Research progress of real-time sonoelastography to evaluate testicular spermatogenic function in non-obstructive azoospermia

Objective: The azoospermia is increasingly becoming prevalent year by year,which has been plaguing a great number of infertile couples. Testes biopsy is a gold index to evaluate the testicular spermatogenesis in patients with anspermia. However, it is more invasive and may not accurately reflect the whole spermatogenic function of the testes. In recent years, with the continuous development of ultrasound and assisted reproductive technology, real-time sonoelastography has been widely applied in the evaluation of spermatogenic function in patients with azoospermia. It is still at the initial stage, but shows good application prospects. In this paper, we will summarize and review the present status of male infertility and the clinical application and research progress of real-time sonoelastography in the evaluation of the testicular spermatogenic function of non-obstructive azoospermia patients.

Observation and simulation of wind waves near a typical reef lagoon in South China Sea

Due to the inference of the uneven shallow water seabed and the surrounding islands,the wind-generated waves around or in a reef lagoon are rather complicated,and critical to the safety of floating structures deployed near islands or inside a lagoon.This paper aims to find a feasible analysis tool for the wave simulations near islands and reefs.The proposed three methods of grid techniques of WAVEWATCH III(WW3)are assessed by using on-site measured data which was collected and accumulated for about 5 years since August 2014 by a wave observation system deployed inside and outside a reef lagoon in South China Sea.In the assessments,the wave statistics including the correlation coefficients,root mean square errors,and their variances are used to quantify the precisions of the simulation results of the significant wave heights,mean wave periods,and peak wave directions at two sites.Among the three methods,the Multi-scale Zone and Multi-scale grid Technique(MZMGT)established on unstructured triangular grids exhibits better results in terms of the accuracy and CPU cost.In addition,the bimodal feature of wave spectra was observed at both sites of the reef lagoon in different typhoon events.The wave characteristics inside the reef lagoon and open sea are also analyzed.

The characteristics of waves around an entrance of a lagoon in South China Sea

The characteristics of the waves around a lagoon entrance in South China Sea were observed during the past one and half years based on the wave measurements.The measured results show that the monsoon plays an important role.In summer,waves mostly come from the southeast,among which the wave components of non-dimensional periods larger than 0.2 are fetch-trapped waves.In winter the waves may be divided into two groups,the fetch-trapped waves and the waves from the open sea.The skewness of the directional distribution functions is within+8 around zero.The power relationship between the direction spread and kurtosis is also investigated.Besides,it is found that the waves with the significant wave heights greater than 1.5 m are caused by typhoons or cold air.The frequency components of wave energy driven by cold air appear in the high frequency range at first,and change to the lower frequency range afterwards.The waves driven by typhoon mostly come from the open sea.