748 research outputs found

    Involvement of Human Papillomaviruses in Cervical Cancer

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    Human papillomaviruses (HPV) are the first viruses to have been acknowledged to prompt carcinogenesis, and they are linked with cancers of the uterine cervix, anogenital tumors, and head and neck malignancies. This paper examines the structure and primary genomic attributes of HPV and highlights the clinical participation of the primary HPV serotypes, focusing on the roles that HPV-16 and 18 play in carcinogenesis. The mechanisms that take place in the progression of cervical neoplasia are described. The oncogenic proteins E6 and E7 disrupt control of the cell cycle by their communication with p53 and retinoblastoma protein. Epidemiological factors, diagnostic tools, and management of the disease are examined in this manuscript, as are the vaccines currently marketed to protect against viral infection. We offer insights into ongoing research on the roles that oxidative stress and microRNAs play in cervical carcinogenesis since such studies may lead to novel methods of diagnosis and treatment. Several of these topics are surfacing as being critical for future study. One particular area of importance is the study of the mechanisms involved in the modulation of infection and cancer development at cervical sites. HPV-induced cancers may be vulnerable to immune therapy, offering the chance to treat advanced cervical disease. We propose that oxidative stress, mRNA, and the mechanisms of HPV infection will be critical points for HPV cancer research over the next decade

    The Development of Biomimetic Spherical Hydroxyapatite/Polyamide 66 Biocomposites as Bone Repair Materials

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    A novel biomedical material composed of spherical hydroxyapatite (s-HA) and polyamide 66 (PA) biocomposite (s-HA/PA) was prepared, and its composition, mechanical properties, and cytocompatibility were characterized and evaluated. The results showed that HA distributed uniformly in the s-HA/PA matrix. Strong molecule interactions and chemical bonds were presented between the s-HA and PA in the composites confirmed by IR and XRD. The composite had excellent compressive strength in the range between 95 and 132 MPa, close to that of natural bone. In vitro experiments showed the s-HA/PA composite could improve cell growth, proliferation, and differentiation. Therefore, the developed s-HA/PA composites in this study might be used for tissue engineering and bone repair

    A Hybrid Model Based on Support Vector Machine for Bus Travel-Time Prediction

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    Effective bus travel time prediction is essential in transit operation system. An improved support vector machine (SVM) is applied in this paper to predict bus travel time and then the efficiency of the improved SVM is checked. The improved SVM is the combination of traditional SVM, Grubbs’ test method and an adaptive algorithm for bus travel-time prediction. Since error data exists in the collected data, Grubbs’ test method is used for removing outliers from input data before applying the traditional SVM model. Besides, to decrease the influence of the historical data in different stages on the forecast result of the traditional SVM, an adaptive algorithm is adopted to dynamically decrease the forecast error. Finally, the proposed approach is tested with the data of No. 232 bus route in Shenyang. The results show that the improved SVM has good prediction accuracy and practicality

    Cell cycle-dependent phosphorylation of nucleophosmin and its potential regulation by peptidyl-prolyl cis/trans isomerase

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    Nucleophosmin (NPM) is a ubiquitously expressed phosphoprotein involved in many cellular processes. Phosphorylation is considered the major regulatory mechanism of the NPM protein, associated with diverse cellular events. In this study, we characterized the phosphorylation status of several physiological phosphorylation sites of NPM, especially the newly confirmed in vivo site threonine 95 (Thr95). NPM-Thr95 exhibits a transient and cell cycle-dependent phosphorylation state compared to several other in vivo phosphorylation sites examined, including Ser4, Thr199 and Thr234/Thr237. In addition, we characterized a functional interaction between NPM and the peptidyl-prolyl isomerase Pin1, which specifically bind to each other during mitosis. The demonstration of this binding represents a novel post-phosphorylation regulatory mechanism for NPM that has not been investigated before. Mutated Pin1 putative binding sites result in defected cell division and reduced number of mitotic cells, suggesting that post-phosphorylation is important for NPM in regulating cell cycle progression

    Mechanical properties and deformation mechanisms of nanocrystalline u-10mo alloys by molecular dynamics simulation

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    U-Mo alloys were considered to be the most promising candidates for high-density nuclear fuel. The uniaxial tensile behavior of nanocrystalline U-10Mo alloys with average grain sizes of 8–23 nm was systematically studied by molecular dynamics (MD) simulation, mainly focusing on the influence of average grain size on the mechanical properties and deformation mechanisms. The results show that Young’s modulus, yield strength and ultimate tensile strength follow as average grain size increases. During the deformation process, localized phase transitions were observed in samples. Grain boundary sliding and grain rotation, as well as twinning, dominated the deformation in the smaller and larger grain sizes samples, respectively. Increased grain size led to greater localized shear deformation, resulting in greater stress drop. Additionally, we elucidated the effects of temperature and strain rate on tensile behavior and found that lower temperatures and higher strain rates not only facilitated the twinning tendency but also favored the occurrence of phase transitions in samples. Results from this research could provide guidance for the design and optimization of U-10Mo alloys materials

    Quantum Rotational Cryptanalysis for Preimage Recovery of Round-Reduced Keccak

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    This paper considers the capability of 4-round Keccak-224/256/384/512 against the cryptanlysis involved by the quantum algorithm. In order to effectively find the corresponding rotational number for the rotational counterpart of preimage, we first establish a probabilistic algorithm based on the Grover search to guess a possible rotational number by using the fixed relations of bits pairs in some coordinates. This is committed to achieving that each iteration of searching the rotational counterparts contains only one run of 4-round Keccak variant applied for the verification, which can reduce the attack complexity in the quantum setting. Based on finding the rotational number under an acceptable randomness, we construct two attack models to focus on the recovery of preimage. In the first model, the Grover’s algorithm serves as finding out a rotational counterpart of the preimage. Through 64 attempts of checking the correct rotational number, the desired preimage can be obtained. In the second model, we abstract the finding of rotational counterparts into searching vertexes on a hypercube, and then, the SKW quantum algorithm is used to deal with the finding of the vertexes acted as rotational counterparts. Compared to the recent works in classical setting, we greatly reduce the attack complexity of preimage recovery. Furthermore, the first attack model is superior to the generic quantum preimage attack for 4-round Keccak-224/256/384/512, and the second model has slightly lower attack effect but more practicality on the 4-round Keccak-512/384, that is, the model is exponentially easier to implement in quantum circuit than both our first attack model and the generic quantum preimage attack

    Fitness of INTERGROWTH-21st birth weight standards for Chinese-ethnicity babies

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    OBJECTIVE: To determine the fitness of the INTERGROWTH-21st birth weight standards (INTERGROWTH21) for ethnic Chinese babies compared with a local reference (FOK2003). DESIGN: Population-based analysis of territory-wide birth data. SETTING: All public hospitals in Hong Kong. PARTICIPANTS: Live births between 24 and 42 complete weeks' gestation during 2006-2017. MAIN OUTCOME MEASURES: Babies' birth weight Z-scores were calculated using published methods. The two references were compared in three aspects: (1) the proportions of large-for-gestational-age (LGA) or small-for-gestational-age (SGA) infants, (2) the gestation-specific and sex-specific mean birth weight Z-scores and (3) the predictive power for SGA-related complications. RESULTS: 488 896 infants were included. Using INTERGROWTH21, among neonates born <33 weeks' gestation, the mean birth weight Z-scores per week were closer to zero (-0.2 to 0.05), while most of them were further from zero (0.06 to 0.34) after excluding infants with a high risk of abnormal intrauterine growth. Compared with FOK2003, INTERGROWTH21 classified smaller proportions of infants as SGA (8.3% vs 9.6%) and LGA (6.6% vs 7.9%), especially SGA among preterm infants (13.1% vs 17.0%). The area under the receiver operating characteristic curve for predicting SGA-related complications was greater with FOK2003 (0.674, 95% CI 0.670 to 0.677) than INTERGROWTH21 (0.658, 95% CI 0.655 to 0.661) (p<0.001). CONCLUSIONS: INTERGROWTH21 performed less well than FOK2003, a local reference for ethnic Chinese babies, especially in infants born <33 weeks' gestation. Although the differences are clinically small, both these references performed poorly for extremely preterm infants, and thus a more robust chart based on a larger sample of appropriately selected infants is needed
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