185 research outputs found
Induction of Changes Over time in the Rat Proximal Femur Following Ovariectomy: A Model with Clinical Implications
The menopause-related expansion of the proximal femoral marrow cavity is thought to have implications for the long-term cohesion of hip prostheses. This theory would be further strengthened if there was evidence to show that the expansion of the proximal femur marrow cavity takes place after the occurrence of a femoral neck fracture, which, it is often recommended, should be fixed with a hip prosthesis. But till now, the temporal relationship between those two osteoporotic-related changes has not been checked carefully. The objective of the current study was to examine the temporal relationship between the marrow cavity expansion of the proximal femur and the biomechanical deterioration of the femoral neck in a rat model. To do so, a cross-sectional study with multiple time points was carried out on 6-month old Sprague-Dawley rats, which were ovariectomized or sham-operated (as controls). The biomechanical properties of the femur neck and geometrical parameters of the femur shaft were evaluated at 0, 3, 6, 9, 12, 15, 18, and 21 weeks postoperatively, with special reference to the timescale of the observed changes. We found that the maximum load of the femoral neck in ovariectomized rats could bear decreased significantly compared, to that of controls, at 9 weeks postoperatively (p=0.03), while the marrow cavity of the proximal femur in ovariectomized rats turned out to be significantly enlarged at 15 weeks postoperatively (p=0.04). Conclusion: Our result demonstrated that the osteoporosis-related marrow-enlarged posterior led to the collapse of femoral neck strength. If the change in postmenopausal women is analogous to that in ovariectomized rats, the menopause-related marrow cavity expansion would be a risk factor for the longevity of hip prostheses.
Competing Fractional Quantum Hall and Electron Solid Phases in Graphene
We report experimental observation of the reentrant integer quantum Hall
effect in graphene, appearing in the N2 Landau level. Similar to
high-mobility GaAs/AlGaAs heterostructures, the effect is due to a competition
between incompressible fractional quantum Hall states, and electron solid
phases. The tunability of graphene allows us to measure the - phase
diagram of the electron-solid phase. The hierarchy of reentrant states suggest
spin and valley degrees of freedom play a role in determining the ground state
energy. We find that the melting temperature scales with magnetic field, and
construct a phase diagram of the electron liquid-solid transition
A comprehensive city-level final energy consumption dataset including renewable energy for China, 2005–2021
The role of China is increasingly pivotal in climate change mitigation, and the formulation of energy conservation and emission reduction policies requires city-level information. The effectiveness of national policy implementation is contingent upon the support and involvement of local governments. Accurate data on final energy consumption is vital to formulate and implement city-level energy transitions and energy conservation and emission reduction policies. However, there is a dearth of data sources pertaining to China’s city-level final energy consumption. To address these gaps, we developed computational modeling techniques along with top-down and downscaling methods to estimate China’s city-level final energy consumption. In this way, we compiled a final energy consumption inventory for 331 Chinese cities from 2005 to 2021, covering seven economic sectors, 30 fossil fuels, and four clean power sources. Moreover, we discussed the validity of the estimation results from multiple perspectives to enhance estimation accuracy. This dataset can be utilized for analysis in various cutting-edge research fields such as energy transition dynamics, transition risk management strategies, and policy formulation processes
A comprehensive city-level final energy consumption dataset including renewable energy for China, 2005–2021
The role of China is increasingly pivotal in climate change mitigation, and the formulation of energy conservation and emission reduction policies requires city-level information. The effectiveness of national policy implementation is contingent upon the support and involvement of local governments. Accurate data on final energy consumption is vital to formulate and implement city-level energy transitions and energy conservation and emission reduction policies. However, there is a dearth of data sources pertaining to China’s city-level final energy consumption. To address these gaps, we developed computational modeling techniques along with top-down and downscaling methods to estimate China’s city-level final energy consumption. In this way, we compiled a final energy consumption inventory for 331 Chinese cities from 2005 to 2021, covering seven economic sectors, 30 fossil fuels, and four clean power sources. Moreover, we discussed the validity of the estimation results from multiple perspectives to enhance estimation accuracy. This dataset can be utilized for analysis in various cutting-edge research fields such as energy transition dynamics, transition risk management strategies, and policy formulation processes
Competing Fractional Quantum Hall and Electron Solid Phases in Graphene
International audienceWe report experimental observation of the reentrant integer quantum Hall effect in graphene, appearing in the N=2 Landau level. Similar to high-mobility GaAs/AlGaAs heterostructures, the effect is due to a competition between incompressible fractional quantum Hall states, and electron solid phases. The tunability of graphene allows us to measure the B-T phase diagram of the electron solid phase. The hierarchy of reentrant states suggests spin and valley degrees of freedom play a role in determining the ground state energy. We find that the melting temperature scales with magnetic field, and construct a phase diagram of the electron liquid-solid transition
Neuroinflammation mediates noise-induced synaptic imbalance and tinnitus in rodent models
Hearing loss is a major risk factor for tinnitus, hyperacusis, and central auditory processing disorder. Although recent studies indicate that hearing loss causes neuroinflammation in the auditory pathway, the mechanisms underlying hearing loss-related pathologies are still poorly understood. We examined neuroinflammation in the auditory cortex following noise-induced hearing loss (NIHL) and its role in tinnitus in rodent models. Our results indicate that NIHL is associated with elevated expression of proinflammatory cytokines and microglial activation-two defining features of neuroinflammatory responses-in the primary auditory cortex (AI). Genetic knockout of tumor necrosis factor alpha (TNF-alpha) or pharmacologically blocking TNF-alpha expression prevented neuroinflammation and ameliorated the behavioral phenotype associated with tinnitus in mice with NIHL. Conversely, infusion of TNF-alpha into AI resulted in behavioral signs of tinnitus in both wild-type and TNF-alpha knockout mice with normal hearing. Pharmacological depletion of microglia also prevented tinnitus in mice with NIHL. At the synaptic level, the frequency of miniature excitatory synaptic currents (mEPSCs) increased and that of miniature inhibitory synaptic currents (mIPSCs) decreased in AI pyramidal neurons in animals with NIHL. This excitatory-to-inhibitory synaptic imbalance was completely prevented by pharmacological blockade of TNF-alpha expression. These results implicate neuroinflammation as a therapeutic target for treating tinnitus and other hearing loss-related disorders.National Institute of Health [DC009259, DC014335]; Department of Defense [W81XWH-15-1-0028, W81XWH-15-1-0356, W81XWH-15-1-0357]; Food and Health Bureau of Hong Kong Special Administrative Region Government [04150076]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Global metabolic responses of the lenok (Brachymystax lenok) to thermal stress
High temperature is a powerful stressor for fish living in natural and artificial environments, especially for cold water species. Understanding the impact of thermal stress on physiological processes of fish is crucial for better cultivation and fisheries management. However, the metabolic mechanism of cold water fish to thermal stress is still not completely clear. In this study, a NMR-based metabonomic strategy in combination with high throughput RNA-Seq was employed to investigate global metabolic changes of plasma and liver in a typical cold water fish species lenok (Brachymystax lenok) subjected to a sub-lethal high temperature. Our results showed that thermal stress caused multiple dynamic metabolic alterations of the lenok with prolonged stress, including repression of energy metabolism, shifts in lipid metabolism, alterations in amino acid metabolism, changes in choline and nucleotide metabolisms. Specifically, thermal stress induced an activation of glutamate metabolism, indicating that glutamate could be an important biomarker associated with thermal stress. Evidence from Hsp 70 gene expression, blood biochemistry and histology confirmed that high temperature exposure had negative effects on health of the lenok. These findings imply that thermal stress has a severe adverse effect on fish health and demonstrate that the integrated analyses combining NMR-based metabonomics and transcriptome strategy is a powerful approach to enhance our understanding of metabolic mechanisms of fish to thermal stress.</p
“No powers, man!”: A student perspective on designing university smart building interactions
Smart buildings offer an opportunity for better performance and enhanced experience by contextualising services and interactions to the needs and practices of occupants. Yet, this vision is limited by established approaches to building management, delivered top-down through professional facilities management teams, opening up an interaction-gap between occupants and the spaces they inhabit. To address the challenge of how smart buildings might be more inclusively managed, we present the results of a qualitative study with student occupants of a smart building, with design workshops including building walks and speculative futuring. We develop new understandings of how student occupants conceptualise and evaluate spaces as they experience them, and of how building management practices might evolve with new sociotechnical systems that better leverage occupant agency. Our findings point to important directions for HCI research in this nascent area, including the need for HBI (Human-Building Interaction) design to challenge entrenched roles in building management
Machine Learning for Prediction of Sudden Cardiac Death in Heart Failure Patients With Low Left Ventricular Ejection Fraction: Study Protocol for a Retrospective Multicentre Registry in China
Introduction: Left ventricular ejection fraction (LVEF) ≤35%, as current significant implantable cardioverter-defibrillator (ICD) indication for primary prevention of sudden cardiac death (SCD) in heart failure (HF) patients, has been widely recognised to be inefficient. Improvement of patient selection for low LVEF (≤35%) is needed to optimise deployment of ICD. Most of the existing prediction models are not appropriate to identify ICD candidates at high risk of SCD in HF patients with low LVEF. Compared with traditional statistical analysis, machine learning (ML) can employ computer algorithms to identify patterns in large datasets, analyse rules automatically and build both linear and non-linear models in order to make data-driven predictions. This study is aimed to develop and validate new models using ML to improve the prediction of SCD in HF patients with low LVEF. Methods and analysis: We will conduct a retroprospective, multicentre, observational registry of Chinese HF patients with low LVEF. The HF patients with LVEF ≤35% after optimised medication at least 3 months will be enrolled in this study. The primary endpoints are all-cause death and SCD. The secondary endpoints are malignant arrhythmia, sudden cardiac arrest, cardiopulmonary resuscitation and rehospitalisation due to HF. The baseline demographic, clinical, biological, electrophysiological, social and psychological variables will be collected. Both ML and traditional multivariable Cox proportional hazards regression models will be developed and compared in the prediction of SCD. Moreover, the ML model will be validated in a prospective study. Ethics and dissemination: The study protocol has been approved by the Ethics Committee of the First Affiliated Hospital of Nanjing Medical University (2017-SR-06). All results of this study will be published in international peer-reviewed journals and presented at relevant conferences
Benefits and harms of direct oral anticoagulation and low molecular weight heparin for thromboprophylaxis in patients undergoing non-cardiac surgery : systematic review and network meta-analysis of randomised trials
OBJECTIVE To systematically compare the effect of direct oral anticoagulants and low molecular weight heparin for thromboprophylaxis on the benefits and harms to patients undergoing non-cardiac surgery. DESIGN Systematic review and network meta-analysis of randomised controlled trials. DATA SOURCES Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL), up to August 2021. REVIEW METHODS Randomised controlled trials in adults undergoing non-cardiac surgery were selected, comparing low molecular weight heparin (prophylactic (low) or higher dose) with direct oral anticoagulants or with no active treatment. Main outcomes were symptomatic venous thromboembolism, symptomatic pulmonary embolism, and major bleeding. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used for network meta-analyses. Abstracts and full texts were screened independently in duplicate. Data were abstracted on study participants, interventions, and outcomes, and risk of bias was assessed independently in duplicate. Frequentist network meta-analysis with multivariate random effects models provided odds ratios with 95% confidence intervals, and GRADE (grading of recommendations, assessment, development, and evaluation) assessments indicated the certainty of the evidence. RESULTS 68 randomised controlled trials were included (51 orthopaedic, 10 general, four gynaecological, two thoracic, and one urological surgery), involving 45 445 patients. Low dose (odds ratio 0.33, 95% confidence interval 0.16 to 0.67) and high dose (0.19, 0.07 to 0.54) low molecular weight heparin, and direct oral anticoagulants (0.17, 0.07 to 0.41) reduced symptomatic venous thromboembolism compared with no active treatment, with absolute risk differences of 1-100 per 1000 patients, depending on baseline risks (certainty of evidence, moderate to high). None of the active agents reduced symptomatic pulmonary embolism (certainty of evidence, low to moderate). Direct oral anticoagulants and low molecular weight heparin were associated with a 2-3-fold increase in the odds of major bleeding compared with no active treatment (certainty of evidence, moderate to high), with absolute risk differences as high as 50 per 1000 in patients at high risk. Compared with low dose low molecular weight heparin, high dose low molecular weight heparin did not reduce symptomatic venous thromboembolism (0.57, 0.26 to 1.27) but increased major bleeding (1.87, 1.06 to 3.31); direct oral anticoagulants reduced symptomatic venous thromboembolism (0.53, 0.32 to 0.89) and did not increase major bleeding (1.23, 0.89 to 1.69). CONCLUSIONS Direct oral anticoagulants and low molecular weight heparin reduced venous thromboembolism compared with no active treatment but probably increased major bleeding to a similar extent. Direct oral anticoagulants probably prevent symptomatic venous thromboembolism to a greater extent than prophylactic low molecular weight heparin.Peer reviewe
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