Mapper of the IGM Spin Temperature (MIST): Instrument Overview

The observation of the global 21 cm signal produced by neutral hydrogen gas in the intergalactic medium (IGM) during the Dark Ages, Cosmic Dawn, and Epoch of Reionization requires measurements with extremely well-calibrated wideband radiometers. We describe the design and characterization of the Mapper of the IGM Spin Temperature (MIST), which is a new ground-based, single-antenna, global 21 cm experiment. The design of MIST was guided by the objectives of avoiding systematics from an antenna ground plane and cables around the antenna, as well as maximizing the instrument's on-sky efficiency and portability for operations at remote sites. We have built two MIST instruments, which observe in the range 25-105 MHz. For the 21 cm signal, this frequency range approximately corresponds to redshifts 55.5 > z > 12.5, encompassing the Dark Ages and Cosmic Dawn. The MIST antenna is a horizontal blade dipole of 2.42 m in length, 60 cm in width, and 52 cm in height above the ground. This antenna operates without a metal ground plane. The instruments run on 12 V batteries and have a maximum power consumption of 17 W. The batteries and electronics are contained in a single receiver box located under the antenna. We present the characterization of the instruments using electromagnetic simulations and lab measurements. We also show sample sky measurements from recent observations at remote sites in California, Nevada, and the Canadian High Arctic. These measurements indicate that the instruments perform as expected. Detailed analyses of the sky measurements are left for future work.Comment: Comments welcom

Targeting the hypoxic fraction of tumours using hypoxia activated prodrugs

The presence of a microenvironment within most tumours containing regions of low oxygen tension or hypoxia has profound biological and therapeutic implications. Tumour hypoxia is known to promote the development of an aggressive phenotype, resistance to both chemotherapy and radiotherapy and is strongly associated with poor clinical outcome. Paradoxically, it is recognised as a high priority target and one therapeutic strategies designed to eradicate hypoxic cells in tumours are a group of compounds known collectively as hypoxia activated prodrugs (HAPs) or bioreductive drugs. These drugs are inactive prodrugs that require enzymatic activation (typically by 1 or 2 electron oxidoreductases) to generate cytotoxic species with selectivity for hypoxic cells being determined by (i) the ability of oxygen to either reverse or inhibit the activation process and (ii) the presence of elevated expression of oxidoreductases in tumours. The concepts underpinning HAP development were established over 40 years ago and have been refined over the years to produce a new generation of HAPs that are under preclinical and clinical development. The purpose of this article is to describe current progress in the development of HAPs focusing on the mechanisms of action, preclinical properties and clinical progress of leading examples

Sentinel Lymph Node Biopsy in Renal Tumors: Surgical Technique and Safety

Objective: To understand uncertainties and knowledge gaps regarding lymphatic drainage in renal tumours, we performed two prospective studies to demonstrate regional lymph node (LN) drainage with sentinel lymph node (SN) imaging and biopsy. Here, we report the technique and perioperative safety of retroperitoneal SN dissection with different surgical approaches. / Methods: 73 patients from the two trials were included in the analysis. Patients had cT1-2N0M0 renal tumours (</=10 cm) and underwent nephrectomy (46/63%) or partial nephrectomy (27/37%) with SN dissection after intraoperative detection with a γ-probe, and locoregional LND. Twenty-nine of 73 patients had open surgery, 27/73 laparoscopic and 17/73 robot-assisted laparoscopic (partial)nephrectomy. Surgery time, intraoperative adverse events (AE) according to CTCAE 5.0, and postoperative AE according to Clavien-Dindo (CD) were retrospectively assessed. / Results: There were no grade ≥3 intraoperative CTCAE 5.0 AEs. Postoperative AE rate was 16.4% of which 7 (9.6%) were CD grade 1-2 and 5 (6.8%) were 3a grade complications. There were no statistically significant differences between presence of AE, CD grade and surgical modality (p=0.27 and p=0.13, respectively). Blood loss was a median of 550 ml (IQR 200-900ml) and 225 (IQR 42-751ml) for partial nephrectomy (PN) and radical nephrectomy, respectively. Length of the procedure was 170 min (IQR 149-184min), 155 min (IQR 130-177min) 180 min (IQR 162-202min) in open, laparoscopic and robot-assisted procedures, respectively. / Conclusions: The addition of retroperitoneal SN dissection combined with locoregional LND during (partial)nephrectomy is surgically safe. Complication rate is low and does not differ between surgical approaches