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The human radial artery pulse carries a rich array of biomedical information. Accurate detection of pulse signal waveform and the identification of the corresponding pulse condition are helpful in understanding the health status of the human body. In the process of pulse detection, there are some problems, such as inaccurate location of radial artery key points, poor signal noise reduction effect and low accuracy of pulse recognition. In this system, the pulse signal waveform is collected by the main control circuit and the new piezoelectric sensor array combined with the wearable wristband, creating the hardware circuit. The key points of radial artery are located by an adaptive pulse finding algorithm. The pulse signal is denoised by wavelet transform, iterative sliding window and prediction reconstruction algorithm. The slippery pulse and the normal pulse are recognized by feature extraction and classification algorithm, so as to analyze the health status of the human body. The system has accurate pulse positioning, good noise reduction effect, and the accuracy of intelligent analysis is up to 98.4%, which can meet the needs of family health care.
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Dispositivos Eletrônicos Vestíveis , Punho , Humanos , Frequência Cardíaca , Artéria Radial , Sinais Vitais , Pulso ArterialRESUMO
BACKGROUND: Climate change may lead to emerging and re-emerging infectious diseases and pose public health challenges to human health and the already overloaded healthcare system. It is therefore important to review current knowledge and identify further directions in China, the largest developing country in the world. METHODS: A comprehensive literature review was conducted to examine the relationship between climate variability and infectious disease transmission in China in the new millennium. Literature was identified using the following MeSH terms and keywords: climatic variables [temperature, precipitation, rainfall, humidity, etc.] and infectious disease [viral, bacterial and parasitic diseases]. RESULTS: Fifty-eight articles published from January 1, 2000 to May 30, 2018 were included in the final analysis, including bacterial diarrhea, dengue, malaria, Japanese encephalitis, HFRS, HFMD, Schistosomiasis. Each 1⯰C rise may lead to 3.6%-14.8% increase in the incidence of bacillary dysentery disease in south China. A 1⯰C rise was corresponded to an increase of 1.8%-5.9% in the weekly notified HFMD cases in west China. Each 1⯰C rise of temperature, 1ï¼ rise in relative humidity and one hour rise in sunshine led to an increase of 0.90%, 3.99% and 0.68% in the monthly malaria cases, respectively. Climate change with the increased temperature and irregular patterns of rainfall may affect the pathogen reproduction rate, their spread and geographical distribution, change human behavior and influence the ecology of vectors, and increase the rate of disease transmission in different regions of China. CONCLUSION: Exploring relevant adaptation strategies and the health burden of climate change will assist public health authorities to develop an early warning system and protect China's population health, especially in the new 1.5 °C scenario of the newly released IPCC special report.
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Mudança Climática , Doenças Transmissíveis , Dengue , Exposição Ambiental , China , Humanos , Umidade , Incidência , TemperaturaRESUMO
BACKGROUND: Osteoporosis is a systemic skeletal disease with the high incidence, serious complications, financial burden, and heavily decrease in living quality. METHODS: Proliferation of osteoblast was tested by 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) method, alkaline phosphatase (ALP) activity of osteoblasts was tested by ALP REAGENT, Calcium level was determined by a colorimetric assay, mRNA expression of phosphoinositide-3 kinase (PI3K), 3-phosphoinositide-dependent protein kinase 1 (PDK1), Akt, Caspase-3, Caspase-7, Caspase-9, osteocalcin (OCN), Osterix and Runx2 of osteoblasts was tested by RNA preparation and quantitative reverse transcription polymerase chain reaction (RT-PCR), and protein expression of phospho-PI3K, phospho-PDK1 and phospho-Akt was measured by Western Blot analysis. RESULTS: In osteoporosis model rats, it found that mRNA expression of PI3K, PDK1 and Akt showed no changes while protein expression of phospho-PI3K, phospho-PDK1 and phospho-Akt in bone tissue was decreased dramatically. To further characterize the molecular mechanisms that regulate osteoporosis, we examined the contribution of the PI3K/Akt cell signaling pathway in cultured osteoblasts. It suggested that, the blockade of PI3K activation by LY294002, a specific inhibitor of the PI3K/Akt signaling pathway in osteoblasts, heavily inhibited cell proliferation, ALP activity, calcium accumulation, and mRNA expression of OCN, Osterix and Runx2. However, mRNA expression of Caspase-3 and Caspase-9 was promoted accordingly. CONCLUSION: The in vivo and in vitro studies indicated that the PI3K/Akt cell signaling pathway is involved in the inhibition of osteoporosis through promoting osteoblast proliferation, differentiation and bone formation.
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Modelos Animais de Doenças , Osteoblastos/metabolismo , Osteoporose/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Animais , Apoptose , Western Blotting , Cálcio/metabolismo , Proliferação de Células , Células Cultivadas , Feminino , Osteoblastos/citologia , Osteoporose/etiologia , Osteoporose/patologia , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Ligante RANK/metabolismo , RNA Mensageiro/genética , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
BACKGROUND: Osteoarticular tuberculosis (TB) is a common severe form of extrapulmonary tuberculosis. Early di- agnosis and treatment can decrease the deformity of spine and limbs and joint dysfunction. METHODS: We compared and evaluated two commercially available rapid test kits based on the ELISPOT assay for the diagnosis of osteoarticular disease. RESULTS: The diagnostic sensitivity and specificity of the FS-SPOT assay (50.0% and 85.7%) were similar to those of the T-SPOT-TB assay (45.5% and 81.0%). When the two test wells in the T-SPOT-TB assay were both positive, the test wells in FS-SPOT assay were usually positive with the number of SFCs exceeding those in the negative control wells by more than 30. The sensitivities, specificities, PPV, NPV, and agreement of FS-SPOT assay results in 99 TB cases and 54 non-TB disease cases were 55.6%, 83.3%, 84.7%, 52.9%, and 66.0%, respectively. SFC counts from test wells in the TB group were significantly higher than those from the non-TB group (p < 0.001). CONCLUSIONS: Higher numbers of SFCs in the ELISPOT assay suggest higher risk of active TB. ELISPOT may be a diagnostic aide for active osteoarticular TB.
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ELISPOT , Testes de Liberação de Interferon-gama , Interferon gama/sangue , Leucócitos Mononucleares/imunologia , Tuberculose Osteoarticular/diagnóstico , Adulto , Biomarcadores/sangue , Células Cultivadas , Feminino , Humanos , Leucócitos Mononucleares/microbiologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Kit de Reagentes para Diagnóstico , Reprodutibilidade dos Testes , Estudos Retrospectivos , Tuberculose Osteoarticular/sangue , Tuberculose Osteoarticular/imunologia , Tuberculose Osteoarticular/microbiologiaRESUMO
The pumped storage power station (PSPS) is an important measure to achieve the strategic goal of "dual carbon". As one of the preferred types for the upper reservoir dams of PSPSs, the concrete-faced rockfill dam (CFRD) often has a dam foundation on a steep transverse slop and is prone to produce slip deformation along the slope, resulting in poor anti-sliding stability of the dam slope. It is dangerous for the operation safety of PSPSs. Therefore, the slip deformation of CFRDs on dam foundations with large dip angles is investigated. The mechanism for the initiation of slip deformation is revealed. The design measures of physical mechanic and geometric structure are proposed to reduce slip deformation. The results show that the larger sliding forces and smaller anti-sliding forces are the fundamental reasons that CFRDs on dam foundations with large dip angles are prone to produce slip deformation. The larger the dip angle of the dam foundation, the larger the slip deformation of the dam body and face slab, and the smaller the safety factor of the dam slope. When the dip angle of the dam foundation is greater than 15°, the safety factor of the dam slope is less than the minimum value of 1.5 required by codes. The addition of pressure slopes can effectively reduce the slip deformation of the dam body or face slab and significantly improve the anti-sliding stability of the dam slope. When the height or width of the pressure slope platform is greater and the cohesion or internal friction angle of the pressure slope is larger, the slip deformations of the dam body and face slab are smaller, and the safety factor of the dam slope is greater. It is recommended that the height and width of the pressure slope platform be 1/2 times the maximum height of the main dam, and the density (cohesion and internal friction angle) of the pressure slope be equivalent to that of the main dam's rockfill material. The research results can provide theoretical and technical support for the design and construction of CFRDs for the upper reservoir of PSPSs.
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Few reports have focused on using particle electrodes with polar adsorbent properties in heterogeneous electro-Fenton (EF) system to improve the degradation of hydrophilic organic pollutants (HLOPs). In this study, a hydrophilic electrode Sn-Sb/AS was prepared by supporting metals Sn and Sb on alum sludge (AS), which can effectively degrade 91.68%, 92.54%, 89.62%, and 96.24% of the four types of HLOPs, chlorpyrifos (CPF), atrazine (ATZ), diuron (DIU), and glyphosate (PMG), respectively, within 40 min. The mineralization rates were 82.37%, 78.93%, 73.98%, and 85.65% for CPF, ATZ, DIU, and PMG, respectively. Based on the analysis of Electron Paramagnetic Resonance test, quenching test, and identified anthracene endoperoxide, the degradation at the cathode was attributed to non-radical oxidation via interaction with 1O2. In contrast, the anodic oxidation occurred via direct electron transfer at the anode and/or oxidation via interaction with adsorbed â¢OH (â¢OHads) around the particle electrodes. Furthermore, the reaction sites were calculated by Density functional theory (DFT) and Fukui function, corresponding to the electrophilic attack (fA-) of 1O2 and anodic direct oxidation, besides, the radical attack (fA0) of â¢OH(ads). Herein, this study proposes a targeted elimination strategy for HLOPs in wastewater treatment using particle electrodes with polar adsorbent properties in EF system.
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Synergistic mild photothermal/nanozyme therapy with outstanding hyperthermia performance and excellent multienzyme properties is highly needed for osteosarcoma treatment. Herein, we have developed efficient single-atom nanozymes (SANs) consisting of Mn sites atomically dispersed on nitrogen-doped carbon nanosheets (denoted as Mn-SANs) for synergistic mild photothermal/multienzymatic therapy against osteosarcoma. Benefiting from their black N-doped carbon nanosheet matrices, Mn-SANs showed an excellent NIR-II-triggered photothermal effect. On the other hand, Mn-SANs with atomically dispersed Mn sites have outstanding multienzyme activities. Mn-SANs can catalyze endogenous H2O2 in osteosarcoma into O2 by catalase (CAT)-like activity, which can effectively ease osteosarcoma hypoxia and trigger the oxidase (OXD)-like catalysis that converts O2 to the cytotoxic superoxide anion radical (â¢O2-). At the same time, Mn-SANs can also mimic glutathione oxidase (GSHOx) to effectively consume the antioxidant glutathione (GSH) in osteosarcoma and inhibit intracellular glutathione peroxidase 4 (GPX4) expression. Such intratumoral â¢O2- production, GSH depletion, and GPX4 inactivation mediated by Mn-SANs can create a large accumulation of lipid peroxides (LPO) and â¢O2-, leading to oxidative stress and disrupting the redox homeostasis in osteosarcoma cells, which can ultimately induce osteosarcoma cell death. More importantly, heat shock proteins (HSPs) can be significantly destroyed via Mn-SAN-mediated plentiful LPO and â¢O2- generation, thus effectively impairing osteosarcoma cells resistant to mild photothermal therapy. Overall, through the cooperative effect of chemical processes (boosting â¢O2-, consuming GSH, and enhancing LPO) and biological processes (inactivating GPX4 and hindering HSPs), collaborative mild photothermal/multienzymatic therapy mediated by Mn-SANs is a promising strategy for efficient osteosarcoma treatment.
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OBJECTIVE: To introduce a new animal model of graded mechanical primary brainstem injury (BSI). METHODS: Altogether 45 rabbits were subjected to BSI by type II biological impact machine designed by the Third Military Medical University. The animals were divided into 4 experimental groups (n equal to 10) and 1 control group (n equal to 5) according to different magnitudes of impact pressure imposed on the occipital nodule: Group 1, 500-520 kPa; Group 2, 520-540 kPa; Group 3, 540-560 kPa; Group 4, 560-580 kPa and Group 5, 0 kPa with 20 kPa increase in each grade. The impact depth was a constant 0.5 cm. After injury, the clinical symptoms and signs as well as pathological changes were observed. RESULTS: Rabbits in Group 1 revealed mild physiological reaction of BSI. They had localized cerebral contusion with punctate hemorrhage and subarachnoid hemorrhage (SAH) was limited to the peripheral tissues at the impact area. In Group 2, obvious physiological reaction was observed. Local pathological lesions reached the superficial layer of brainstem tissues; focal hemorrhage and girdle-shaped SAH in basilar pon were observed under microscope. In Group 3, BSI was more severe with a long respiratory depression. Pathological lesions reached the inner portion of brainstem with massive hemorrhage and the whole brainstem was wrapped by subarachnoid hematoma. In Group 4, most rabbits died due to severe BSI. Pathological lesions deepened to the central brainstem with wide pathological change, rapture of the medulla oblongata central canal. Group 5 was the control group, with normal brainstem structure and no lesion observed. CONCLUSION: This model successfully simulates different levels of brainstem mechanical injury and clearly shows the subsequent pathological changes following injury. It takes two external parameters (impact pressure and depth) and has a similar injury mechanism to clinical accelerating BSI. Moreover it is reproducible and stable, thus being be- neficial for exploring pathophysiological mechanism, diagnosis and forensic identification of various degrees of BSI.
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Tronco Encefálico/lesões , Modelos Animais de Doenças , Animais , Pressão , CoelhosRESUMO
OBJECTIVE: To compare the outcomes of anterior verus posterior instrumentation under different surgical procedures in the surgical management of thoracolumbar spinal tuberculosis (TB). METHODS: Between January 2004 and December 2009, 241 adult patients with thoracolumbar spinal TB underwent radical debridement and strut grafting plus anterior or posterior instrumentation in single-stage or two-stages. The mean age was 39 years (range: 16 - 67). The mean follow-up period for 189 patients was 37 months (range: 22 - 72). Among them, 157 cases underwent > 3 weeks of chemotherapeutic regimen of isoniazid, rifampin, pyrazinamide and ethambutol and the remaining 32 were operated for neurological impairment after 6-18 h with the same chemotherapeutic regimen. Except for 8 patients with skip lesions undergoing hybrid anteroposterior instrumentation, anterior instrumentation was utilized in 74 patients (Group A) and posterior instrumentation in 107 patients (Group B). RESULTS: In both groups, local symptoms of all patients were relieved significantly 1-3 weeks postoperatively. And 10/14 cases (71%) in Group A and 14/19 cases (74%) in Group B with neurological deficits had excellent or good clinical outcomes (P > 0.05). The levels of erythrocyte sedimentation rates (ESR) returned from 43.6 mm/h and 42.4 mm/h preoperatively to normal at 8-12 weeks postoperatively. Kyphosis degrees were corrected by a mean of 11.5° in Group A and 12.6° in Group B (P < 0.01). The correction loss was 6.8° in Group A and 6.1° in Group B at the last follow-up (P < 0.01). Fusion rates of the grafting bone were 92.5% and 91.8% respectively at the final follow-up (P > 0.05). Severe complications did not occur. CONCLUSION: Either anterior or posterior instrumentation can obtain good results in correction and maintenance of deformity, clearance of foci, decompression of spinal cord and pain relief in the treatment of thoracolumbar spinal TB as long as the surgical indications are properly selected. Posterior instrumentation may be superior to anterior instrumentation in the correction and maintenance of deformity.
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Fixação Interna de Fraturas/métodos , Vértebras Lombares , Vértebras Torácicas , Tuberculose da Coluna Vertebral/cirurgia , Adolescente , Adulto , Idoso , Feminino , Fixação Interna de Fraturas/instrumentação , Humanos , Fixadores Internos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto JovemRESUMO
Lung cancer is the most common and fatal malignant tumor in the world. The tumor microenvironment (TME) is closely related to the occurrence and development of lung cancer, in which the inflammatory microenvironment plays an important role. Inflammatory cells and inflammatory factors in the tumor inflammatory microenvironment promote the activation of the NF-κB and STAT3 inflammatory pathways and the occurrence, development, and metastasis of lung cancer by promoting immune escape, tumor angiogenesis, epithelial-mesenchymal transition, apoptosis, and other mechanisms. Clinical and epidemiological studies have also shown a strong relationship among chronic infection, inflammation, inflammatory microenvironment, and lung cancer. The relationship between inflammation and lung cancer can be better understood through the gradual understanding of the tumor inflammatory microenvironment, which is advantageous to find more therapeutic targets for lung cancer.
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OBJECTIVE: To evaluate the mid- or long-term clinical results and the factors that influence the outcomes of prosthetic disc nucleus (PDN) replacement in the treatment of lumbar disc disease. METHODS: Thirty-four patients who underwent the PDN replacement from March 2002 to October 2003 were followed for an average of 52.6 months (range from 48 to 66 months). Twenty patients were discogenic low back pain, 14 patients were lumbar disc herniation. The follow-up results were evaluated by using the Oswestry disability index (ODI) and the visual analogue scales (VAS) through direct examinations and questionnaires. ODI was 58.4% preoperatively, and VAS was 7.4. Radiography was also used to measure the range of motion (ROM) and disc height of the operative segment, and findings were compared with those on preoperative radiographs. RESULTS: Twelve months after operation, a significant proportion of patients recovered from low back pain or leg pain, ODI decreased to averaged 18.2%. VAS decreased to 1.8, the average increase of the postoperative disc height was 17.6%, ROM was 9.2 degrees. At the final followup, all patients with deteriorated leg radicular symptoms improved, ODI increased from 18.2% 12 months after operation to averaged 31.2%. Low back pain became more serious in 18 patients. VAS increased from 1.8 to 3.1, the average decrease of the postoperative to preoperative disc height was 13.5%, ROM decreased to 6.8 degrees. The rate of degeneration or breakages of the end plates was 64.7% (22/34), implant device migrations were observed in 25 patients. CONCLUSIONS: The mid- or long-term outcome of PDN replacement in the treatment of degenerative lumbar disc disease is not as encouraging as that of the short-term follow-up. It is neither effective in term of restoration of the intervertebral disc height nor increase of the ROM of the operative segment, complication rates are significantly higher, and inferior results are to be expected. The selection of suitable surgical candidates and determination of valid indications for operative treatment are very important.
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Artroplastia de Substituição , Disco Intervertebral , Vértebras Lombares , Adulto , Feminino , Seguimentos , Humanos , Disco Intervertebral/cirurgia , Deslocamento do Disco Intervertebral/cirurgia , Prótese Articular , Dor Lombar/etiologia , Dor Lombar/cirurgia , Vértebras Lombares/cirurgia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Epigallocatechin3gallate (EGCG) is a polyphenolic compound extracted and isolated from green tea, which has a variety of important biological activities in vitro and in vivo, including antitumor, antioxidation, antiinflammation and lowering blood pressure. The aim of the present study was to investigate the protective effect of EGCG against secondary osteoporosis in a mouse model via the Wnt/ßcatenin signaling pathway. Reverse transcriptionquantitative polymerase chain reaction (RTqPCR) and western blotting were used to analyze runtrelated transcription factor 2 and osterix mRNA expression, and the protein expression of cyclin D1, Wnt and ßcatenin, and suppressed peroxisome proliferatoractivated receptor γ protein expression. The protective effect of EGCG against secondary osteoporosis was examined and its potential mechanism was analyzed. Treatment with EGCG significantly decreased serum calcium, urinary calcium, body weight and body fat, and increased leptin levels in mice with secondary osteoporosis. In addition, EGCG treatment significantly inhibited the structure score of articular cartilage and cancellous bone in proximal tibia metaphysis in mice with secondary osteoporosis. Treatment also significantly decreased alkaline phosphatase activity, runtrelated transcription factor 2 and osterix mRNA expression. EGCG also significantly induced the protein expression of cyclin D1, Wnt and ßcatenin, and suppressed peroxisome proliferatoractivated receptor γ protein expression in mice with secondary osteoporosis. Taken together, these results suggest that EGCG may be a possible new drug in clinical settings.
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Catequina/análogos & derivados , Proliferação de Células/efeitos dos fármacos , Osteoporose/tratamento farmacológico , Chá/química , Via de Sinalização Wnt/efeitos dos fármacos , Animais , Cálcio/sangue , Cálcio/urina , Cartilagem/efeitos dos fármacos , Catequina/administração & dosagem , Catequina/química , Ciclina D1/genética , Modelos Animais de Doenças , Humanos , Camundongos , Osteoporose/sangue , Osteoporose/genética , Osteoporose/patologia , PPAR gama/genética , beta Catenina/genéticaRESUMO
OBJECTIVE: To investigate perioperative features and results of surgical treatment of spinal tuberculosis in aged. METHODS: Review the clinical data of 36 aged with spinal tuberculosis from May 1998 to June 2005 retrospectively. The average age was 70.2 years. The sites of infection included 3 cervical, 9 thoracic, 13 thoracolumbar and 11 lumbar. 28 patients suffered 1 or more complications at least and among of them, there were 18 patients have cerebral or heart vascular disease, 16 patients have diabetes mellitus. Before operation, all patients consulted with internal stuff for the proper treatment of concomitant disease. The surgical procedures include: CT guided percutaneous catheter drainage in 3 patients, anterior debridement and bony grafting with anterior instrumentation fixation in 12 patients, anterior debridement and bony grafting with posterior fixation in 5 patients, posterolateral costotransversectomy debridement and interbody fusion with posterior fixation in 7 patients, posterior debridement and posterior fixation in 9 patients. The mean followed-up period was 3 years and 10 months (from 1.5 to 6 years). RESULTS: One died at two week after the operation. Tuberculous infection was controlled in other patients and no recurrence. Two patients died because of myocardial infarction and cerebral hemorrhage respectively at 1.5 and 2.5 years after operation. Bone fusion was achieved in 31 patients. The deformity was partial corrected at the final follow-up. Among 20 cases with neurologic deficit, 11 cases were completely recovered, 5 cases were partly improved. CONCLUSIONS: If the associated disorders and postoperative complications are properly handled, aged patients can endure surgical treatment for spinal tuberculosis. Instrumentation fixation provides adequate stability and promote recovery.
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Serviços de Saúde para Idosos , Tuberculose da Coluna Vertebral/cirurgia , Idoso , Idoso de 80 Anos ou mais , Transplante Ósseo , Desbridamento , Feminino , Seguimentos , Fixação Interna de Fraturas , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Estudos Retrospectivos , Fusão Vertebral , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/cirurgia , Resultado do TratamentoRESUMO
The purpose of this study is to characterize the stress relax properties of PVA-H prosthetic nucleus via the four-parameter linear viscoelastic model and to analyze the influence of swelling ratio and initial PVA content upon the properties of dissipating compressive stress. The four-parameter linear viscoelastic model can simulate the viscoelastic property of prosthetic nucleus well (corr > 0.99) and be more effective than the three parameter linear viscoelastic model. From the parameters of this model we have obtained the following results: the prosthetic nucleus of higher water content can dissipate compressive stress more quickly than that of lower water content can do, but the quantity of stress relax can not be influenced by water content; the higher the initial PVA content,the slower and smaller the dissipation of compressive stress;the relax time of prosthetic nucleus is similar to that of human nucleus.
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Disco Intervertebral/fisiologia , Modelos Lineares , Modelos Biológicos , Álcool de Polivinil/química , Próteses e Implantes , Força Compressiva , Elasticidade , Viscosidade , Suporte de Carga/fisiologiaRESUMO
Ferromagnetic (L10 phase) CoPt alloy nanoparticles (NPs) with extremely high magnetocrystalline anisotropy are promising candidates for the next generation of ultrahigh-density data storage systems. It is a challenge to generate L10 CoPt NPs with high coercivity, controllable size, and a narrow size distribution. We report here the fabrication of L10 CoPt NPs by employing a heterobimetallic CoPt-containing polymer as a single-source precursor. The average size of the resulting L10 CoPt NPs is 3.4 nm with a reasonably narrow size standard deviation of 0.58 nm. The coercivity of L10 CoPt NPs is 0.54 T which is suitable for practical application. We also fabricated the L10 CoPt NP-based nanoline and nanodot arrays through nanoimprinting the polymer blend of CoPt-containing metallopolymer and polystyrene followed by pyrolysis. The successful transfer of the pre-defined patterns of the stamps onto the surface of the polymer blend implies that this material holds great application potential as a data storage medium.
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In this study the poly(vinyl alcohol)(PVA) hydrogel elastomer was prepared by freezing-thawing method. The influences of percentage of poly (vinyl alcohol) in hydrogel, pH of solution and swelling temperature upon the swelling characteristic of PVA-hydrogel prosthetic nucleus material were studied. Its micropores were observed using SEM, and the swelling dynamics was further discussed. The experimental results showed that the poly (vinyl alcohol) hydrogel was a kind of network with a lot of micropores, the pore size was related with the PVA content. The maximum swelling ratio decreases when the percentage of PVA in hydrogel, the pH of solution and the swelling temperature were enhanced. The swelling process was described by the equation of swelling dynamics equation. The swelling rate was greatly influenced by the PVA content, the pH of solution and the dimension of hydrogel sample.
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Disco Intervertebral , Álcool de Polivinil/química , Próteses e Implantes , Materiais Biocompatíveis/química , Hidrogéis , Concentração de Íons de Hidrogênio , Implantes Experimentais , Próteses e Implantes/normasRESUMO
In this paper we demonstrate a new type of quantum phase coherence (QPC), which is generated by the two-body interaction. This conclusion is based on quantum master equation analysis for the full counting statistics of electron transport through two parallel quantum-dots with antiparallel magnetic fluxes in order to eliminate the Aharonov-Bohm interference of either single-particle or non-interacting two-particle wave functions. The interacting two-particle QPC is realized by the flux-dependent oscillation of the zero-frequency cumulants including the shot noise and skewness with a characteristic period. The accurately quantized peaks of cumulant spectrum may have technical applications to probe the two-body Coulomb interaction.
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Molecular spintroinic device based on a single-molecule magnet is one of the ultimate goals of semiconductor nanofabrication technologies. It is thus necessary to understand the electron transport properties of a single-molecule magnet junction. Here we study the negative differential conductance and super-Poissonian shot noise properties of electron transport through a single-molecule magnet weakly coupled to two electrodes with either one or both of them being ferromagnetic. We predict that the negative differential conductance and super-Poissonian shot noise, which can be tuned by a gate voltage, depend sensitively on the spin polarization of the source and drain electrodes. In particular, the shot noise in the negative differential conductance region can be enhanced or decreased originating from the different formation mechanisms of negative differential conductance. The effective competition between fast and slow transport channels is responsible for the observed negative differential conductance and super-Poissonian shot noise. In addition, we further discuss the skewness and kurtosis properties of transport current in the super-Poissonian shot noise regions. Our findings suggest a tunable negative differential conductance molecular device, and the predicted properties of high-order current cumulants are very interesting for a better understanding of electron transport through single-molecule magnet junctions.
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Full counting statistics of electron transport is a powerful diagnostic tool for probing the nature of quantum transport beyond what is obtainable from the average current or conductance measurement alone. In particular, the non-Markovian dynamics of quantum dot molecule plays an important role in the nonequilibrium electron tunneling processes. It is thus necessary to understand the non-Markovian full counting statistics in a quantum dot molecule. Here we study the non-Markovian full counting statistics in two typical quantum dot molecules, namely, serially coupled and side-coupled double quantum dots with high quantum coherence in a certain parameter regime. We demonstrate that the non-Markovian effect manifests itself through the quantum coherence of the quantum dot molecule system, and has a significant impact on the full counting statistics in the high quantum-coherent quantum dot molecule system, which depends on the coupling of the quantum dot molecule system with the source and drain electrodes. The results indicated that the influence of the non-Markovian effect on the full counting statistics of electron transport, which should be considered in a high quantum-coherent quantum dot molecule system, can provide a better understanding of electron transport through quantum dot molecules.
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BACKGROUND: Detection of cervical high grade lesions in patients with atypical squamous cells of undetermined significance (ASCUS) is still a challenge. Our study tested the efficacy of the paired boxed gene 1 (PAX1) methylation analysis by methylation-sensitive high-resolution melting (MS-HRM) in the detection of high grade lesions in ASCUS and compared performance with the hybrid capture 2 (HC2) human papillomavirus (HPV) test. MATERIALS AND METHODS: A total of 463 consecutive ASCUS women from primary screening were selected. Their cervical scrapings were collected and assessed by PAX1 methylation analysis (MS-HRM) and high-risk HPV-DNA test (HC2). All patients with ASCUS were admitted to colposcopy and cervical biopsies. The Chi- square test was used to test the differences of PAX1 methylation or HPV infection between groups. RESULTS: The specificity, sensitivity, and accuracy for detecting CIN2 + lesions were: 95.6%, 82.4%, and 94.6%, respectively, for the PAX1 MS-HRM test; and 59.7%, 64.7%, and 60.0% for the HC2 HPV test. CONCLUSIONS: The PAX1 methylation analysis by MS-HRM demonstrated a better performance than the high-risk HPV-DNA test for the detection of high grade lesions (CIN2 +) in ASCUS cases. This approach could screen out the majority of low grade cases of ASCUS, and thus reduce the referral rate to colposcopy.