This paper is devoted to study the global attractors of the periodic initial value problem for Landau--Lifshitz--Bloch--Maxwell system. Fist we give the global existence of the smooth solution for this system. Then, we prove the existence of global attractors, the Hausdorff dimension and fractal dimension have been estimated.
In this paper, the nonlinear static analysis of Timoshenko nanobeams consisting of bi-directional functionally graded material (BFGM) with immovable ends is investigated. The scratching in the FG nanobeam mid-plane, is the source of nonlinearity of the bending problems . The non-local theory is used to investigate the nonlinear static deflection of nanobeam. In order to simplify the formulation, the problem formulas is derived according to the physical middle surface. The Hamilton principle is employed to determine governing partial differential equations as well as boundary conditions. Moreover, the differential quadrature method (DQM) and direct iterative method are applied to solve governing equations. Present results for nonlinear static deflection were compared with previously published results in order to validate the present formulation. The impacts of the nonlocal factors, beam length and material property gradient on the nonlinear static deflection of BFG nanobeams are investigated. It is observed that these parameters are vital in the value of the nonlinear static deflection of the BFG nanobeam.
Aim: To investigate the mean thrombocyte volume (MPV) in asymptomatic children infected with COVID-19. Methods: The study included 55 children infected with COVID-19 and 60 healthy children for the comparison of leukocyte and thrombocyte count, MPV, and serum C-reactive protein (CRP) levels. Demographic data and clinical findings of all the cases were recorded, including age, gender, weight, temperature, cough, shortness of breath and contact history. Results: The MPV values were determined to be statistically significantly high (p<0.001) and the lymphocyte values were significantly low (p:0.002) in the asymptomatic children infected with COVID-19 compared to the healthy control children. No difference was determined between the groups in respect of CRP level, leukocyte and thrombocyte counts (p>0.05). The optimal cutoff point for MPV was determined as 8.74 fl (Area under the curve-AUC:0.932) with 81.82% sensitivity and 95% specificity for the determination of children infected with COVID-19. A cutoff value of <2.12/mm3 for lymphocytes (AUC:0.670) was determined with 49.09% sensitivity and 86.67% specificity for the prediction of COVID-19. Based on the ROC analysis, the sensitivity and specificity of MPV was determined to be higher than that of lymphocyte levels. Conclusion: The results of this study that MPV levels are significantly high in asymptomatic children infected with COVID-19 demonstrate that this is an important predictive value and has better predictive capacity than lymphocyte values. The evaluation of MPV and lymphocyte levels together could increase diagnostic success in asymptomatic COVID-19 cases.
Ambrosia artemisiifolia and Ambrosia trifida are two species of very harmful and invasive plants of the same genus. However, it remains unclear why A. artemisiifolia is more widely distributed than A. trifida worldwide. Distribution and abundance of these two species were surveyed and measured from 2010 to 2017 in the Yili Valley, Xinjiang, China. Soil temperature and humidity, main companion species, the biological characteristics in farmland ecotone, residential area, roadside and grassland, and water demand of the two species were determined and studied from 2017 to 2018. The area occupied by A. artemisiifolia in the Yili Valley was more extensive than that of A. trifida, while the abundance of A. artemisiifolia in grassland was less than that of A. trifida at eight years after invasion. The interspecific competitive ability of two species were stronger than those of companion species in farmland ecotone, residential, and roadside. In addition, A. trifida had greater interspecific competitive ability than other plant species in grassland. The seed size and seed weight of A. trifida were five times or eight times those of A.artemisiifolia. When comparing the changes under simulated annual precipitation of 840 mm versus 280 mm, the seed yield per m2 of A. trifida decreased from 50,185 to 19, while that of A. artemisiifolia decreased from 15,579 to 530. The differences in the distribution of the two species are mainly due to differences in interspecific competitive ability, seed size, and water dependence. The two species have stronger interspecific competitive ability than that of companion species, but A. artemisiifolia has a smaller seed size and stronger drought tolerance, which allows A. artemisiifolia to spread farther than A. trifida. The reason for wider distribution of A. trifida in grassland is that A. trifida has stronger interspecific competitive ability than A. artemisiifolia under sufficient water.
Salts in the root zone have high spatial variability, changes rapidly and adversely affects soil quality and crop productivity. Rapid detection of electrical conductivity (EC) using visible-near infrared (Vis-NIR) and midinfrared (MIR) spectroscopy can alleviate the adverse effects on soil and plant, which through conventional method is time consuming. Soils were collected from the Indo-Gangetic plains and analyzed for EC using conventional, Vis-NIR, MIR spectroscopy and there was wide variation in EC measured by the conventional method. The spectral regions in 460-500 and 1890-1906 nm in the Vis-NIR region and 4200-4310, 5275-5280, 6660-6670, 7305-7310 and 8290-8300 nm in the MIR region were sensitive to detection of EC. Partial least square regression (PLSR) outperformed random forest regression (RF), support vector regression (SVR), and multivariate adaptive regression splines (MARS) both in Vis-NIR and MIR region during calibration. The ratio of performance deviation (RPD), coefficient of determination (R2) and root mean square error (RMSE) of the validation dataset were used to assess the prediction accuracy and the predictive performance of PLSR (2.44, 0.84, 0.21), RF (1.95, 0.81, 0.20), SVR (2.09, 0.78, 0.22) and MARS (1.81, 0.73, 0.27) models. PLSR model performed very well in the Vis-NIR range; however, in the MIR range, RF (1.43, 0.52, 0.20), followed by PLSR (1.40, 0.55, 0.35), performed better than SVR (1.39, 0.53, 0.35) and MARS (1.29, 0.44, 0.37). Vis-NIR spectroscopy with PLSR algorithm predicted EC better than MIR spectroscopy and would be the method of choice for rapid estimation and prediction of EC in the study region.
Severe COVID-19 is a multisystem inflammatory disorder and knowledge and experience with severe acute respiratory failure in infected patients has grown considerably since reports of the first few cases. Little is known about the effect of SARS-CoV-2 on the heart, and there has been a suggestion from published literature that fulminant cardiac failure with or without respiratory failure may occur several weeks following infection. A young man presented after a recent viral illness. He was found to be in severe cardiogenic shock and was implanted with an emergency biventricular assist device, which also incorporated an extracorporeal membrane oxygenator. He stabilised soon thereafter and despite an intracerebral haemorrhage, which resolved, and bleeding into the trachea following percutaneous tracheostomy, he survived to explant and was successfully stepped down to a rehabilitation unit on postoperative day 50. He tested positive for SARS-CoV-2 antibodies when the test became available on postoperative day 33. We envisage there will be many more such presentations of acute COVID-19-associated cardiogenic shock and we recommend clinicians consider this diagnosis when presented with an acutely unwell patient with an unclear diagnosis, following a viral illness. These patients should be discussed as early as possible with a transplant/mechanical circulatory support team.
Plants are exposed to a wide range of temperatures during their life cycle and need to continuously adapt. These adaptations need to deal with temperature changes on a daily and seasonal level and with temperatures affected by climate change, and need to take into account that different organs have different optimal temperature ranges. Increasing global temperatures impact crop performance, and several physiological and developmental responses to increased temperature have been described that allow to mitigate this. In this review, we assess various developmental, physiological and biochemical responses of crops to high temperature, focusing on knowledge gained from both monocots (e.g. wheat, barley, maize, rice) and dicots (e.g. soybean or tomato). We outline several outstanding questions where crop research can exploit knowledge from model plants, such as Arabidopsis thaliana, and we highlight that studying molecular mechanisms directly in relevant crops is essential.
Long-term experimental watershed studies have significantly influenced our global understanding of hydrological processes. The discovery and characterization of how stream water quantity and quality respond to a changing environment (e.g., land use change and acidic deposition) has only been possible due to the establishment of catchments devoted to long-term study. One such catchment is the Fernow Experimental Forest (FEF) located in the headwaters of the Appalachian Mountains in West Virginia, a region that provides essential freshwater ecosystem services to eastern and mid-western USA communities. Established in 1934, the FEF is among the earliest experimental watershed studies in the Eastern USA that continues to address emergent challenges to forest ecosystems, including climate change and other threats to forest health. This data note summarizes some of the seminal findings from more than 50 years of hydrologic research in the FEF. During the first few decades, research at the FEF focused on the relationship between forest management and hydrological processes – especially those related to the overall water balance. Later, research efforts included the examination of interactions between hydrology and soil erosion, biogeochemistry, N-saturation, and acid deposition. Hydro-climatologic and water quality datasets from long-term measurements and data from short-duration studies are publicly available to provide new insights and foster collaborations that will continue to advance our understanding of hydrology in forested headwater catchments. As a result of its rich history of research and abundance of long-term data, the FEF is uniquely positioned to continue to advance understanding of forest ecosystems in a time of unprecedented change.
Finite element simulations of bonded repair technology can greatly reduce the cost of repairing ageing and damaged aircraft structures. In this study, finite element simulation and analysis are performed for several bonded repair techniques of damaged aircraft structures with cracks. The simulations start from fatigue damage accumulation, crack initiation, crack repair, to fatigue crack re-initiation until structural failure. The effectiveness of bonded repair techniques is assessed by comparing the service lives of no repair, patch-bonded repair (live repair), stop-drill repair, and damage removal repair. It is found that the load attraction by repair patch can greatly sustain fatigue crack growth, leading to more than at least 2 times longer service life before the skin structure needs to be replaced. Damage removal bonded repair can further extend service life by more than 20 times comparing to no repair, benefiting from the fatigue damage tolerant service life extension. Along with the service life comparison, we also established a simulation framework that lays out the groundwork to perform aerostructure bonded repair effectiveness evaluation. The results demonstrate that finite element analysis can be efficiently used to simulate the various forms of bonded repairs and effectively evaluate fatigue crack growth and service life with structural damage. Such a rigorous simulation framework enables the future design of new repair techniques for aircraft structures.
Virus-like particle (VLP), a self-assembled multiprotein structure, can stimulate robust immune responses due to its structure similar to native virions that curries multiple copies of the target epitopes. Utilizing VLPs as vaccine platforms to present exogenous antigens is a promising and challenging approach in the vaccine development field. This study aims to investigate the potential of hepatitis E virus (HEV) truncated capsid as a VLP platform to present foreign antigens. The S and M domains of HEV capsid protein were selected as the optimal carrier (CaSM). The exogenous antigen Seq8 containing three neutralizing epitopes from three different foot-and-mouth disease virus (FMDV) strains was linked to the C-terminal of CaSM to construct a chimeric VLP (CaSM-Seq8). The construct was successfully expressed and purified. Morphological analysis showed that CaSM-Seq8 self-assembled into VLPs similar to CaSM VLP (~26 nm in diameter) but smaller than native HEV virions. Further, the thermal stability and the resistance to enzymatic proteolysis of Seq8 were enhanced when it was attached to CaSM carrier. The antigenicity analysis revealed a more robust reactivity against anti-FMDV antibodies when Seq8 was presented on the CaSM particles. Upon injection into mice, FMDV-specific IgGs induced by CaSM-Seq8 appeared earlier, increased faster, and maintained higher levels for a longer time than those induced by Seq8 alone or the inactivated FMDV vaccine. This study demonstrated the potential of utilizing HEV truncated capsid as an antigen-presenting platform for the development of chimeric VLP vaccines.
Background: Severe asthma exacerbation is an important comorbidity of the 2009 HIN1 pandemic [A(H1N1)pdm09] in asthmatic patients. However, the mechanisms underlying severe asthma exacerbation remain unknown. Using a mouse model of asthma, we evaluated airway hyperresponsiveness (AHR) in mice with A(H1N1)pdm09 infection and those with seasonal influenza for comparison. We also measured AHR in paediatric participants infected with A(H1N1)pdm09. Methods: BALB/c mice aged 6-8 weeks were sensitized and challenged with ovalbumin. Either mouse-adapted A(H1N1)pdm09, seasonal H1N1 virus (1×105 pfu/20 μL), or mock treatment as a control was administered intranasally. At 3, 7, and 10 days after infection, each group of mice was evaluated for AHR by methacholine challenge using an animal ventilator, flexiVent®. Lung samples were resected and observed using light microscopy to assess the degree of airway inflammation. AHRs in paediatric participants were defined as the provocative acetylcholine concentration causing a 20% reduction in FEV1.0 (PC20). Results: Airway resistance was significantly enhanced in A(H1N1)pdm09-infected asthmatic mice compared to that in seasonal H1N1-infected mice (p<0.001), peaking at 7 days post-infection and then becoming similar to control levels by 10 days post-infection. Histopathological examination of lung tissues showed more intense infiltration of inflammatory cells and severe tissue destruction in A(H1N1)pdm09-infected mice at 7 days post-infection than at 10 days post-infection. AHRs in the paediatric participants were temporarily increased, and alleviated by 3 months after discharge. Conclusions: Our results suggest that enhanced AHR could contribute to severe exacerbation in human asthmatic patients with A(H1N1)pdm09 infection.
Right ventricular (RV) pseudoaneurysm is very rare and is seen after penetrating chest trauma, cardiac surgery, infective endocarditis, myocardial infarction, syphilis, endomyocardial biopsy, lead extraction. Idiopathic right ventricular pseudoaneurysm is even rarer. They have varied presentations depending on the etiology. Diagnosis is usually made by echocardiography. Cardiac magnetic resonance imaging (CMR) helps in delineating the aneurysm and relationship with surrounding structures and helps in guiding the surgery. We hereby report a case of idiopathic right ventricular pseudoaneurysm presented with ventricular tachycardia (VT). Aneurysm was successfully treated by surgical excision. Patient was doing well on follow up with no further VT episodes.
Incurable breast cancer bone metastasis causes widespread bone loss, resulting in fragility, pain, increased fracture risk, and ultimately increased patient mortality. Increased mechanical signals in the skeleton are anabolic and protect against bone loss, and they may also do so during osteolytic bone metastasis. Skeletal mechanical signals include interdependent tissue deformations and interstitial fluid flow, but how metastatic tumor cells respond to each of these individual signals remains under-investigated, a barrier to translation to the clinic. To delineate their respective roles, we report computed estimates of the internal mechanical field of a bone-mimetic scaffold undergoing combinations of high and low compression and perfusion using multiphysics simulations. Simulations were conducted in advance of multi-modal loading bioreactor experiments with bone metastatic breast cancer cells to ensure that mechanical stimuli occurring internally were physiological and anabolic. Our results show that mechanical stimuli throughout the scaffold were within the anabolic range of bone cells in all loading configurations, were homogenously distributed throughout, and that combined high magnitude compression and perfusion synergized to produce the largest wall shear stresses within the scaffold. These simulations, when combined with experiments, will shed light on how increased mechanical loading in the skeleton may confer anti-tumorigenic effects during metastasis.
Introduction: The “crosstalk” (CST) ablation technique has been reported to reduce unnecessary ablation during cryoballoon (CB) ablation (CBA). Nevertheless, it is unclear which situations will necessitate the adoption of the technique. Methods and Results: The effect of the technique was analyzed in AF patients underwent CBA from July 2017 to February 2020. The balloon occlusion status and nadir temperature (NT) were compared, and all ablated PVs were categorized into three groups according to the necessity and effectiveness of the technique. Of 1082 superior PVs (SPVs), 16, 40, and 1026 were identified in the CST success group, CST failure group, and control group, respectively. The proportion of SPVs ablated with complete occlusion with CB was significantly higher in the CST success group (100%) than in the CST failure group (16.7%) or control group (49.4%) (CST success group vs. CST failure group, p<0.001; CST success group vs. control group, p<0.002). The proportion of SPVs ablated with NT ≤-46°C was higher in the CST success group (100%) than in the CST failure group (56.7%) (p<0.05). The CST ablation technique was always effective if CBA of the SPVs was performed with both complete occlusion and NT ≤-46°C and was almost always ineffective if it did not meet these two criteria (sensitivity, 100%; specificity, 93%). Conclusion: Successful CST ablation was highly predicted if complete PV occlusion and NT ≤-46°C during CBA of the SPVs were achieved, which could be useful when adopting the technique targeting inferior PVs to reduce unnecessary freezing during SPV isolation.
Tuberculosis (TB) is a re-emerging disease occurring worldwide and causing multi-billion-dollar loss and human death annually. The situation is worse in developing countries like Ethiopia, where lower knowledge, attitude, and practice (KAP) of the people is imminent. A questionnaire-based cross-sectional study was conducted to assess KAP of livestock ouners towards human and bovine Tuberculosis. A total of 349 study participants were addressed through face to face interview. Descriptive statistics and Pearson’s chi-squares analysis were used to observe the data and the association between outcome (KAP) and predictor variables. Out of the 349 respondents interviewed, 223 (63.9%) of them were males, while 126 (36.1%) were females. The KAP measuring interview indicated that almost all (97.4%) of the participants know human tuberculosis, while 84(24.1%) are aware of bovine tuberculosis cause and mode of transmission. Inhalation was reported as a common route of transmission for human TB (41.1%). In contrast, 50% of the respondent mentioned inhalation, contact, and ingestion of raw animal products as the main route of TB transmission from animal to human. Among those who have heard of bTB, only 56 (66.7%) of respondents consider bovine tuberculosis as a significant threat to public health. The study showed that there is a lower KAP on bovine TB among cattle owners. Therefore, community awareness promotion and health education on human and bovine TB should be operated under a “One Health” umbrella
In last decades, many alleviation measures were proposed in order to improve the life of fretting fatigue affected components. The aim of such palliatives is that to counteract the high stress gradients that arise near the contact surface. In such a context, the shot peening treatment is worth noting. Therefore, in the present paper, the fatigue life of shot-peened aluminium and titanium alloy specimens, subject to fretting fatigue under partial slip regime, is assessed by means of the Carpinteri et al. criterion for fretting fatigue. Firstly, according to the superposition principle, the relaxed residual stresses (due to the shot peening treatment) are combined with the stress components due to fretting fatigue loading. Then fretting fatigue assessment is performed. In such a context, a novel theoretical law for the relaxed residual stress field is here proposed, the implementation of which shows very promising results in terms of fatigue life estimation of the shot-peened specimens examined.