73 research outputs found
Simplicial quantum dynamics
Present-day quantum field theory can be regularized by a decomposition into
quantum simplices. This replaces the infinite-dimensional Hilbert space by a
high-dimensional spinor space and singular canonical Lie groups by regular spin
groups. It radically changes the uncertainty principle for small distances.
Gaugeons, including the gravitational, are represented as bound fermion-pairs,
and space-time curvature as a singular organized limit of quantum
non-commutativity.
Keywords: Quantum logic, quantum set theory, quantum gravity, quantum
topology, simplicial quantization.Comment: 25 pages. 1 table. Conference of the International Association for
Relativistic Dynamics, Taiwan, 201
Bridged Carbon Fabric Membrane with Boosted Performance in AC Line Filtering Capacitors
High frequency responsive capacitors with lightweight, flexibility, and miniaturization are among the most vital circuit components because they can be readily incorporated into various portable devices to smooth out the ripples for circuits. Electrode materials no doubt are at the heart of such devices. Despite tremendous efforts and recent advances, the development of flexible and scalable high frequency responsive capacitor electrodes with superior performance remains a great challenge. Herein, a straightforward and technologically relevant method is reported to manufacture a carbon fabric membrane glued by nitrogen doped nanoporous carbons produced through a polyelectrolyte complexation induced phase separation strategy. The as obtained flexible carbon fabric bearing a unique hierarchical porous structure, and high conductivity as well as robust mechanical properties, serves as the free standing electrode materials of electrochemical capacitors. It delivers an ultrahigh specific areal capacitance of 2632 F cm amp; 8722;2 at 120 Hz with an excellent alternating current line filtering performance, fairly higher than the state of the art commercial ones. Together, this system offers the potential electrode material to be scaled up for AC line filtering capacitors at industrial level
Rheological Characteristics of Municipal Thickened Excess Activated Sludge (TEAS): Impacts of pH, Temperature, Solid Concentration and Polymer Dose
Rheological characterization of sludge is known to be an essential tool to optimize flow, mixing and other process parameters in wastewater treatment plants. This study deals with the characterization of thickened excess activated sludge in comparison to raw primary sludge and excess activated sludge. The effects of key parameters (total solid concentration, temperature, and pH) on the rheology and flow behavior of thickened excess activated sludge were studied. The rheological investigations were carried out for total solid concentration range of 0.9–3.7 %w/w, temperature range of 23–55 °C, and pH range of 3.6–10.0. Different rheological model equations were fitted to the experimental data. The model equations with better fitting were used to calculate the yield stress, apparent, zero-rate, infinite-rate viscosities, flow consistency index, and flow index. The decrease in concentration from 3.7 to 3.1 %w/w resulted in a drastic reduction of yield stress from 27.6 to 11.0 Pa, while a further reduction of yield stress to 1.3 Pa was observed as solid concentration was reduced to 1.3 %w/w. The viscosity at higher shear rate (>600 s−1) decreased from 0.05 Pa·s down to 0.008 Pa·s when the total solid concentration was reduced from 3.7 to 0.9 %. Yield stress decreased from 20.1 Pa down to 8.3 Pa for the Bingham plastic model when the temperature was raised from 25 to 55 °C. Activation energy and viscosity also showed decreasing trends with increasing temperature. Yield stress of thickened excess activated sludge increased from a value of 6.0 Pa to 8.3 Pa when the pH was increased from 3.6 to 10.0. The effect of polymer dose on the rheological behavior of the thickening of excess activated sludge was also investigated, and the optimum polymer dosage for enhanced thickener performance was determined to be 1.3 kg/ton DS
Abnormality in glutamine-glutamate cycle in the cerebrospinal fluid of cognitively intact elderly individuals with major depressive disorder: a 3-year follow-up study
Major depressive disorder (MDD), common in the elderly, is a risk factor for dementia. Abnormalities in glutamatergic neurotransmission via the N-methyl-D-aspartate receptor (NMDA-R) have a key role in the pathophysiology of depression. This study examined whether depression was associated with cerebrospinal fluid (CSF) levels of NMDA-R neurotransmission-associated amino acids in cognitively intact elderly individuals with MDD and age- and gender-matched healthy controls. CSF was obtained from 47 volunteers (MDD group, N = 28; age- and gender-matched comparison group, N = 19) at baseline and 3-year follow-up (MDD group, N = 19; comparison group, N = 17). CSF levels of glutamine, glutamate, glycine, L-serine and D-serine were measured by highperformance liquid chromatography. CSF levels of amino acids did not differ across MDD and comparison groups. However, the ratio of glutamine to glutamate was significantly higher at baseline in subjects with MDD than in controls. The ratio decreased in individuals with MDD over the 3-year follow-up, and this decrease correlated with a decrease in the severity of depression. No correlations between absolute amino-acid levels and clinical variables were observed, nor were correlations between amino acids and other biomarkers (for example, amyloid-β42, amyloid-β40, and total and phosphorylated tau protein) detected. These results suggest that abnormalities in the glutamine–glutamate cycle in the communication between glia and neurons may have a role in the pathophysiology of depression in the elderly. Furthermore, the glutamine/glutamate ratio in CSF may be a state biomarker for depression
Optimization of critical slip surface in unsaturated slopes subjected to rain infiltration by CBO algorithm
Slope stability analysis is one of the most important issues in the safe design of infrastructures. This is mainly due to the historical hazards arising from instability of soil mass, leading to serious consequences including both fatality and financial loss. According to the field observations, rainfall is one of the most important factors stimulating the instability of unsaturated slopes. Nonetheless, most classical solution methods ignore the unsaturated conditions by simply assuming the soil conditions to be dry or completely saturated. In order to cope with this limitation, commercial software has been improved for simulation of two-phase flow under unsaturated conditions such as the GeoStudio software package. However, the scientific challenge as one of the limitations of commercial software is the optimization of critical slip surface under transient precipitation. Therefore, the main objective of this research is to develop a homemade computer code in MATLAB based on the Colliding Bodies Optimization (CBO) algorithm so that it can be used for studying complex two-phase flow problems more efficiently in terms of time. The code can effectively calculate and optimize the factor of safety against stability considering the effects of precipitation applied to the slope boundaries by employing Richards’ equation. Calculations of factor of safety are performed by assuming the circular wedge geometry and Bishop's method. According to the algorithm, the centroid of the wedge of slip circles in space is randomly guided and as a result, the coordinates of the circle collision points are obtained within the slope. If the consistency conditions are satisfied, the wedge is divided into parts and the factor of safety is calculated by finite difference method. This process will continue until the optimal factor of safety is obtained. Finally, the results of the code are validated against the output of GeoStudio 2018. The results confirm that the new method is robust in predicting the critical conditions much more rapidly than the software. Although changes in the factor of safety are minor for the simple validation example, the most important feature of the new code is that it reduces the CPU occupancy by 71% on average, independent of the type of CPU
Opinions Regarding Benzodiazepine Teaching and Prescribing Among Trainees in Psychiatry
© 2017, Academic Psychiatry. Objectives: Benzodiazepines are widely prescribed for a variety of symptoms and illnesses. There has been limited investigation on the training psychiatry residents receive regarding benzodiazepine prescribing. This study surveyed US psychiatric trainees about their didactic and clinical experience with benzodiazepines, investigating how experience with benzodiazepines may shape trainees’ opinions and likelihood to prescribe. Methods: The 14-question online survey was distributed to residents and fellows at US training programs through an invitation from their training directors. Results: Of 466 programs contacted, with an estimated 1345 trainees, a total of 97 programs (20.8%) and 424 trainees (31.5%) responded. The analyses focused only on the 342 general psychiatry trainees who responded. Most trainees reported having formal didactics on benzodiazepines, and earlier training was correlated with higher trainee quality of instruction assessments (p \u3c 0.01). Most trainees rated their instructors as Above or Well Above Average. Trainees cited the observation and opinion of supervisors as the two most important factors affecting likelihood of future benzodiazepine prescribing. Trainees commonly reported pressure from patients to prescribe benzodiazepines but were split on perceived pressure from supervisors about prescribing and whether a bias exists against prescribing at their program or in general. Conclusion: The survey indicated that psychiatry trainees generally feel adequately trained through didactic and clinical experience with benzodiazepines. Trainees perceived pressure by patients to prescribe benzodiazepines, but generally felt comfortable in managing benzodiazepine usage. Psychiatry attendings’ opinions on benzodiazepines most impacted trainees. Influences on trainees’ prescribing patterns are important variables that can impact future benzodiazepine prescribing
A novel 3D in vitro tissue model for bone-metastasized breast cancer: A preclinical tool in drug discovery and testing
A 3D, Compartmental Tumor-Stromal Microenvironment Model of Patient-Derived Bone Metastasis
Bone is a frequent site of tumor metastasis. The bone–tumor microenvironment is heterogeneous and complex in nature. Such complexity is compounded by relations between metastatic and bone cells influencing their sensitivity/resistance to chemotherapeutics. Standard chemotherapeutics may not show efficacy for every patient, and new therapeutics are slow to emerge, owing to the limitations of existing 2D/3D models. We previously developed a 3D interface model for personalized therapeutic screening, consisting of an electrospun poly lactic acid mesh activated with plasma species and seeded with stromal cells. Tumor cells embedded in an alginate-gelatin hydrogel are overlaid to create a physiologic 3D interface. Here, we applied our 3D model as a migration assay tool to verify the migratory behavior of different patient-derived bone metastasized cells. We assessed the impact of two different chemotherapeutics, Doxorubicin and Cisplatin, on migration of patient cells and their immortalized cell line counterparts. We observed different migratory behaviors and cellular metabolic activities blocked with both Doxorubicin and Cisplatin treatment; however, higher efficiency or lower IC50 was observed with Doxorubicin. Gene expression analysis of MDA-MB231 that migrated through our 3D hybrid model verified epithelial–mesenchymal transition through increased expression of mesenchymal markers involved in the metastasis process. Our findings indicate that we can model tumor migration in vivo, in line with different cell characteristics and it may be a suitable drug screening tool for personalized medicine approaches in metastatic cancer treatment
A 3D, Compartmental Tumor-Stromal Microenvironment Model of Patient-Derived Bone Metastasis
Bone is a frequent site of tumor metastasis. The bone–tumor microenvironment is heterogeneous and complex in nature. Such complexity is compounded by relations between metastatic and bone cells influencing their sensitivity/resistance to chemotherapeutics. Standard chemotherapeutics may not show efficacy for every patient, and new therapeutics are slow to emerge, owing to the limitations of existing 2D/3D models. We previously developed a 3D interface model for personalized therapeutic screening, consisting of an electrospun poly lactic acid mesh activated with plasma species and seeded with stromal cells. Tumor cells embedded in an alginate-gelatin hydrogel are overlaid to create a physiologic 3D interface. Here, we applied our 3D model as a migration assay tool to verify the migratory behavior of different patient-derived bone metastasized cells. We assessed the impact of two different chemotherapeutics, Doxorubicin and Cisplatin, on migration of patient cells and their immortalized cell line counterparts. We observed different migratory behaviors and cellular metabolic activities blocked with both Doxorubicin and Cisplatin treatment; however, higher efficiency or lower IC50 was observed with Doxorubicin. Gene expression analysis of MDA-MB231 that migrated through our 3D hybrid model verified epithelial–mesenchymal transition through increased expression of mesenchymal markers involved in the metastasis process. Our findings indicate that we can model tumor migration in vivo, in line with different cell characteristics and it may be a suitable drug screening tool for personalized medicine approaches in metastatic cancer treatment
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