25 research outputs found
Environmental chemicals impact dog semen quality in vitro and may be associated with a temporal decline in sperm motility and increased cryptorchidism
Adverse temporal trends in human semen quality and cryptorchidism in infants have been associated with exposure to environmental chemicals (ECs) during development. Here we report that a population of breeding dogs exhibit a 26 year (1988–2014) decline in sperm quality and a concurrent increased incidence of cryptorchidism in male offspring (1995–2014). A decline in the number of males born relative to the number of females was also observed. ECs, including diethylhexyl phthalate (DEHP) and polychlorinated biphenyl 153 (PCB153), were detected in adult dog testes and commercial dog foods at concentrations reported to perturb reproductive function in other species. Testicular concentrations of DEHP and PCB153 perturbed sperm viability, motility and DNA integrity in vitro but did not affect LH stimulated testosterone secretion from adult testis explants. The direct effects of chemicals on sperm may therefore contribute to the decline in canine semen quality that parallels that reported in the human
Performance improvement of plasmonic-based thin film assisted MSM-PDs
Das, NK ORCiD: 0000-0002-3396-4194This paper presents numerical study on a novel type of plasmonic-based metalsemiconductor-metal photodetector (MSM-PD) for extraordinary light absorption, which can drastically modify transmission spectra when a thin film is designed inside the central subwavelength slit. This strategy assists to recover non-propagating evanescent waves at nano-scale. Furthermore, by focusing on metallic nanostructures and surface plasmon polaritons (SPPs), and their contribution to the confinement of light in subwavelength scale, we introduce the concept of plasmonic lens that significantly reduces metal induced energy losses. The proposed novel photodetector with a thin film on the central slit assists the
device to absorb ∼280-times more light than the bare slit plasmonic-based MSM-PDs
Performance improvement of plasmonic-based thin film assisted MSM-PDs
This paper presents numerical study on a novel type of plasmonic-based metalsemiconductor-metal photodetector (MSM-PD) for extraordinary light absorption, which can drastically modify transmission spectra when a thin film is designed inside the central subwavelength slit. This strategy assists to recover non-propagating evanescent waves at nano-scale. Furthermore, by focusing on metallic nanostructures and surface plasmon polaritons (SPPs), and their contribution to the confinement of light in subwavelength scale, we introduce the concept of plasmonic lens that significantly reduces metal induced energy losses. The proposed novel photodetector with a thin film on the central slit assists the
device to absorb ∼280-times more light than the bare slit plasmonic-based MSM-PDs
Nano-structured metal-semiconductor-metal photodetector for sensor network systems
The advanced and smart ways to produce complex nano-structures have incorporated new capabilities in various aspects of science and technology where structures on nano-meter scales are desirable including high-speed communication and sensor networks, and future biomedical sensors and detectors. In recent years, there has been a growing interest towards the miniaturization of optical and electrical components with faster and more efficient performance. The development of nano-materials and nano-structures design provides great opportunity for building multifunctional sensing elements which are smaller and more efficiently incorporated. Furthermore they have other useful characteristics like reduced production cost and minimized power consumption. Wireless sensor network systems have been identified as one of the most important technologies for the 21st century (Chong et. al., 2003). It can be deduced from its name that sensor network systems are composed of several sensor nodes, where each component is responsible for a function in the whole system, where it can consist of different kinds of sensors such as, thermal, visual, biomedical, infrared, acoustics, etc. Recent wireless communication system development requires a concurrent speedy advancement of sensors characteristics as well as the system performance. Therefore, it is very important to make the progress in sensors design with tiny dimensions, suitable for communication over a sensor network system with specified purposes such as, monitoring different parameters, namely humidity, temperature, light in household, cities, and different environments (Ian-Akyildiz et al., 2002). The main focus of this review is to design and model an optimized plasmonics-based metal-semiconductor-metal photodetectors (MSM-PDs) with sub-wavelength architectures that is useful for high-speed optical communication systems and sensor network systems. Nano-structures designed on top of the electrodes trigger surface plasmon polaritons (SPPs) excitation and enable routing and manipulation of the light to be eventually trapped into the device active region
Nano-structured gratings for improved light absorption efficiency in solar cells
Due to the rising power demand and substantial interest in acquiring green energy from sunlight, there has been rapid development in the science and technology of photovoltaics (PV) in the last few decades. Furthermore, the synergy of the fields of metrology and fabrication has paved the way to acquire improved light collecting ability for solar cells. Based on recent studies, the performance of solar cell can improve due to the application of subwavelength nano-structures which results in smaller reflection losses and better light manipulation and/or trapping at subwavelength scale. In this paper, we propose a numerical optimization technique to analyze the reflection losses on an optimized GaAs-based solar cell which is covered with nano-structured features from the same material. Using the finite difference time domain (FDTD) method, we have designed, modelled, and analyzed the performance of three different arrangements of periodic nano-structures with different pitches and heights. The simulated results confirmed that different geometries of nano-structures behave uniquely towards the impinging light
Novel therapies for cutaneous T-cell lymphoma: what does the future hold?
Introduction: Cutaneous T-cell lymphomas (CTCLs) represent a group of extranodal non-Hodgkin lymphomas, of which mycosis fungoides (MF) is the most frequent. Standard therapeutic approaches are well established and often achieve stable disease. However, cure for MF is rare and thus novel therapies are needed. Areas covered: This review provides a discussion of the most promising new therapeutic approaches in the management of MF and other rare CTCLs. It includes targeted therapies with antibodies against surface molecules on malignant T cells (e.g., brentuximab), novel chemotherapeutic agents (e.g., pralatrexate), small-molecule compounds (e.g., panobinostat) and evidence of emerging targets in CTCLs (e.g., anti-IL-31). It also provides discussion of immune checkpoint inhibitors such as anti-PD1 that are worth considering in the treatment of leukaemic CTCL variants. Finally, it gives a brief overview of the possible use of stem-cell transplantation. Expert opinion: There is no doubt that progress has been made in the treatment of CTCLs with new, innovative and promising therapies approaching. However, there is still an urgent need to identify and test additional targets in well-designed clinical trials