MIMO-Based Forward-Looking SAR Imaging Algorithm and Simulation

Multiple-input multiple-output (MIMO) radar imaging can provide higher resolution and better sensitivity and thus can be applied to targets detection, recognition, and tracking. Missile-borne forward-looking SAR (MFL-SAR) is a new and special MIMO radar mode. It has advantage of two-dimensional (2D) imaging capability in forward direction over monostatic missile-borne SAR and airborne SAR. However, it is difficult to obtain accurate 2D frequency spectrum of the target echo signal due to the high velocity and descending height of this platform, which brings a lot of obstacles to imaging algorithm design. Therefore, a new imaging algorithm for MFL-SAR configuration based on the method of series reversion is proposed in this paper. This imaging method can implement range compression, secondary range compression (SRC), and range cell migration correction (RCMC) effectively. Finally, some simulations of point targets and comparison results confirm the efficiency of our proposed algorithm

3-(4-Chloro­phen­yl)-2-(diisopropyl­amino)-1-benzofuro[3,2-d]pyrimidin-4(3H)-one

In the mol­ecule of the title compound, C22H22ClN3O2, the three fused rings of the benzofuro[3,2-d]pyrimidine system are almost coplanar. This ring system is oriented with respect to the substituted benzene ring at a dihedral angle of 79.05 (3)°. Intra­molecular C—H⋯N hydrogen bonding results in the formation of a six-membered ring. In the crystal structure, π–π stacking inter­actions involving the furan, pyrimidinone and benzene rings are present [centroid-to-centroid distances in the range 3.258 (1)–3.870 (1) Å]

Toxoplasma gondii infection in farmed wild boars (Sus scrofa) in three cities of northeast China

The apicomplexan protozoan parasite Toxoplasma gondii is a widely distributed etiological agent of foodborne illness. This parasite can cause production losses in livestock and serious disease in humans through consumption of contaminated meat. Pig meat is the most likely source of human infection, and wild boars may play a role in the transmission of T. gondii by serving as a reservoir host. This study aimed to investigate the seroprevalence of antibodies to T. gondii among farmed wild boars in China. In an 11-month survey, a total of 882 serum samples were obtained from farmed wild boars from three cities (Jilin City, Siping City, and Baishan City) in Jilin province, Northeast China and were tested for antibodies specific for T. gondii. Using modified agglutination test and a cutoff titer of 1:25, the prevalence of T. gondii infection in the examined samples was 10.0% (88 of 882). The highest seroprevalence was observed in animals from Jilin city (15.3%, 43/281) and followed by Siping (11.4%, 30/263) and Baishan (4.4%, 15/338). Logistic regression analysis revealed a significant correlation between the investigated geographic region and T. gondii infection. In addition, prevalence was higher in females compared to males, and the highest prevalence was detected in piglets. These findings indicate that farmed wild boars may become a source of foodborne toxoplasmosis, posing a food safety threat to the public health in the investigated areas. Implementation of effective measures to control T. gondii infection in farmed wild boars in China may be warranted

Successful thoracoscopic management of iatrogenic left subclavian arterial injury: a case report.

The subclavian artery at the thoracic outlet is in the deepest position of the thoracic cavity and is difficult to repair in this narrow space once injured, even if the surgery is converted to a thoracotomy. This article presents a successful left subclavian artery repair procedure at the thoracic outlet using a thoracoscopic approach, with a video demonstration, and describes its technical characteristics. The patient was planned for a left upper lobectomy through three-port thoracoscopic approach. Severe adhesions were found intraoperatively and an accidental left subclavian arterial injury occurred when dissecting the adhesions. We first clamped the proximal portion of the subclavian artery and then directly clamped the rupture site. Our first suture failed due to the limited suture angle and the mutual restriction between the needle holder and atraumatic vascular clamp. To freely control the needle holder, another assistant port was made in the seventh intercostal space (ICS). The arterial injury was finally successfully repaired using pledgetted suture. The operation time was 235 minutes and intraoperative blood loss was 800 mL. The pulsation of the left radial artery was normal postoperatively, and the patient was discharged on postoperative day 6. Appropriate strategies allow attempts to manage intraoperative hyperbaric arterial bleeding from the systemic circulation, such as bleeding caused by subclavian arterial injuries, by means of a thoracoscopic approach without conversion to thoracotomy

Influence of sources with a spectral peak in the detection of Cosmic Dawn and Epoch of Reionization

Foreground removal is one of the biggest challenges in the detection of the Cosmic Dawn (CD) and Epoch of Reionization (EoR). Various foreground subtraction techniques have been developed based on the spectral smoothness of foregrounds. However, the sources with a spectral peak (SP) at Megahertz may break down the spectral smoothness at low frequencies (< 1000 MHz). In this paper, we cross-match the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) extragalactic source catalogue with three other radio source catalogues, covering the frequency range from 72 MHz to 1.4 GHz, to search for sources with spectral turnover. 4,423 sources from the GLEAM catalogue are identified as SP sources, representing approximately 3.2 per cent of the GLEAM radio source population. We utilize the properties of SP source candidates obtained from real observations to establish simulations and test the impact of SP sources on the extraction of CD/EoR signals. We statistically compare the differences introduced by SP sources in the residuals after removing the foregrounds with three methods, which are polynomial fitting, Principal Component Analysis (PCA), and fast independent component analysis (FastICA). Our results indicate that the presence of SP sources in the foregrounds has a negligible influence on extracting the CD/EoR signal. After foreground subtraction, the contribution from SP sources to the total power in the two-dimensional (2D) power spectrum within the EoR window is approximately 3 to 4 orders of magnitude lower than the CD/EoR signal.Comment: 14 pages, 14 figure

6-Methyl-2-p-tolyl-4-[3-(trifluoro­meth­yl)phen­yl]pyridazin-3(2H)-one

In the title mol­ecule, C19H15F3N2O, the benzene rings of the tolyl and trifluoro­methyl­phenyl groups form dihedral angles of 64.1 (2) and 38.5 (2)°, respectively, with the pyridazine ring. The CF3 group is disordered over two orientations, with site-occupancy factors of ca 0.56 and 0.44

Genome Composition and Divergence of the Novel Coronavirus (2019-nCoV) Originating in China.

An in-depth annotation of the newly discovered coronavirus (2019-nCoV) genome has revealed differences between 2019-nCoV and severe acute respiratory syndrome (SARS) or SARS-like coronaviruses. A systematic comparison identified 380 amino acid substitutions between these coronaviruses, which may have caused functional and pathogenic divergence of 2019-nCoV