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A generic transmitter (TX) I/Q imbalance self-calibration method, which was designed based on a hybrid analog and digital structure, is proposed in this paper. The whole calibration scheme was implemented using low-complexity digital–analog circuits based on a zero-force feedback loop. In order to eliminate the negative effect of local oscillator (LO) harmonics on the calibration, we used a variable-delay line (VDL) in the analog domain instead of the digital phase compensator. The prototype chip was fabricated within a 0.2∼5.0 GHz direct-conversion transmitter in a 65 nm CMOS process, and measurements found an image rejection ratio (IRR) of 65 dBc. [ABSTRACT FROM AUTHOR]

Solar-induced chlorophyll fluorescence (SIF) can accurately reflect the photosynthetic capacity of vegetation and information on the physiological status of vegetation, which is of great research significance and application value. However, the low resolution of the solar-induced chlorophyll fluorescence product of the inverse performance makes it difficult to perform fine-scale studies. Therefore, concerning the above problem, this study proposes a random-forest-based downscaling method based on random forest. We used MODIS reflectance data to analyze GOME-2 SIF data at 0.5° resolution over the Chinese mainland in 2011 and created a monthly SIF product at 0.05° resolution for the Chinese mainland through downscaling. Then we performed a veracity check on the downscaled SIF data, analyzed factors (land cover type, climate zone type, and DEM) that could affect its accuracy, and explored the feasibility of using MODIS data in future GOME-2 SIF downscaling studies. The results show that the downscaled SIF is in remarkable agreement with the GOME-2 SIF, with an improved spatial resolution from 0.5° to 0.05°, and that the structural and physiological information of the SIF is well represented in the downscaled SIF, which is essential for assessing global photosynthesis. In addition, in the region with grassland land cover type, temperate grassland climate region, alpine vegetation climate region of Qinghai–Tibet Plateau, as well as the region with high altitude and complex terrain, the accuracy of using MODIS to downscale the GOME-2 SIF data is low. [ABSTRACT FROM AUTHOR]

Helicobacter pylori is a causative factor of various gastrointestinal tract diseases. As clinical antibiotic-based therapy for H. pylori infection might induce bacterial drug resistance, the in vivo eradication of H. pylori remains a huge challenge. In the present study, monoclonal antibody-conjugated liposomes loaded with indocyanine green (ICG) (Hp Ab-LiP-ICG) were successfully developed for targeted photoacoustic (PA) imaging-guided sonodynamic therapy (SDT) of H. pylori infection in vivo. Hp Ab-LiP-ICG showed high stability and favorable biocompatibility in acidic environment (pH 1.5) and was used for treating H. pylori- infected mice through oral administration. PA imaging showed that Hp Ab-LiP-ICG could precisely recognize and target H. pylori in the stomach. Following the targeting of Hp Ab-LiP-ICG to H. pylori , ICG was activated to generate singlet oxygen (1O 2) for eliminating H. pylori under ultrasound (US) irradiation. Pathological analysis revealed that the Hp Ab-LiP-ICG-mediated SDT eradicated H. pylori without unintended toxicity to normal tissues. In conclusion, the Hp Ab-LiP-ICG-mediated SDT might shed new light on treating H. pylori infection, indicating the clinical translational prospects of this therapy in near future. Traditional antibiotic-based therapy for Helicobacter pylori infections suffers from the risk of drug resistance. To meet this challenge, a monoclonal antibody-conjugated nanoliposome loaded with indocyanine green (ICG) (Hp Ab-LiP-ICG) was successfully developed, and efficient eradication of H. pylori was achieved in vivo by visual sonodynamic therapy (SDT). Hp Ab-LiP-ICG exhibited biocompatibility, targeting, and stability in the acidic microenvironment. Under ultrasound (US) irradiation in vitro , the Hp Ab-LiP-ICG nanoliposomes accumulated on the surface of H. pylori were activated to produce adequate singlet oxygen (1O 2) to eliminate H. pylori. Gastric mucous tissues infected with H. pylori recovered to the normal state after Hp Ab-LiP-ICG-mediated SDT without side effects, thus highlighting the clinical translational prospects of the prepared Hp Ab-LiP-ICG nanoliposome in near future. [Display omitted] [ABSTRACT FROM AUTHOR]

Effectively capturing and sensitively detecting cancer cells are critical to clinical diagnosis and cancer therapy. In this work, we prepared gold nanostar-decorated graphene oxide (GO-AuNSs) nanocomposites using a ultraviolet (UV)-induced strategy, and then modified them with a layer of bio-complex rBSA-FA (coupled reduced bovine serum albumin with folic acid) to generate GO-AuNSs@rBSA-FA nanocomposites. Herein, the application of GO and AuNSs not only strengthened the conductivity of the sensing platform but also guaranteed nanocomposites with biocompatible performance. Moreover, the adopted rBSA-FA layer could effectively enhance the stability and specificity towards gastric cancer cells (MGC-803). According to a systemic construction procedure, a novel electrochemical cytosensor based on GO-AuNSs@rBSA-FA was fabricated for MGC-803 cell detection. With the assistance of cyclic voltammetry (CV) and differential pulse voltammetry (DPV), the cytosensor reached a detection limit of 100 cell/mL in a wide linear range of 3 × 102~7 × 106 cell/mL towards MGC-803 cells. The good electrochemical characteristics for the cancer cell analysis indicate a promising prospect of this electrochemical cytosensor in clinical cancer diagnosis. [ABSTRACT FROM AUTHOR]

The photoelectrochemical biosensor based on double redox cycle amplification technology coupled with Tungsten diselenide and MXene-modified electrode was developed. Signal amplification technology is a commonly used method to improve the sensitivity. In this article, in the double redox cycle amplification method, p -aminophenol is used as the signal molecule, and squaric acid acts as a redox indicator. Tris(2-carboxyethyl) phosphine is an excellent reducing agent, which greatly improves the photoelectric response. Tungsten diselenide and MXene are used as photosensitive materials. In the presence of model target, respiratory syncytial virus RNA, the recombinase polymerase amplification process occurred because there is amplification template, so that the signal molecule p -aminophenol will be produced, leading to redox cycle was carried out, and the photocurrent signal is improved. In the absence of syncytial virus RNA, the photocurrent signal is low. The detection range of the biosensor is from 0.2 fM to 80 fM, and the detection limit reaches 30 aM for respiratory syncytial virus RNA. The method of introducing redox cycle amplification and Tungsten diselenide, MXene into photoelectrochemical biosensing provides a new idea for future biological analysis and has application potential. PEC assay using AuNPs/WSe 2 /Ti 3 C 2 as photoactive material with RPA for nucleic acid [Display omitted] • A novel material, Ti 3 C 2 @WSe 2 , was firstly synthesized. • A new double-redox cycling system, TCEP/SQA/4-AP, was discovered. • SQA, 4-AP cycling played a key role in enhancing PEC signals. • A PEC assay coupled with RPA for RSV detection with LOD 30 aM. [ABSTRACT FROM AUTHOR]