thrombin (Th) to target aneurysms using innovative phase-change material (PCM)-coated magnetite-thrombin (Fe3O4-Th@PCM) FTP nanorobots. The nanorobots are controlled by an integrated actuation system of dynamic torque-force hybrid magnetic fields. With robust intravascular navigation guided by real-time ultrasound imaging, nanorobotic collectives can effectively accumulate and retain in model aneurysms constructed in vivo, followed by controlled release of the encapsulated Th for rapid occlusion of the aneurysm upon melting the protective PCM (thermally responsive in a tunable manner) through focused magnetic hyperthermia. Complete and stable aneurysm embolization was confirmed by postoperative examination and 2-week postembolization follow-up using digital subtraction angiography (DSA), contrast-enhanced ultrasound (CEUS) and histological analysis. The safety of the embolization therapy was assessed through biocompatibility evaluation and histopathology assays. Our strategy, seamlessly integrating secure drug packaging, agile magnetic actuation and clinical interventional imaging, avoids possible exogenous implant rejection, circumvents cumbersome microcatheter shaping, and offers a promising option for IA therapy

    Multistage signal-interactive nanoparticles improve tumor targeting through efficient nanoparticle-cell communications

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    Communication between biological components is critical for homeostasis maintenance among the convergence of complicated bio-signals. For therapeutic nanoparticles (NPs), the general lack of effective communication mechanisms with the external cellular environment causes loss of homeostasis, resulting in deprived autonomy, severe macrophage-mediated clearance, and limited tumor accumulation. Here, we develop a multistage signal-interactive system on porous silicon particles through integrating the Self-peptide and Tyr-Ile-Gly-Ser-Arg (YIGSR) peptide into a hierarchical chimeric signaling interface with “don’t eat me” and “eat me” signals. This biochemical transceiver can act as both the signal receiver for amantadine to achieve NP transformation and signal conversion as well as the signal source to present different signals sequentially by reversible self-mimicking. Compared with the non-interactive controls, these signal-interactive NPs loaded with AS1411 and tanespimycin (17-AAG) as anticancer drugs improve tumor targeting 2.8-fold and tumor suppression 6.5-fold and showed only 51% accumulation in the liver with restricted hepatic injury.</p

    Effects of Corn Varieties and Moisture Content on Mechanical Properties of Corn

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    The purpose of this study is to explore how corn varieties and moisture content affect the mechanical properties of corn with high moisture content (26.0~36.4%). The mechanical properties of corn that affect corn threshing quality are determined by establishing the contact mechanical model of the threshing elements and corn kernels. These mechanical properties of corn include the size characteristics of corn (corn ear weight and corn kernel triaxial size) in addition to the mechanical characteristics of corn (corn elastic modulus, corn kernel breaking force, and corn stalk breaking force). The effects of corn varieties and moisture content on the mechanical properties of corn were tested. The results showed that the corn varieties and moisture content had significant effects on the mechanical properties of corn. Among them, the different levels of moisture content levels have significant differences in the mechanical properties of corn, while corn varieties have different significant differences in the mechanical properties of corn. The ear weight, corn kernel triaxial size, and the axial and radial breaking force of corn pedicels all increased significantly as the moisture content increased. Corn’s elastic modulus, kernel breaking force, and the normal breaking force of corn pedicels all decreased significantly as moisture content increased. The breaking force of corn kernels at different positions is in the order of ventral, lateral, and top surface, and the breaking force of corn pedicels in different directions is in the order of normal, axial, and radial. When the moisture content is between 26.0% and 36.4%, the maximum breaking force of a corn kernel is 401.62 N, and the minimum is 35.47 N. The maximum breaking force of corn pedicels is 32.72 N, and the minimum is 5.37 N. Understanding the influences of these relationships is very important for applications related to the threshing process, such as selecting the threshing mode, designing the threshing mechanism, and setting the threshing parameters

    HIV prevalence and correlated factors among male clients of female sex workers in a border region of China.

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    OBJECTIVES:To assess the prevalence of human immunodeficiency virus (HIV) infection and the correlated risk factors among male clients of female sex workers (FSWs) in a Chinese-Vietnamese border region in Yunnan Province, China. METHODS:A cross-sectional survey was conducted between 2014 and 2015 in Hekou County, Yunnan Province, China. Convenience sampling and snowball sampling methods were used to recruit male clients for a questionnaire survey to collect information on demographics, sexual behavior, and drug use. Blood and urine samples were collected for testing of HIV/sexually transmitted infections (STIs) and drug use. Multivariate logistic regression was used to examine factors correlated with HIV infection. RESULTS:Of 776 respondents who participated in the study, 721 (92.91%) were Chinese and 55 (7.09%) were Vietnamese. Overall HIV prevalence in male clients of FSWs was 2.06%, 128 (16.49%) were infected with HSV-2, and five (0.64%) tested syphilis-positive. Two-thirds (68.81%) of respondents reported always using condoms with FSWs, and 89.05% reported condom use in the last episode of commercial sex. Male clients from Vietnam were significantly more likely to take morphine (9.09%) compared with Chinese male clients of FSWs. Age ≄50 years (OR: 8.11, 95%CI: 1.26-52.16) and morphine positivity (OR: 7.35, 95%CI: 1.42-38.06) were associated with HIV infection in the multivariate logistic regression model. CONCLUSION:The relatively high proportion of male clients of FSWs who have numerous sexual partners and use condoms less frequently make them serve as important bridges for HIV transmission from FSWs to the low-risk general population. The positive association between morphine positivity and HIV infection confirmed illegal drug use as another important route for acquiring HIV infection in addition to sexual transmission, indicating that innovative interventions addressing both drug use and risky sexual behaviors are greatly required for male clients. Respondents aged ≄50 years have a higher risk of HIV infection, which emphasizes that older male clients of FSWs should be focused in future HIV prevention interventions in the border regions of China

    Navigating the Evolving Landscape of Primary Hyperoxaluria: Traditional Management Defied by the Rise of Novel Molecular Drugs

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    Primary hyperoxalurias (PHs) are inherited metabolic disorders marked by enzymatic cascade disruption, leading to excessive oxalate production that is subsequently excreted in the urine. Calcium oxalate deposition in the renal tubules and interstitium triggers renal injury, precipitating systemic oxalate build-up and subsequent secondary organ impairment. Recent explorations of novel therapeutic strategies have challenged and necessitated the reassessment of established management frameworks. The execution of diverse clinical trials across various medication classes has provided new insights and knowledge. With the evolution of PH treatments reaching a new milestone, prompt and accurate diagnosis is increasingly critical. Developing early, effective management and treatment plans is essential to improve the long-term quality of life for PH patients
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