Effect of dietary and synthetic chelating agents on the intestinal absorption of lead

The effect of a number of dietary and synthetic chelating agents on the intestinal absorption of lead has been examined using the everted sac preparation and the tracer isotope ²⁰³Pb. All the agents examined increased lead transport into the serosal compartment. An explanation of the way in which these agents modify the model to describe lead transport is proposed.     

放大镜让我看得更清楚——局部放大特效的制作

画面上，随着放大镜的运动，你可以看到图像的局部被放大——这种手法在表现形式较为夸张的Flash上经常被采用，其实在Premiere里我们也可以利用软件自身的合成功能做出这样的特效，它可以很好地突出画面上的某个细节，为我们的视频片段增加“此处无声胜有声”的指示效果。     

Multiplexed piezoelectric polymer tactile sensor

An electrically multiplexed robotic tactile sensor has been realized using a monolithic silicon-integrated circuit coupled to a piezoelectric polyvinylidene fluoride (PVDF) film. The integrated circuit incorporates 25 sensor electrodes arranged in a symmetrical 5 × 5 matrix. Each electrode occupies a 600 × 600 m?m square area, and they are separated from each other by 600 m?m. A 25-m?m thick PVDF film was experimentally determined to be compatible with the fabrication process, and also yielded very favorable tactile sensing performance characteristics. The response of the tactile sensor is essentially linear for loads spanning 0.8 to 60 g force (gmf). The response bandwidth is 33 Hz, the hysteresis level is very small, and crosstalk is not a significant problem. A novel precharge bias scheme has been implemented to stabilize the pre- and postload sensor response. A rudimentary tactile object image measurement process was evaluated to recognize the shapes of circular, rectangular, toroidal, and hexagonal loads.     

朦胧的魅力——擦图特效的制作

正所谓“千呼万唤始出来，尤抱琵琶半遮面”，再美的景象如果展现得过于直白也难免平淡。如果适当地半遮半掩，反而更容易引起大家的好奇心。其实，这个道理在视频的后期处理上也是通用，“花哨”的片头更容易吸引观者的眼球。本期我们就为大家介绍一种新的特效——擦图效果的制作。     

Circular arrays of radial and tangential dipoles for turnstile antennas

A method of obtaining a turnstile antenna from a circular array of radial or tangential dipoles is presented. Approximate current distributions, terminal admittances, and radiation fields are given for arrays of 3, 4, and 5 half-wavelength elements for various array diameters.     

Engineering a Novel Bivalent Oral Vaccine against Enteric Fever

Enteric fever is a major global healthcare issue caused largely by Salmonella enterica serovars Typhi and Paratyphi A. The objective of this study was to develop a novel, bivalent oral vaccine capable of protecting against both serovars. Our approach centred on genetically engineering the attenuated S. Typhi ZH9 strain, which has an excellent safety record in clinical trials, to introduce two S. Paratyphi A immunogenic elements: flagellin H:a and lipopolysaccharide (LPS) O:2. We first replaced the native S. Typhi fliC gene encoding flagellin with the highly homologous fliC gene from S. Paratyphi A using Xer-cise technology. Next, we replaced the S. Typhi rfbE gene encoding tyvelose epimerase with a spacer sequence to enable the sustained expression of O:2 LPS and prevent its conversion to O:9 through tyvelose epimerase activity. The resulting new strain, ZH9PA, incorporated these two genetic changes and exhibited comparable growth kinetics to the parental ZH9 strain. A formulation containing both ZH9 and ZH9PA strains together constitutes a new bivalent vaccine candidate that targets both S. Typhi and S. Paratyphi A antigens to address a major global healthcare gap for enteric fever prophylaxis. This vaccine is now being tested in a Phase I clinical trial ({"type":"clinical-trial","attrs":{"text":"NCT04349553","term_id":"NCT04349553"}}NCT04349553).     

ω‐Phthalimidoalkyl Aryl Ureas as Potent and Selective Inhibitors of Cholesterol Esterase

Cholesterol esterase (CEase), a serine hydrolase thought to be involved in atherogenesis and thus coronary heart disease, is considered as a target for inhibitor development. We investigated recombinant human and murine CEases with a new fluorometric assay in a structure–activity relationship study of a small library of ω‐phthalimidoalkyl aryl ureas. The urea motif with an attached 3,5‐bis(trifluoromethyl)phenyl group and the aromatic character of the ω‐phthalimide residue were most important for inhibitory activity. In addition, an alkyl chain composed of three or four methylene groups, connecting the urea and phthalimide moieties, was found to be an optimal spacer for inhibitors. The so‐optimized compounds 2 [1‐(3,5‐bis(trifluoromethyl)phenyl)‐3‐(3‐(1,3‐dioxoisoindolin‐2‐yl)propyl)urea] and 21 [1‐(3,5‐bis(trifluoromethyl)phenyl)‐3‐(4‐(1,3‐dioxoisoindolin‐2‐yl)butyl)urea] exhibited dissociation constants (K_i) of 1–19 μm on the two CEases and showed either a competitive ( 2 on the human enzyme and 21 on the murine enzyme) or a noncompetitive mode of inhibition. Two related serine hydrolases—monoacylglycerol lipase and fatty acid amide hydrolase—were inhibited by ω‐phthalimidoalkyl aryl ureas to a lesser extent.     

Age-Adjusted US Cancer Death Rate Predictions

The likelihood of developing cancer during one's lifetime is approximately one in two for men and one in three for women in the United States. Cancer is the second-leading cause of death and accounts for one in every four deaths. Evidence-based policy planning and decision making by cancer researchers and public health administrators are best accomplished with up-to-date age-adjusted site-specific cancer death rates. Because of the 3-year lag in reporting, forecasting methodology is employed here to estimate the current year rates based on complete observed death data up through three years prior to the current year. The authors expand the State Space Model (SSM) statistical methodology currently in use by the American Cancer Society (ACS) to predict age-adjusted cancer death rates for the current year. These predictions are compared with those from the previous Proc Forecast ACS method and results suggest the expanded SSM performs well.