Flux-induced isometry gauging in heterotic strings

We study the effect of flux-induced isometry gauging of the scalar manifold in N=2 heterotic string compactification with gauge fluxes. We show that a vanishing theorem by Witten provides the protection mechanism. The other ungauged isometries in hyper moduli space could also be protected, depending on the gauge bundle structure. We also discuss the related issue in IIB settin

Experimental realization of a highly structured search algorithm

The highly structured search algorithm proposed by Hogg[Phys.Rev.Lett. 80,2473(1998)] is implemented experimentally for the 1-SAT problem in a single search step by using nuclear magnetic resonance technique with two-qubit sample. It is the first demonstration of the Hogg's algorithm, and can be readily extended to solving 1-SAT problem for more qubits in one step if the appropriate samples possessing more qubits are experimentally feasible.Comment: RevTex, 11 pages + 3 pages of figure

Therapeutic Effect of Targeting Branched-Chain Amino Acid Catabolic Flux in Pressure-Overload Induced Heart Failure.

Background Branched-chain amino acid (BCAA) catabolic defect is an emerging metabolic hallmark in failing hearts in human and animal models. The therapeutic impact of targeting BCAA catabolic flux under pathological conditions remains understudied. Methods and Results BT2 (3,6-dichlorobenzo[b]thiophene-2-carboxylic acid), a small-molecule inhibitor of branched-chain ketoacid dehydrogenase kinase, was used to enhance BCAA catabolism. After 2 weeks of transaortic constriction, mice with significant cardiac dysfunctions were treated with vehicle or BT2. Serial echocardiograms showed continuing pathological deterioration in left ventricle of the vehicle-treated mice, whereas the BT2-treated mice showed significantly preserved cardiac function and structure. Moreover, BT2 treatment improved systolic contractility and diastolic mechanics. These therapeutic benefits appeared to be independent of impacts on left ventricle hypertrophy but associated with increased gene expression involved in fatty acid utilization. The BT2 administration showed no signs of apparent toxicity. Conclusions Our data provide the first proof-of-concept evidence for the therapeutic efficacy of restoring BCAA catabolic flux in hearts with preexisting dysfunctions. The BCAA catabolic pathway represents a novel and potentially efficacious target for treatment of heart failure

Analysis of plastic recycling and breast cancer prognosis using vibrational spectroscopy

This thesis is split into three parts. Part I: An Automatic Self-optimising Continuous-flow Reactor for Electrosynthesis Assembly-line and/or continuous, steady-state strategies are widely spreading in the manufacturing industry. Electrosynthesis in an automatic continuous flow manner is drawing more and more attention to both pharmaceutical industry and research. This part describes the develop and use of an automated self-optimising continuous-flow electrochemistry reactor system. The main focus of this work is to develop an bi-language (MATLAB and LabVIEW), server-client structure automation software framework to conduct automation, control and monitoring of flow electrochemistry processes, which enables quick system setup, reconfiguration and high flexibility. Stable noisy optimisation by branch and fit (SNOBFIT) and simplex algorithm (modified simplex and super-modified simplex method) were developed and tested on simulators, which were then applied to the synthesis action of methoxylation of N-formylpyrrolidine and electro-oxidation of 3-bromobenzyl alcohol. Searching of the optimum operation condition of a reaction in an automatic manner is a major step forward to establish convenient and straightforward use of organic electrosynthesis in routine laboratory synthesis or industrial applications. Part II: Applying FTIR Imaging to Address Challenges in Plastic Recycling Plastic pollution is ubiquitous throughout the earth, and reusing/recycling of plastic has the potential to reduce the global abundance and weight of waste plastics. The main focus of this work is investigating plastic sample using Fourier transform infrared spectroscopy (FTIR), single point and imaging, for recycling purpose. An quantitative calibration of talcum concentration in talcum reinforced virgin polypropylene sample with IR peak ratio/integration was conducted, and the application of the result to analyse the talcum disperse in polypropylene matrix was reported. Micron scale FTIR imaging was conducted on the film sample. Pseudo-colour image visualising the distribution of talcum in the polypropylene matrix indicated a highly uneven distribution, a result of the reprocessing method. FTIR imaging was applied to investigate the composite structures of 'real-world' composites sample for recycled industry plastics, including: virgin polypropylene with short milled recycled carbon fibre, virgin polypropylene, maleic anhydride grafted polypropylene with carbon fibre, acrylonitrile butadiene styrene with calcium carbonate and virgin polypropylene with poly(ethylene terephthalate) on the micron scale. Imaging technique in FTIR spectroscopy not only provide micron level spatial information of the composition but also direct solution of improving the inter-facial interactions between compositions, thus improving the physical/chemical performance of the plastic products. Those pilot studies provide insights into applying FTIR imaging for plastic sample analysis. Part III: FTIR spectroscopy for Breast Cancer Prognosis Breast cancer is a major cause of deaths for females worldwide. Cancer prognosis provides a patient's likely outcome based on their current standing, which can help to decide the treatment for the patient. The current golden standard prognosis index, Nottingham Prognosis Index, is a time-consuming, un-objective process to which limited confidence can be assigned because of inherent operator variability. Applying Fourier transform infrared spectroscopy (FTIR) imaging to breast cancer tissue offers a non-destructive, label free tool for cellular and extracellular breast cancer tissue studying. In this work, we evaluate the prognostic ability of FTIR spectroscopy for identifying different grades of breast cancer. Different combinations of data pre-processing, feature extraction and unsupervised learning methodologies are explored. Spectrum quality control methods are applied to correct or minimise spectral problems, including high noise level, baseline offset and outlier. A multi-stage data analysis algorithm developed can provide statistical control over the breast cancer classification process and produce a precise cancer prognosis

A Task Allocation Algorithm with Weighted Average Velocity Based on Online Active Period

In some complex scientific calculation, the resources of the calculation are very large. To a certain extent, the improvement of the computer level has met the needs of many computing, but a lot of more complex calculation cannot still be effectively resolved. Volunteer computing is a computational method that divides the complexity of computing tasks into simple subtasks, and collects the results of volunteer computing resources to solve the subtasks. In this calculation process, the task assignment module is an extremely important part of the whole computing platform. Many of the existing task allocation algorithms (TAA) are used to group by the similar conditions of the volunteer computer. TAA used in this work grouped by the computers with similar online active period, and the computation efficiency is improved by using the weighted average velocity as a parameter. The experimental results showed that TAA with the weighted average velocity based on online active period can effectively improve the performance of the volunteer computing platform. Keywords: Volunteer computing; Task allocation algorithm; Weighted average velocity; Online active perio

Preparation of pseudo-pure states by line-selective pulses in Nuclear Magnetic Resonance

A new method of preparing the pseudo-pure state of a spin system for quantum computation in liquid nuclear magnetic resonance (NMR) was put forward and demonstrated experimentally. Applying appropriately connected line-selective pulses simultaneously and a field gradient pulse techniques we acquired straightforwardly all pseudo-pure states for two qubits in a single experiment much efficiently. The signal intensity with the pseudo-pure state prepared in this way is the same as that of temporal averaging. Our method is suitable for the system with arbitrary numbers of qubits. As an example of application, a highly structured search algorithm----Hogg's algorithm was also performed on the pseudo-pure state $\mid 00>$ prepared by our method.Comment: RevTEX,10 pages,5 PS figure

Infrared Solution‐Processed Quantum Dot Solar Cells Reaching External Quantum Efficiency of 80% at 1.35 µm and Jsc in Excess of 34 mA cm−2

Developing low‐cost photovoltaic absorbers that can harvest the short‐wave infrared (SWIR) part of the solar spectrum, which remains unharnessed by current Si‐based and perovskite photovoltaic technologies, is a prerequisite for making high‐efficiency, low‐cost tandem solar cells. Here, infrared PbS colloidal quantum dot (CQD) solar cells employing a hybrid inorganic–organic ligand exchange process that results in an external quantum efficiency of 80% at 1.35 µm are reported, leading to a short‐circuit current density of 34 mA cm−2 and a power conversion efficiency (PCE) up to 7.9%, which is a current record for SWIR CQD solar cells. When this cell is placed at the back of an MAPbI3 perovskite film, it delivers an extra 3.3% PCE by harnessing light beyond 750 nm.Peer ReviewedPostprint (author's final draft

The relationship between health belief and sleep quality of Chinese college students: The mediating role of physical activity and moderating effect of mobile phone addiction

BackgroundPoor sleep quality has become a common health problem encountered by college students.MethodsHealth belief scale (HBS), physical activity rating scale (PARS-3), mobile phone addiction tendency scale (MPATS) and Pittsburgh sleep quality index (PSQI) were adopted to analyze the data collected from survey questionnaires, which were filled out by 1,019 college students (including 429 males and 590 females) from five comprehensive colleges and universities from March 2022 to April 2022. The data collected from survey questionnaires were analyzed using SPSS and its macro-program PROCESS.Results(1) Health belief, physical activity, mobile phone addiction and sleep quality are significantly associated with each other (P < 0.01); (2) physical activity plays a mediating role between health belief and sleep quality, and the mediating effects account for 14.77%; (3) mobile phone addiction can significantly moderate the effect size of health belief (β = 0.062, p < 0.05) and physical activity (β = 0.073, P < 0.05) on sleep quality, and significantly moderate the effect size of health belief on physical activity (β = −0.112, p < 0.001).ConclusionThe health belief of college students can significantly improve their sleep quality; college students’ health belief can not only improve their sleep quality directly, but also improve their sleep quality through physical activity; mobile phone addiction can significantly moderate the effect size of health belief on sleep quality, the effect size of health belief on physical activity, and the effect size of physical activity on sleep quality