中医药优势日渐凸现

中国传统医学,在五千年的历史的长河中不断的前进和发展,历经大浪淘沙和坎坷走到今日,日渐受到世界医学的广泛关注。随着现代科学技术的进步,中医药如何顺应时代的发展,在继承的基础上发展中医药,创新中医药。如何继承,如何创新无疑成为困扰中医药发展的关键性问题……

用发展的眼光看待中医药

中国传统医学,在五千年的历史的长河中不断的前进和发展,历经大浪淘沙和坎坷走到今日,日渐受到世界医学的广泛关注。随着现代科学技术的进步,中医药如何顺应时代的发展,在继承的基础上发展中医药,创新中医药。如何继承,如何创新无疑成为困扰中医药发展的关键性问题……

Mechanical response of bridge piles in high-steep slopes and sensitivity study

The bridge piles located in high-steep slopes not only endure the loads from superstructure, but also the residual sliding force as well as the resistance from the slope. By introducing the Winkler foundation theory, the mechanical model of piles-soils-slopes system was established, and the equilibrium differential equations of pile were derived. Moreover, an analytic solution for identifying the model parameters was provided by means of power series method. A project with field measurement was compared with the proposed method. It is indicated that the lateral loads have great influences on the pile, the steep slope effect is indispensable, and reasonable diameter of the pile could enhance the bending ability. The internal force and displacements of pile are largely based upon the horizontal loads applied on pile, especially in upper part.

Nerve growth factor and diarrhea-predominant irritable bowel syndrome(IBS-D):a potential therapeutic target?

Irritable bowel syndrome （IBS） is a common functional gastrointestinal disorder characterized by recurrent abdominal pain or discomfort associated with abnormal bowel habits. Diarrhea-predominant IBS （IBS-D） is a major subtype of IBS, the predominant manifestations of which are abdominal pain and diarrhea. The pathogenesis of IBS-D remained unknown until recently. The effects of psychosocial stress, central hypervigilance, neuroendocrine abnor- mality, disturbed gastrointestinal motility, mucosal immune activation, intestinal barrier dysfunction, visceral hyper- sensitivity （VH）, altered gut flora, and genetic susceptibility may be involved in its development. Recently, increased attention has been placed on the neural-immune-endocrine network mechanism in IBS-D, especially the role of var- ious neuroendocrine mediators. As a member of the neurotrophin family, nerve growth factor （NGF） has diverse bio- logical effects, and participates in the pathogenesis of many diseases. Basic studies have demonstrated that NGF is associated with inflammatory- and stress-related VH, as well as stress-related intestinal barrier dysfunction. The aim of this study is to summarize recent literature and discuss the role of NGF in the pathophysiology of IBS-D, especially in VH and intestinal barrier dysfunction, as well as its potential as a therapeutic target in IBS-D.

Application of machine learning to the identification of quick and highly sensitive clays from cone penetration tests

Geotechnical classification is vital for site characterization and geotechnical design.Field tests such as the cone penetration test with pore water pressure measurement(CPTu)are widespread because they represent a faster and cheaper alternative for sample recovery and testing.However,classification schemes based on CPTu measurements are fairly generic because they represent a wide variety of soil conditions and,occasionally,they may fail when used in special soil types like sensitive or quick clays.Quick and highly sensitive clay soils in Norway have unique conditions that make them difficult to be identified through general classification charts.Therefore,new approaches to address this task are required.The following study applies machine learning methods such as logistic regression,Naive Bayes,and hidden Markov models to classify quick and highly sensitive clays at two sites in Norway based on normalized CPTu measurements.Results showed a considerable increase in the classification accuracy despite limited training sets.

First-principles calculations of elasticity of minerals at high temperature and pressure

The elasticity of minerals at high temperature and pressure （PT） is critical for constraining the composition and temperature of the Earth＇s interior and understand better the deep water cycle and the dynamic Earth. First-principles calcula- tions without introducing any adjustable parameters, whose results can be comparable to experimental data, play a more and more important role in investigating the elasticity of minerals at high PT mainly because of （1） the quick increasing of computational powers and （2） advances in method. For example, the new method reduces the computation loads to one-tenth of the traditional method with the comparable precise as the traditional method. This is extraordinarily helpful because first-principles calculations of the elasticity of minerals at high PT are extremely time-consuming. So far the elasticity of most of lower mantle minerals has been investigated in detail. We have good idea on the effect of temperature, pressure, and iron concentration on elasticity of main minerals of the lower mantle and the unusual softening in bulk modulus by the spin crosso- ver of iron in ferropericlase. With these elastic data the lower mantle has been constrained to have 10-15 wt% ferropericlase, which is sufficient to generate some visible effects of spin crossover in seismic tomography. For example, the spin crossover causes that the temperature sensitivity of P wave at the depth of -1700 km is only a fraction of that at the depth of -2300 kin. The disruptions of global P wave structure and of P wave image below hotspots such as Hawaii and Iceland at similar depth are in consistence with the spin crossover effect of iron in ferropericlase. The spin crossover, which causes anomalous ther- modynamic properties of ferropericlase, has also been found to play a control role for the two features of the large low shear velocity provinces （LLSVPs）： the sharp edge and high elevation up to 1000 km above core-mantle boundary. All these results clearly suggest the spin crossover of iron in the lower mantle. The theoretical investigations for the elasticity of minerals at the upper mantle and water effect on elasticity of minerals at the mantle transition zone and subducting slab have also been con- ducted extensively. These researches are critical for understanding better the composition of the upper mantle and water dis- tribution and transport in the Earth＇s mantle. Most of these were static calculations, which did not include the vibrational （temperature） effect on elasticity, although temperature effect on elasticity is basic because of high temperature at the Earth＇s interior and huge temperature difference between the ambient mantle and the subducting slab. Including temperature effect on elasticity of minerals should be important future work. New method developed is helpful for these directions. The elasticity of iron and iron-alloy with various light elements has also been calculated extensively. However, more work is necessary in order to meet the demand for constraining the types and amount of light elements at the Earth＇s core. Keywords Mantle temperature, Mantle composition, Composition of Earth＇s core, Ab initio method

A hybrid magnetometer towards femtotesla sensitivity under ambient conditions

Detecting magnetic field is of great importance for many applications,such as magnetoencephalography and underground prospecting.There have been many magnetometers being widely used since the age of Hall magnetometer.One of the magnetometers,the superconducting quantum interference device,is capable of measuring femtotesla magnetic fields at cryogenic temperature.However,a solid-state magnetometer with femtotesla sensitivity under ambient conditions remains elusive.Here we present a hybrid magnetometer based on the ensemble nitrogen-vacancy centers in diamond with the sensitivity of(195±60)fT/Hz^(1/2)under ambient conditions,which can be further advanced to 11 fT/Hz^(1/2)at 100 Hz with cutting-edge fabrication technologies.Our method will find potential applications in biomagnetism and geomagnetism.

Study of a novel pressure sensor based on optical microring resonator

We propose a novel pressure sensor based on the combination of the ring resonator with two straight waveguides and a two-end fixed beam.The principle of this device is acquiring the system static pressure by monitoring the changes in the transmission wavelength shift of the ring resonator with double waveguides.The numerical results show that the sensitivity of the system is up to 49.3 pm/kPa while the pressure range is 0—300 kPa.The thickness of the fixed beam is an important factor which impacts the sensitivity of the system.This device can provide support for fabricating high sensitivity and low cost micro pressure sensors.