A new impedance matching method for an ultra-wide band and dual circularly polarised feed

In traditional antenna design, metal components are not placed in the central part of the antenna as they change the characteristics of near field radiation. However, we show that placing a metal ring in the centre of the strip lines, which connect the ends of folded high-frequency dipoles, does not damage the performance of the feed. Instead it significantly improves the voltage standing wave ratio of the feed whilst other performance indicators are not compromised. Thus, our findings show an excellent way of improving the wide band feed. Based on this foundation, a new circularly polarised feed for operation between 0.4 to 2 GHz is introduced for the Chinese Spectral Radioheliograph in this paper. The issue of a feed impedance matching network is investigated. By optimising the impedance matching, the performance of the feed is enhanced with respect to the previous realisations of the Eleven feed. The simulation and experimental results show that the gain of the feed is about 10 dBi, and the VSWR is less than 2:1. In addition, the feed has a low axial ratio, fixed phase centre location, and constant beam width in the range of 0.4 to 2 GHz

Numerical Study of the Movement of Fine Particle in Sound Wave Field

AbstractInhalable particulate matter, especially PM2.5 is one of the main pollutants in China and it's harmful to both human health and atmosphere. Since the removal efficiency of traditional dust removal devices such as ESP for PM2.5 is very low, pretreatment becomes necessary before the dust gets into the dust remover. Acoustic agglomeration is one of the pretreatment technologies which uses sound wave with high intensity to make fine particles get agglomerate and grow up, and improves the efficiency of traditional dust removal devices for PM2.5. In sound wave field, fine particles are carried by the medium which in this paper is air, and vibrate with different amplitude because of different particle sizes, thus relative movement appears and then particles have more chances to collide and get agglomerate. In this paper, the movement of particles with different sizes in travelling wave sound field and standing wave sound field were calculated, including the velocity, displacement, amplitude and so on. The situation that Re<1 was considered and Viscous force in Stokes region was chose as the main forces here. Studying the movement of fine particle in sound field with different conditions has great meaning in learning the mechanisms of acoustic agglomeration

Deficiency of Mkrn2 causes abnormal spermiogenesis and spermiation, and impairs male fertility.

Although recent studies have shed insights on some of the potential causes of male infertility, new underlining molecular mechanisms still remain to be elucidated. Makorin-2 (Mkrn2) is an evolutionarily conserved gene whose biological functions are not fully known. We developed an Mrkn2 knockout mouse model to study the role of this gene, and found that deletion of Mkrn2 in mice led to male infertility. Mkrn2 knockout mice produced abnormal sperms characterized by low number, poor motility, and aberrant morphology. Disruption of Mkrn2 also caused failure of sperm release (spermiation failure) and misarrangement of ectoplasmic specialization (ES) in testes, thus impairing spermiogenesis and spermiation. To understand the molecular mechanism, we found that expression of Odf2, a vital protein in spermatogenesis, was significantly decreased. In addition, we found that expression levels of Odf2 were decreased in Mkrn2 knockout mice. We also found that MKRN2 was prominently expressed in the sperm of normal men, but was significantly reduced in infertile men. This result indicates that our finding is clinically relevant. The results of our study provided insights into a new mechanism of male infertility caused by the MKRN2 downregulation

Loss of <I>Nupr1</I> promotes engraftment by tuning the quiescence threshold of hematopoietic stem cells via regulation of the p53-checkpoint pathway

Hematopoietic stem cells (HSC) are dominantly quiescent under homeostasis, which is a key mechanism of maintaining the HSC pool for life-long hematopoiesis. Dormant HSC are poised to be immediately activated in certain conditions and can return to quiescence after homeostasis has been regained. At present, the molecular networks of regulating the threshold of HSC dormancy, if existing, remain largely unknown. Here, we show that deletion of Nupr1, a gene preferentially expressed in HSC, activated quiescent HSC under homeostasis, which conferred a competitive engraftment advantage for these HSC without compromising their stemness or multi-lineage differentiation capacity in serial transplantation settings. Following an expansion protocol, the Nupr1-/- HSC proliferated more robustly than their wild-type counterparts in vitro. Nupr1 inhibits the expression of p53 and rescue of this inhibition offsets the engraftment advantage. Our data reveal a new role for Nupr1 as a regulator of HSC quiescence, which provides insights for accelerating the engraftment efficacy of HSC transplantation by targeting the HSC quiescence-controlling network

Case Report: Potential Predictive Value of MMR/MSI Status and PD-1 Expression in Immunotherapy for Urothelial Carcinoma

Immune checkpoint inhibitors (ICIs) have shown encouraging outcomes against Lynch syndrome (LS)-associated colorectal cancer (CRC) and endometrial cancer with mismatch repair deficient/microsatellite instability–high (dMMR/MSI-H). However, there is as yet no clarity on the safety and efficacy of immunotherapy combined with chemotherapy in LS-associated urothelial carcinoma (UC). Here, we report a patient with recurrent and metastatic LS-associated UC who achieved sustained response to programmed death protein 1 (PD-1) inhibitor combined with chemotherapy over 31 months, during which the side effects of immunotherapy could be controlled and managed. Our findings indicate that the dMMR/MSI status and PD-1 expression in UC may have potential predictive value for the response to PD-1-targeted immunotherapy. Our case supports the inclusion of such combination and/or monotherapy for UC in clinical studies and using dMMR/MSI status and PD-1 expression as potential predictive biomarkers for assessment of the therapeutic response

Corrigendum: Case report: Potential predictive value of MMR/MSI status and PD-1 expression in immunotherapy for urothelial carcinoma

Immune checkpoint inhibitors (ICIs) have shown encouraging outcomes against Lynch syndrome (LS)-associated colorectal cancer (CRC) and endometrial cancer with mismatch repair deficient/microsatellite instability–high (dMMR/MSI-H). However, there is as yet no clarity on the safety and efficacy of immunotherapy combined with chemotherapy in LS-associated urothelial carcinoma (UC). Here, we report a patient with recurrent and metastatic LS-associated UC who achieved sustained response to programmed death protein 1 (PD-1) inhibitor combined with chemotherapy over 31 months, during which the side effects of immunotherapy could be controlled and managed. Our findings indicate that the dMMR/MSI status and PD-1 expression in UC may have potential predictive value for the response to PD-1-targeted immunotherapy. Our case supports the inclusion of such combination and/or monotherapy for UC in clinical studies and using dMMR/MSI status and PD-1 expression as potential predictive biomarkers for assessment of the therapeutic response