scholarly journals Rotational Dynamics of Optically Trapped Human Spermatozoa

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Elavarasan Subramani ◽  
Himanish Basu ◽  
Shyam Thangaraju ◽  
Sucheta Dandekar ◽  
Deepak Mathur ◽  
...  
Keyword(s):  
Near Infrared ◽  
Beat Frequency ◽  
Translational Motion ◽  
Rotational Dynamics ◽  
Sperm Cells ◽  
Integrated Optical ◽  
Fertility Potential ◽  
Live Sperm ◽  
Fertilization Capacity ◽  
Optically Trapped

Introduction. Optical trapping is a laser-based method for probing the physiological and mechanical properties of cells in a noninvasive manner. As sperm motility is an important criterion for assessing the male fertility potential, this technique is used to study sperm cell motility behavior and rotational dynamics.Methods and Patients. An integrated optical system with near-infrared laser beam has been used to analyze rotational dynamics of live sperm cells from oligozoospermic and asthenozoospermic cases and compared with controls.Results. The linear, translational motion of the sperm is converted into rotational motion on being optically trapped, without causing any adverse effect on spermatozoa. The rotational speed of sperm cells from infertile men is observed to be significantly less as compared to controls.Conclusions. Distinguishing normal and abnormal sperm cells on the basis of beat frequency above 5.6 Hz may be an important step in modern reproductive biology to sort and select good quality spermatozoa. The application of laser-assisted technique in biology has the potential to be a valuable tool for assessment of sperm fertilization capacity for improving assisted reproductive technology.

scholarly journals Integrated Optical Phased Arrays for Beam Forming and Steering

2021 ◽  
Vol 11 (9) ◽  
pp. 4017
Author(s):  
Yongjun Guo ◽  
Yuhao Guo ◽  
Chunshu Li ◽  
Hao Zhang ◽  
Xiaoyan Zhou ◽  
...  
Keyword(s):  
Near Infrared ◽  
Phased Arrays ◽  
Mechanical Stability ◽  
Building Blocks ◽  
High Yield ◽  
Beam Forming ◽  
Integrated Optical ◽  
Optical Phased Arrays ◽  
Infrared Spectral ◽  
Spectral Ranges

Integrated optical phased arrays can be used for beam shaping and steering with a small footprint, lightweight, high mechanical stability, low price, and high-yield, benefiting from the mature CMOS-compatible fabrication. This paper reviews the development of integrated optical phased arrays in recent years. The principles, building blocks, and configurations of integrated optical phased arrays for beam forming and steering are presented. Various material platforms can be used to build integrated optical phased arrays, e.g., silicon photonics platforms, III/V platforms, and III–V/silicon hybrid platforms. Integrated optical phased arrays can be implemented in the visible, near-infrared, and mid-infrared spectral ranges. The main performance parameters, such as field of view, beamwidth, sidelobe suppression, modulation speed, power consumption, scalability, and so on, are discussed in detail. Some of the typical applications of integrated optical phased arrays, such as free-space communication, light detection and ranging, imaging, and biological sensing, are shown, with future perspectives provided at the end.

scholarly journals Ultralong free-standing single crystal perovskite microwires with extremely low dark current

2021 ◽  
Author(s):  
Xiangshun Geng ◽  
Qi-Xin Feng ◽  
He Tian ◽  
Weijian Chen ◽  
Xiaoming Wen ◽  
...  
Keyword(s):  
Single Crystal ◽  
Dark Current ◽  
Near Infrared ◽  
Carrier Lifetime ◽  
Low Loss ◽  
Free Standing ◽  
Monoclinic Crystal ◽  
Monoclinic Crystal Structure ◽  
Integrated Optical ◽  
Integrated Optical Waveguide

Abstract Super long perovskite microwires (PMWs) are in a great demand in many fields such as low-loss microcables and integrated optical waveguide. Despite decades of research into PMWs, single crystal PMWs with several centimeters long have not been obtained. Here, ultralong (up to 7.6 centimeters) monoclinic crystal structure CH3NH3PbI3·DMF PMWs have been synthesized. The high-quality microwire exhibits long carrier lifetime of 1775.7 ns. The as-prepared free-standing PMWs can be integrated to any arbitrary substrate and 808 nm near-infrared photodetectors have been successfully demonstrated. The fabricated device shows a high light on/off ratio of 1.79×106 and an extremely low dark current of 2.5 fA at 1 V bias. This work provides a strategy for the solution growth of ultralong microwires.

scholarly journals Expression and function of ras proto-oncogene proteins in human sperm cells

1992 ◽  
Vol 102 (3) ◽  
pp. 487-494 ◽  
Author(s):  
R.K. Naz ◽  
K. Ahmad ◽  
P. Kaplan
Keyword(s):  
Sperm Cell ◽  
Acrosome Reaction ◽  
Cell Function ◽  
Beat Frequency ◽  
Human Sperm ◽  
Sperm Cells ◽  
Ras Protein ◽  
Head Displacement ◽  
Sperm Penetration ◽  
And Function

The presence and role of c-ras proteins were investigated in mature human sperm cells. The v-H-ras monoclonal antibody (mAb) against the c-ras protein, p21, reacted specifically with the acrosomal region of methanol-fixed as well as unfixed-live capacitated and non-capacitated human sperm cell in the indirect immunofluorescence technique. The v-H-ras mAb predominantly recognized c-ras protein of 21 kDa on the Western blot of lithium diiodosalicylate (LIS)-solubilized human sperm preparation. The incubation of sperm cells with v-H-ras mAb affected the sperm cell function in the human sperm penetration assay. The antibody significantly reduced the acrosome reaction and release of acrosin activity from the sperm cells. There was no effect of the mAb on percentage motility, although the mAb significantly affected various motility characteristics such as linearity, amplitude of lateral head displacement (ALH) and beat frequency, the motility parameters involved in the hyperactivation phenomenon of sperm cells leading to capacitation and acrosome reaction. These results suggest that the c-ras or c-ras-like proteins are present in mature sperm cell and may have a role in capacitation and/or acrosome reaction of human sperm cell.

scholarly journals Integrated Optic Sensing Spectrometer: Concept and Design

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1018 ◽  
Author(s):  
Gloria Micó ◽  
Bernardo Gargallo ◽  
Daniel Pastor ◽  
Pascual Muñoz
Keyword(s):  
Near Infrared ◽  
The Other ◽  
Spectrometric Analysis ◽  
Focal Points ◽  
Arrayed Waveguide Grating ◽  
Waveguide Grating ◽  
Integrated Optical ◽  
Infrared Wavelengths ◽  
Arrayed Waveguide

In this paper the concept and design of an integrated optical device featuring evanescent field sensing and spectrometric analysis is presented. The device, termed integrated optics sensing spectrometer (IOSS), consists of a modified arrayed waveguide grating (AWG) which arms are engineered into two sets having different focal points. Half of the arms are exposed to the outer media, while the other half are left isolated, thus the device can provide both sensing and reference spectra. Two reference designs are provided for the visible and near-infrared wavelengths, aimed at the determination of the concentration of known solutes through absorption spectroscopy.

scholarly journals Rotational dynamics of optically trapped nanofibers

2010 ◽  
Vol 18 (2) ◽  
pp. 822 ◽  
Author(s):  
Antonio Alvaro Ranha Neves ◽  
Andrea Camposeo ◽  
Stefano Pagliara ◽  
Rosalba Saija ◽  
Ferdinando Borghese ◽  
...  
Keyword(s):  
Rotational Dynamics ◽  
Optically Trapped
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