Piezoelectric materials can produce electrical power from the mechanical stimulation and thus, they may accelerate electroactive tissue healing as a promising treatment for traumatic peripheral nerve ...injuries. In this study, a piezoelectric zinc oxide nanogenerator scaffold is manufactured by 3D injectable multilayer biofabrication. The piezoelectric polymeric scaffold displays desirable mechanical and physical characteristics, such as aligned porosity, high elasticity, scaffold stiffness, surface energy, and excellent shear behavior. In addition, its biocompatibility supplies Schwann cells with an adhesive, proliferative, and angiogenic interface, as is reflected by higher expression of functional proteins including nerve growth factor (NGF) and vascular endothelial growth factor (VEGF). In vivo mechanical stimuli by treadmill practice contribute to the comprehensive reparative therapy. The piezoelectric conduit accelerates nerve conducting velocity, promotes axonal remyelination, and restores motor function by recovering endplate muscles. Moreover, the piezoelectric nanogenerator scaffold creates biomimetic electrically conductive microenvironment without causing noticeable toxicity to functioning organs and improves peripheral nerve restoration by the multifunctional characteristics. Therefore, the mechano‐informed biomimetic piezoelectric scaffold may have enormous potential in the neuroengineering for regenerative medicine.
Zinc oxide scaffold facilitates electrical stimulation from external mechanical deformation. Under treadmill exercise used as mechanical stimulation, the zinc oxide‐loaded scaffold increases nerve conducting velocity, facilitates axon regrowth and myelin sheath thickening, and repairs endplate organs. It restores nutrient microenvironment without eliciting toxicity and promotes peripheral nerve restoration by multifunctional properties. The smart design provides potential in peripheral neuroengineering.
Antibiotic resistance genes (ARGs) in urban rivers are a serious public health concern in regions with poorly planned, rapid development. To gain insights into the predominant factors affecting the ...fate of ARGs in a highly polluted urban river in eastern China, a total of 285 ARGs, microbial communities, and 20 physicochemical parameters were analyzed for 17 sites. A total of 258 unique ARGs were detected using high-throughput qPCR, and the absolute abundance of total ARGs was positively correlated with total organic carbon and total dissolved nitrogen concentrations (
P
< 0.01). ARG abundance and diversity were greatly altered by microbial community structure. Variation partitioning analysis showed that the combined effects of multiple factors contributed to the profile and dissemination of ARGs, and variation of microbial communities was the major factor affecting the distribution of ARGs. The disparate distribution of some bacteria, including
Bacteroides
from mammalian gastrointestinal flora,
Burkholderia
from zoonotic infectious diseases, and
Zoogloea
from wastewater treatment, indicates that the urban river was strongly influenced by point-source pollution. Results imply that microbial community shifts caused by changes in water quality may lead to the spread of ARGs, and point-source pollution in urban rivers requires greater attention to control the transfer of ARGs between environmental bacteria and pathogens.
In this article, we investigate the connection between scalar curvature and first eigenfunctions via positive mass theorem for Brown-York mass. For compact manifolds with nice boundary, we show that ...a sharp inequality holds for first eigenfunctions when posing appropriate assumptions on scalar curvature and first eigenvalue. This inequality implies that for a compact n-dimensional manifold with boundary, its first eigenvalue is no less than n, if its scalar curvature is at least n(n-1) with appropriate boundary conditions posed, where equality holds if and only the manifold is isometric to the canonical upper hemisphere. As an application, we derive an estimate for the area of event horizon in a vacuum static space with positive cosmological constant, which reveals an interesting connection between the area of event horizon and Brown-York mass. This estimate generalizes a similar result of Shen Proc. Amer. Math. Soc. 125 (1997), pp. 901–905 for three dimensional vacuum static spaces and also improves the uniqueness result of de Sitter space-time due to Hizagi-Montiel-Raulot.
Peripheral nerve injury is a common clinical problem bringing heavy burden to patients, due to its high incidence and unsatisfactory treatment. Nerve guidance conduit (NGC) is a promising scaffold ...for peripheral nerve repair, and bioactive agents are applied for great functional recovery. Melatonin (MLT) and Fe3O4 magnetic nanoparticles (Fe3O4‐MNPs) are proven to inhibit oxidative stress, inflammation, and induce nerve regeneration. Herein, a multilayered composite NGC loaded with MLT and Fe3O4‐MNPs is designed for sequential and sustainable drug release, creating an appropriate microenvironment for nerve regeneration. The composite scaffold shows sufficient mechanical strength and biocompatibility in vitro, and evidently promotes morphological, functional, and electrophysiological recovery of regenerated sciatic nerves in vivo. This work proves that the multilayered conduits show great prospect in the long‐term nerve defects treatment due to easy manufacture and desired efficacy.
A multilayered composite scaffold loaded with melatonin (MLT) and Fe3O4‐MNPs is fabricated by electrospinning, which possesses good biocompatibility and proper stiffness. MLT inhibits oxidative stress and inflammation, while Fe3O4‐MNPs induces neurite regrowth. Sequential and sustainable release of bioactive agents provides an appropriate microenvironment for the long‐term treatment of nerve transections, showing great performance in nerve regeneration and functional recovery.
Magnetic multilayer devices that exploit magnetoresistance are the backbone of magnetic sensing and data storage technologies. Here, we report multiple-spin-filter magnetic tunnel junctions (sf-MTJs) ...based on van der Waals (vdW) heterostructures in which atomically thin chromium triiodide (CrI
) acts as a spin-filter tunnel barrier sandwiched between graphene contacts. We demonstrate tunneling magnetoresistance that is drastically enhanced with increasing CrI
layer thickness, reaching a record 19,000% for magnetic multilayer structures using four-layer sf-MTJs at low temperatures. Using magnetic circular dichroism measurements, we attribute these effects to the intrinsic layer-by-layer antiferromagnetic ordering of the atomically thin CrI
Our work reveals the possibility to push magnetic information storage to the atomically thin limit and highlights CrI
as a superlative magnetic tunnel barrier for vdW heterostructure spintronic devices.
In December, 2019, a pneumonia associated with the 2019 novel coronavirus (2019-nCoV) emerged in Wuhan, China. We aimed to further clarify the epidemiological and clinical characteristics of ...2019-nCoV pneumonia.
In this retrospective, single-centre study, we included all confirmed cases of 2019-nCoV in Wuhan Jinyintan Hospital from Jan 1 to Jan 20, 2020. Cases were confirmed by real-time RT-PCR and were analysed for epidemiological, demographic, clinical, and radiological features and laboratory data. Outcomes were followed up until Jan 25, 2020.
Of the 99 patients with 2019-nCoV pneumonia, 49 (49%) had a history of exposure to the Huanan seafood market. The average age of the patients was 55·5 years (SD 13·1), including 67 men and 32 women. 2019-nCoV was detected in all patients by real-time RT-PCR. 50 (51%) patients had chronic diseases. Patients had clinical manifestations of fever (82 83% patients), cough (81 82% patients), shortness of breath (31 31% patients), muscle ache (11 11% patients), confusion (nine 9% patients), headache (eight 8% patients), sore throat (five 5% patients), rhinorrhoea (four 4% patients), chest pain (two 2% patients), diarrhoea (two 2% patients), and nausea and vomiting (one 1% patient). According to imaging examination, 74 (75%) patients showed bilateral pneumonia, 14 (14%) patients showed multiple mottling and ground-glass opacity, and one (1%) patient had pneumothorax. 17 (17%) patients developed acute respiratory distress syndrome and, among them, 11 (11%) patients worsened in a short period of time and died of multiple organ failure.
The 2019-nCoV infection was of clustering onset, is more likely to affect older males with comorbidities, and can result in severe and even fatal respiratory diseases such as acute respiratory distress syndrome. In general, characteristics of patients who died were in line with the MuLBSTA score, an early warning model for predicting mortality in viral pneumonia. Further investigation is needed to explore the applicability of the MuLBSTA score in predicting the risk of mortality in 2019-nCoV infection.
National Key R&D Program of China.
In this paper, a novel node-based explicit smoothed particle finite element method (SPFEM), on the basis of the particle finite element method (PFEM) framework, is utilized to evaluate the stability ...of slopes and to simulate the post-failure behavior of soil. The main advantage of SPFEM in slope stability analysis lies in its capabilities to consider the whole dynamic failure process of slope and to simulate large deformation and post-failure of soils. For the stability analysis of a cohesive soil slope, the shear strength reduction technique with a kinetic energy-based criterion for distinguishing slope failure is adopted to obtain the factor of safety (FOS) of a slope, and the FOS is compared with that obtained by the classical FEM and LEM approaches for further validation. Then, the dynamic failure process of a non-cohesive granular material slope is simulated using Drucker-Prager constitutive model. The influence of friction resistance of granular material, as well as the repose angle of slope after failure, is discussed. Finally, the progressive failure behavior of a long clayey slope is modeled using SPFEM in conjunction with a strain-softening Tresca constitutive model. The retrogressive failure behavior of a long clayey slope is analyzed.
70 years ago, it was put forward that the diseased liver was not a favorable soil for metastatic tumor cells. In addition, a few studies have demonstrated that rare occurrence of colorectal liver ...metastases among patients with fatty liver, cirrhosis or chronic hepatitis B and C virus infection. We performed a meta-analysis to verify the association between the incidences of colorectal liver metastases with chronically diseased livers.
Relevant studies were identified by a search of electronic database PubMed, Cochrane Library, OVID, Web of Science and CNKI (up to February 24, 2014). Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using random- or fixed-effect models when appropriate. Meta-analysis and publication bias (Bgger's test) was evaluated with STATA 12.0.
A total of 10,349 colorectal cancer patients from 10 studies were included. The meta-analysis result showed there was a significant difference in the incidences of colorectal liver metastases between patients with normal and chronically diseased livers (OR = 0.32; 95% CI 95%: 0.26-0.38, P = 0.000 fixed-effects model). The result of Begg's test (Pr>|z| = 0.089; P>0.05) revealed no publication bias.
The results of this meta-analysis demonstrated that patients with chronically diseased livers had significantly lower incidences of colorectal liver metastases than those with normal livers.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The treatment of postoperative infection caused by multidrug‐resistant bacteria, such as methicillin‐resistant Staphylococcus aureus (MRSA), has become an intractable clinical challenge owing to its ...low therapeutic efficacy and high risk of recurrence. Apart from imperfect antibacterial therapies, induction of insufficient immunogenicity, required for the successful clearance of a pathogen, may also contribute to the problem. Herein, an ultra‐micro photosensitizer, AgB nanodots, using photothermal therapy, photodynamic therapy, and Ag+ ion sterilization, are utilized to efficiently clear invading MRSA both in vitro and in vivo. AgB nanodots are also found to upregulate host immunogenicity in a murine model and establish immunological memory by promoting the upregulated expression of danger signals that are commonly induced by stress‐related responses, including sudden temperature spikes or excess reactive oxygen production. These stimulations boost the antibacterial effects of macrophages, dendritic cells, T cells, or even memory B cells, which is usually defined as infection‐related immunogenic cell death. Hence, the proposed AgB nanodot strategy may offer a novel platform for the effective treatment of postoperative infection while providing a systematic immunotherapeutic strategy to combat persistent infections, thereby markedly reducing the incidence of recurrence following recovery from primary infections.
By eliciting infection‐related immunogenicity to achieve a higher level of active immunologic responses during acute phase infection and long‐term immunosurveillance, AgB nanodots under near‐infrared irradiation can demonstrate excellent antibacterial results through photothermal therapy, photodynamic therapy, and Ag+ ions. This strategy could solve the predicament remaining in postoperative methicillin‐resistant Staphylococcus aureus‐related infection and prevent recurrence.
Non-Ionic surfactant based vesicles, also known as niosomes, have attracted much attention in pharmaceutical fields due to their excellent behavior in encapsulating both hydrophilic and hydrophobic ...agents. In recent years, it has been discovered that these vesicles can improve the bioavailability of drugs, and may function as a new strategy for delivering several typical of therapeutic agents, such as chemical drugs, protein drugs and gene materials with low toxicity and desired targeting efficiency. Compared with liposomes, niosomes are much more stable during the formulation process and storage. The required pharmacokinetic properties can be achieved by optimizing components or by surface modification. This novel delivery system is also easy to prepare and scale up with low production costs. In this paper, we summarize the structure, components, formulation methods, quality control of niosome and its applications in chemical drugs, protein drugs and gene delivery.
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