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Keratoconus is a progressive disease that seriously affects the eyesight of young people. Keratoconus often causes high myopia, irregular astigmatism, and some patients with advanced corneal scar, visual acuity significantly decreased. In the course of diagnosis and treatment of keratoconus, refractive reconstruction of keratoconus is the focus of clinical attention. After years of research and exploration, a variety of treatment methods in different stages of disease(non-progressive, progressive, advanced)for keratoconus patients refractive reconstruction, so that they can obtain good visual function. This paper mainly reviews the refractive reconstruction schemes of keratoconus in different periods, analyzes the advantages and disadvantages of various treatment schemes at home and abroad, and summarizes the characteristics of different treatment methods, with a view to providing theoretical reference and new treatment ideas for the diagnosis and treatment of keratoconus.

Gamma-aminobutyric acid (GABA) is a major inhibitory neurotransmitter that is present at a relatively low level throughout the normal adult human brain. Abnormal GABA levels are found in people with neurodegenerative disorders such as Parkinson’s disease, epilepsy, schizophrenia, depression, and others. Being able to measure the GABA concentration would be beneficial for patient groups with fluctuating GABA levels for better diagnosis and treatment. In this study, we explore the feasibility of using dielectric relaxation spectroscopy for the detection of GABA concentrations within a physiological range, with the perspective of miniaturization and use during implantation. Utilizing machine learning techniques, we were able to differentiate GABA concentrations down to 5 μm. This work investigates a novel use of dielectric relaxation spectroscopy, to assess if physiological GABA concentrations can be detected through permittivity measurements.

Plant growth regulators (PGRs) are defined as naturally occurring or artificially synthesized compounds. The functions of PGRs mainly include accelerating or delaying seed germination, breaking plant dormancy, stimulating or reducing bud elongation, inducing flowering and fruiting, and affecting the aging process. The application of PGRs has effectively promoted the growth of plants. However, the application concentration of PGRs is more than one millionth. The large amount of abuse and misuse of PGRs in the process of use not only reduces the yield of crops, but also exacerbates their residues in the environment, especially in agricultural products such as fruits and vegetables. So, they are detected in many environmental media like fruits, vegetables, and water. In addition, most PGRs are toxic, and some of them will undergo adsorption, desorption, hydrolysis, photolysis, microbial degradation, and other environmental behaviors after entering the soil. The decomposition products produced by this process are more toxic.In order to comprehensively understand the current status of PGRs pretreatment, analysis and test method, the common pretreatment methods of solid phase extraction and liquid-liquid extraction for typical PGRs in solid substrates such as fruits and vegetables, fertilizers and soil, and in liquid substrates such as water, edible oil and nutrient solution are summarized in this paper, as well as the analysis and testing techniques such as high-performance liquid chromatography (HPLC) and ultra-high performance liquid chromatography (UPLC). Moreover, to reduce the detection limit, high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) is also frequently used. At the same time, considering the strong natural attenuation ability of PGRs and the high toxicity of their intermediates, the advantages, disadvantages and applicability of different testing techniques are systematically summarized, taking into account the special structure and nature of PGRs, in order to fully understand the current status of pretreatment and analytical testing of PGRs and provide literature support for subsequent research on analytical testing, migration transformation, pollution evaluation and treatment of PGRs.Due to many impurities in the sample that can interfere with the detection, the appropriate pretreatment method can improve the accuracy of the test results. However, the sample pretreatment process accounts for more than 70% of the total analysis and test work, and about 50% of the error in the final test results comes from pretreatment. Therefore, establishing a fast, simple, and stable pretreatment method can effectively improve the efficiency and accuracy of analysis and detection. At present, the forms of environmental media detected for PGRs are mainly divided into two types: solid matrix samples (such as fruits, vegetables, fertilizers and soil, etc.) and liquid matrix samples (water, oil and nutrient solution, etc.). The related pretreatment methods are also mostly targeted at these two different forms of environmental media.Solid substrates involving PGRs mainly include fruits and vegetables, fertilizers and soil. Among them, fruits and vegetables are the most frequently detected solid substrates of PGRs, and some PGRs have also been detected in fertilizers, soil and other substrates. The pretreatment process of solid matrix samples can be divided into two parts: extraction and purification. Among them, solid phase extraction is the most commonly used extraction technology, and QuEChERS method is the most widely used purification method.Water, edible oil, and nutrient solution are the most frequently detected liquid substrates of PGRs. At present, liquid-liquid extraction is the most commonly used extraction method for liquid matrix. For the selection of extractants, the octanol-water partition coefficient of PGRs such as gibberellic acid and ethephon is less than 1, which is a strong polar compound and can be extracted by hydrophilic organic solvents such as methanol, ethanol and acetone; the polarity of most other PGRs such as forchlorfenuron and paclobutrazol is relatively weak, but it still belongs to the category of strong polarity compared with other kinds of compounds such as benzene and chloroethane (n-octanol-water partition coefficient>10). Therefore, the extractant can not only use methanol, but also use polar organic solvents such as ethyl acetate and chloroform that are insoluble in water. Although liquid-liquid extraction requires a lot of extractants, the high-water solubility of most PGRs makes them often directly detected by HPLC-MS/MS, which eliminates the complex pretreatment steps such as extraction and purification. In addition, because some PGRs have poor chromatographic characteristics or are not easily detected, the derivatization is also required to convert the components into derivatives suitable for analysis.Analytical and testing technologies mainly include gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS), HPLC/UPLC, HPLC-MS/MS, ion chromatography (IC), spectrophotometry (SP), capillary electrophoresis (CE), enzyme-linked immunosorbent assay (ELISA) and electrochemical sensor method.At present, the solubility of most PGRs in water (20℃) is 0.50-10g/L, and the octanol-water partition coefficient of most PGRs is 0-4, with strong hydrophilicity. Therefore, HPLC-MS/MS are applicable to the detection of almost all PGRs. However, HPLC-MS/MS are often used to detect the residues of PGRs in fruits and vegetables, followed by soil and fertilizer, while there are few related studies in natural water. This may be due to the rapid natural decay rate of PGRs in the natural environment, resulting in extremely small amounts of residues in natural water bodies such as surface water and groundwater that cannot be directly detected.GC has the advantages of low cost and easy maintenance, and GC-MS has become a conventional testing technology. However, GC-MS are greatly affected by sample matrix interference and require high pretreatment methods. In addition, due to the influence of the physical and chemical properties of different PGRs (such as abscisic acid and indole acetic acid with a boiling point over 400℃, or forchlorfenuron and cinnamic acid with hydroxyl and carboxyl groups), most PGRs have poor gas chromatographic characteristics and are not easily detected.The order of detection limits of PGRs is GC>HPLC>chromatography-mass spectrometry, and the lowest instrumental detection limit of chromatography-mass spectrometry is 10-5mg/kg. However, the higher solubility and the larger natural attenuation rate of most PGRs lead to the lower detection concentrations in complex environmental substrates such as soil and water, so there is still an urgent need to solve the problem of analytical testing of trace PGRs and its intermediates.In future, PGRs analysis and test method will focus on the analysis and detection of trace PGRs and their intermediates, as well as the development of new materials and technology-based methodologies.

Objective: To explore the perioperative nursing of a newborn with Beckwith-Wiedemann syndrome.

Due to the possibilities in miniaturization and wearability, photoplethysmography (PPG) has recently gained a large interest not only for heart rate measurement, but also for estimating heart rate variability, which is derived from ECG by convention. The agreement between PPG and ECG-based HRV has been assessed in several studies, but the feasibility of PPG-based HRV estimation is still largely unknown for many conditions. In this study, we assess the feasibility of HRV estimation based on finger PPG during rest, mild physical exercise and mild mental stress. In addition, we compare different variants of signal processing methods including selection of fiducial point and outlier correction. Based on five minutes synchronous recordings of PPG and ECG from 15 healthy participants during each of these three conditions, the PPG-based HRV estimation was assessed for the SDNN and RMSSD parameters, calculated based on two different fiducial points (foot point and maximum slope), with and without outlier correction. The results show that HRV estimation based on finger PPG is feasible during rest and mild mental stress, but can give large errors during mild physical exercise. A good estimation is very dependent on outlier correction and fiducial point selection, and SDNN seems to be a more robust parameter compared to RMSSD for PPG-based HRV estimation.

Electrical impedance spectroscopy is a well-established tool for monitoring changes in the electrical properties of tissue. Most tissue and organ types have been investigated in various studies. As for the small intestine, there are several published studies conducted on pig and rat models. This study investigates the changes in passive electrical properties of the complete wall of the human intestine non-invasively during ischemia. We aim to use the passive electrical properties to assess intestinal viability. The bioimpedance measurements were performed using a two-electrode set-up with a Solartron 1260 Impedance/gain-phase analyser. The small intestinal samples were resected from patients who underwent pancreaticoduodenectomy. Impedance measurements were conducted following resection by placing the electrodes on the surface of the intestine. A voltage was applied across the intestinal sample and the measured electrical impedance was obtained in the ZPlot software. Impedance data were further fitted into a Cole model to obtain the Cole parameters. The Py value was calculated from the extracted Cole parameters and used to assess the cell membrane integrity, thus evaluate the intestinal viability. Eight small intestinal segments from different patients were used in this study and impedance measurements were performed once an hour for a ten-hour period. One hour after resection, the impedance decreased, then increased the next two hours, before decreasing until the end of the experiment. For all the intestinal segments, the Py values first increased and reached a plateau which lasted for 1 - 2 hours, before it decreased irreversibly. The time interval where Py value reached the maximum is consistent with reported viable/non-viable limits from histological analysis.

To analyze mechanisms of action of glucocorticoid treatment for endoplasmic reticulum stress (ERS) in sensorineural hearing loss (SNHL), we aimed to evaluate the expression and activation status of the protein kinase RNA-like ER kinase (PERK)–C/EBP homologous protein (CHOP) pathway, which is the major pathway in the ERS.

BackgroundPostgraduates usually face more life challenges than undergraduate students, including social, emotional and financial issues, and the prevalence of mental health problems in postgraduates is higher than undergraduates. Therefore, the attention on postgraduates’ mental health status is needed.ObjectivesThe current study explored the relationship between postgraduates’ emotional intelligence and well-being by investigating the mediating effects of social support and psychological resilience and the relationship between them through the construction of a chain mediation model.Method1,228 postgraduates completed the Emotional Intelligence Scale, the Social Support Rate Scale, the Psychological Resilience Scale, and the Subject Well-being Scale.ResultsThere is a chain effect between postgraduates’ social support and psychological resilience mediated by their emotional intelligence and well-being, with a total effect value of 0.049.ConclusionEmotional intelligence has a predictive effect on postgraduates’ well-being. The mechanism of this effect includes the indirect effects of social support and psychological resilience. Study results revealed the relationship mechanism between emotional intelligence and postgraduates’ well-being, and provide reference for explorations of how to development postgraduates’ emotional intelligence and further improving their abilities to strengthen their emotional resilience.

A method for determination alanine, serine, glutamic acid, asparagine, theanine, glutamine in tea leaves by MSTFA derivatization has been established. And six amino acids were detected successfully. Isotope abundance of alanine, serine, glutamate, asparagine, theamine and glutamine are calculated accuracy, isotope abundance range from 10% to 98% (atom%). The relative standard deviations (RSD, n=3) were below 0.6%, and absolute deviation were below 0.6%. The method is quick, easy and accurate, which can meet the detection on isotope abundance of labeling amino acids in tea leaves. Besides, the method also can be applied to the determination of isotopic abundance of amino acids in other different crops, and provides technical support for the research of amino acids related transformation pathways and metabolic cycles in plants.

Electrical impedance spectroscopy (EIS) measurements on cells is a proven method to assess stem cell proliferation and differentiation. Cell regenerative medicine (CRM) is an emerging field where the need to develop and deploy stem cell assessment techniques is paramount as experimental treatments reach pre-clinical and clinical stages. However, EIS measurements on cells is a method requiring extensive post-processing and analysis. As a contribution to address this concern, we developed three machine learning models for three different stem cell lines able to classify the measured data as proliferation or differentiation laying the stone for future studies on using machine learning to profile EIS measurements on stem cells spectra.

In order to provide theoretical support for the use of unmanned equipment by the marine police force, this paper takes the current situation of the use of marine police drones in Asia-Pacific countries as the entry point, the type characteristics of marine police drones is introduced and the use of different materials for the typical task scenarios of the current marine police force drones, the needs of maritime police drones in different scenarios is analyzed and composed, and a variety of operational methods for the maritime use of drones by the marine police force are emphasized.

Background The operation control and safety protection functions of thorium molten salt reactor-solid fuel (TMSR-SF0) are independently implemented by the distributed control system based on experimental physics and industrial control system (EPICS) and a protection system based on field programmable gate array (FPGA). Since the protection system is set up to ensure the ultimate safety of the reactor, it is the most important part of the reactor control system for the safe operation of the reactor. Therefore, it is compulsory for integrating these two systems to meet the regulatory requirements of nuclear power human factors engineering. Purpose This study aims to realize the real-time communication between the protection system and control system for TMSR-SF0. Methods A distributed control system based on EPICS was designed and implemented to communicate with the protection system. The communication scheme between TMSR-SF0 control system and protection system was designed via the S7plc driver based on EPICS platform, and implemented by constructing the software input/output controller (IOC), configuring S7plc driver, designing IOC real-time database, developing the man-machine interface. Control system studio (CSS) was adopted to implement the display of communication scheme, and communication scheme was tested systematically by pre-set experiments. Results The test results show that the TMSR-SF0 control system can stably communicate with the serial device of the protection system for accurate data acquisition in real-time through this proposed communication scheme, satisfying all technical indexes and requirements of TMSR-SF0 control system. Conclusions The communication scheme of the S7plc driver based on the EPICS platform and the communication protocol defined by protection system can be used to implement scheme for communication between the TMSR-SF0 control system and the protection system, providing reference for similar communication design.

With the rapid development of modern science and technology, electrical automation becomes more and more important in the development of manufacturing industry. In the actual production activities, the application of artificial intelligent and virtual simulation technology in electrical engineering not only improves automation operation level, and reduces the cost and the error of manual operation, but also profits reasonable allocation for enterprise resources. In recent years, the demand for talents with new automation technology is increasing. Therefore, an innovative model of automation teaching reform based on information technology including artificial intelligent and virtual simulation technology is established to constitute an oriented training system from aspects of teaching and learning. Information technology plays an increasingly important role in the field of engineering training. The effective combination of electrical product, virtual simulation and intelligent technology can enhance the application value of teaching method and meet the practical needs of future engineering construction.

This paper is to present an important issue of fatigue failure in the design of multi-fasteners jointed structure. To avoid failure in the connection area, Sines criterion is utilized. Fatigue constraints are handled in the context of stress based topology optimization. To eliminate the high stresses caused by the finite element modeling, the control volume is defined to evaluate the stress states around the fasteners. The standard topology optimization is extended to minimize the structural compliance with fatigue failure constraints. To address singularity problems related to stress constraints, q-p relaxation is used. P-norm is used as the constraints aggregation scheme. Basing on the above, the design sensitivity of fatigue constraints is derived and calculated. The proposed method is verified by a numerical example of an assembled I-beam. The comparisons of the numerical results have shown the effect of the fatigue constraint.

For problem of single function of existing mine-used acquisition modules, the paper proposed a design scheme of mine-used multi-function acquisition module and introduced design methods of main hardware circuits and software programs of the module in details. The module uses PGA of ADC to achieve accessing function of multiple analog signals, adopts digital filter to realize multiple detections of frequency and digital signals, and realizes control function of CPU output. The application result showed that the module can acquire multiple signals of field sensors and run stably and reliably.