There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

基礎講座 電気泳動(Electrophoresis)

Microfluidic paper-based analytical devices (μPADs) are a new class of point-of-care diagnostic devices that are inexpensive, easy to use, and designed specifically for use in developing countries. (To listen to a podcast about this feature, please go to the Analytical Chemistry multimedia page at pubs.acs.org/page/ancham/audio/index.html.)

http://pubs.acs.org/doi/pdf/10.1021/ac9013989

Diagnostics for the Developing World: Microfluidic Paper-Based Analytical Devices

This communication describes the first paper-based microfluidic device that is capable of generating its own power when a sample is added to the device. The microfluidic device contains galvanic cells (that we term “fluidic batteries”) integrated directly into the microfluidic channels, which provides a direct link between a power source and an analytical function within the device. This capability is demonstrated using an example device that simultaneously powers a surface-mount UV LED and conducts an on-chip fluorescence assay.

/pdf/fluidic-batteries-as-low-cost-sources-of-power-in-paper-bb88fjtiy9.pdf

“Fluidic batteries” as low-cost sources of power in paper-based microfluidic devices

Point-of-care (POC) and point-of-use assays are critical for identifying and measuring the quantity of analytes in a variety of environments that lack access to laboratory infrastructure. In quantitative versions of these assays, both the duration of the assay and the output signal must be measured. Measurements of time most often are performed using a timer that is external to the platform of the assay. Such measurements are relatively simple and inexpensive, and in some cases, can be integrated into the device itself. In contrast, measurements of signal typically are accomplished using hand-held electrochemical, absorbance, reflectance, transmittance, or fluorescence readers, and as such, these measurements can be complicated, time-consuming, and expensive, particularly in the context of extremely resource-limited environments such as remote villages in the developing world. The World Health Organization has identified the use of external readers as a challenge that must be overcome when creating ideal POC diagnostic assays for use in the developing world. In fact, they have listed “equipment-free” as one of seven necessary attributes for diagnostic tests in these regions. Herein, we describe two complimentary assay strategies that address this issue. By using paper-based microfluidic devices, we show that the level of an analyte can be quantified by simply measuring time: no external electronic reader is required for the quantitative measurement (Figure 1). The methods involve either 1) tracking the time required for a sample to react with and ultimately pass through a hydrophobic detection reagent in a single conduit within a threedimensional (3D) paper-based microfluidic device (Figure 1a) (we call this a digital assay), or 2) counting the number of bars that become colored after a fixed assay period in a related paper-based microfluidic device (Figure 1b; we refer to this as an analog assay). The methods described herein require only a timer, the ability to see color, and/or the

Quantifying Analytes in Paper‐Based Microfluidic Devices Without Using External Electronic Readers

We have previously identified an allele of the human SP-A2 gene that occurs with greater frequency in an RDS population [12]. Because of the importance of SP-A in normal lung function and its newly emerging role in innate host defense and regu-lation of inflammatory processes, we wish to better characterize genotypes of both SP-A1 and SP-A2 genes. It has been determined that SP-D shares similar roles in immune response. Therefore, in this report we 1) describe a novel, non radioactive PCR based-cRFLP method for genotyping both SP-A and SP-D; 2) describe two previously unpublished biallelic polymorphisms within the SP-D gene; 3) present the partial sequence of one new SP-A1 allele (6A14) and describe other new SP-A1 and SP-A2 alleles; and 4) describe additional methodologies for SP-A genotype assessment. The ability to more accurately and efficiently genotype samples from individuals with various pulmonary diseases will facilitate population and family based association studies. Genetic poly-morphisms may be identified that partially explain individual disease susceptibility and/or treatment effectiveness.

/pdf/novel-non-radioactive-simple-and-multiplex-pcr-crflp-methods-5gloxzr1dd.pdf

Novel, Non-Radioactive, Simple and Multiplex PCR-cRFLP Methods for Genotyping Human SP-A and SP-D Marker Alleles

This Communication describes a strategy for designing stimuli-responsive plastics that are capable of responding to chemical signals in the environment by changing shape. The plastics consist of patterned mixtures of poly(phthalaldehyde) polymers in which each polymer contains a different end-capping group, or "trigger". Each polymer within the plastic is capable of responding to a different signal and depolymerizing once the signal reacts with the trigger. This process of depolymerization enables the plastic to alter its physical features quickly and with a magnitude that depends on the length of the responsive polymer.

Patterned plastics that change physical structure in response to applied chemical signals.

This paper describes an efficient and high throughput method for fabricating three-dimensional (3D) paper-based microfluidic devices. The method avoids tedious alignment and assembly steps and eliminates a major bottleneck that has hindered the development of these types of devices. A single researcher now can prepare hundreds of devices within 1 h.

Scott T. Phillips

Papers

“Fluidic batteries” as low-cost sources of power in paper-based microfluidic devices

Quantifying Analytes in Paper‐Based Microfluidic Devices Without Using External Electronic Readers

Novel, Non-Radioactive, Simple and Multiplex PCR-cRFLP Methods for Genotyping Human SP-A and SP-D Marker Alleles

Patterned plastics that change physical structure in response to applied chemical signals.

High throughput method for prototyping three-dimensional, paper-based microfluidic devices.