We reported on GaN microcavity (MC) lasers combined with one rigid TiO high-contrast grating (HCG) structure as the output mirror. The HCG structure was directly fabricated on the GaN structure without an airgap. The entire MC structure comprised a bottom dielectric distributed Bragg reflector; a GaN cavity; and a top HCG reflector, which was designed to yield high reflectance for transverse magnetic (TM)- or transverse electric (TE)-polarized light. The MC device revealed an operation threshold of approximately 0.79 MW/cm when pulsed optical pumping was conducted using the HCG structure at room temperature. The laser emission was TM polarized with a degree of polarization of 99.2% and had a small divergence angle of 14° (full width at half maximum). This laser operation demonstration for the GaN-based MC structure employing an HCG exhibited the advantages of HCGs in semiconductor lasers at wavelengths from green to ultraviolet.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6736857 | PMC |
http://dx.doi.org/10.1038/s41598-019-49604-0 | DOI Listing |
Andrology
January 2025
Department of Digestion, Metabolism and Reproduction, Institute of Reproductive and Developmental Biology, Hammersmith Campus, Imperial College London, London, UK.
Luteinizing hormone (LH), along with its agonist choriongonadotropin (hCG) in humans, is the key hormone responsible for the tropic regulation of the gonadal function. LH and hCG act through their cognate receptor, the luteinizing hormone/choriongonadotropin receptor (LHCGR; more appropriately LHR in rodents lacking CG), located in the testis in Leydig cells and in the ovary in theca, luteal, and luteinizing granulosa cells. Low levels in LHCGR are also expressed in numerous extragonadal sites.
View Article and Find Full Text PDFAsian J Androl
January 2025
Global Andrology Forum, 130 West Juniper Lane, Moreland Hills, OH 44022, USA.
Azoospermia, defined as the absence of sperm in the ejaculate, is a well-documented consequence of exogenous testosterone (ET) and anabolic-androgenic steroid (AAS) use. These agents suppress the hypothalamic-pituitary-gonadal (HPG) axis, leading to reduced intratesticular testosterone levels and impaired spermatogenesis. This review examines the pathophysiological mechanisms underlying azoospermia and outlines therapeutic strategies for recovery.
View Article and Find Full Text PDFCell Commun Signal
January 2025
Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
Background: Cryptorchidism is the absence of one or both testicles in the scrotum at birth, being a risk factor for testis cancer and infertility. The most effective method to treat cryptorchidism is orchiopexy, followed by human chorionic gonadotropin (hCG) therapy; however, a portion of treated patients do not show a significant improvement in testis volume and vascularization after adjuvant therapy.
Methods: In this study, we generated an in vitro model to predict the patient response to hCG by cultivating and treating primary cells derived from five cryptorchid patients' biopsies of gubernaculum testis, the ligament that connects the testicle to the scrotum.
In Brief: Formation and function of the corpus luteum strongly rely on active angiogenesis. This study demonstrates the role of the hypoxia-inducible factor (HIF) in luteinization with no effect on fertility.
Abstract: HIFs are transcription factors responsible for sensing low oxygen levels and, in response, inducing the transcription of numerous genes.
J Coll Physicians Surg Pak
December 2024
Reproductive Medicine Centre, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, China.
Objective: To determine the clinical and embryo laboratory factors that affect the clinical pregnancy rate of infertile patients with endometriosis (EMs), and establish a model for predicting clinical pregnancy.
Study Design: An observational study. Place and Duration of the Study: Reproductive Medicine Centre, Jiangxi Provincial Maternal and Child Health Hospital, China, from January 2016 to December 2023.
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