Patterned Fabrication of Polyaniline Nanostructures for Ultrasensitive Biomolecule Detection

With more number of individuals becoming health conscious, the use of biosensors for medical diagnosis is rapidly growing. So far, many efforts have been made to meet this increasing demand. This work presents several routes to improve the biosensors performances and builds a sophisticated platform for sensing application. Single polypyrrole nanowire-based sensors were fabricated using a one-step electrochemical deposition method. A shadow mask was introduced to protect the biosensors from O2 plasma for the microfluidics integration. The results of nanowire resistance and fluorescence intensity indicated that the shadow mask played a key role in protecting the biosensor. The microfluidic aptasensors were consequently developed. The sensor demonstrated excellent specificity and sensitivity with faster response and rapid stabilization times. High yield polyaniline 1D nanowires and 2D nanobelts were fabricated by combining nanofabrication techniques and a chemical synthesis method. The PANI patterns possess good uniformity in morphology and electrical properties. The biosensors were found very sensitive to BNP targets, showing a response ~17% for 100 fg/mL BNP and a wide sensing range from 25 fg/mL to 5 pg/mL. Despite the reduced sensitivity compared to that in PBS, distinguishable changes in the FET sensors were observed over a range from 100 fg/mL to 5 pg/mL in serum. Significantly, the investigation about the Debye length opened an approach for further sensing performance improvement. Within the sub-threshold regime of the NWs, the sensor responses exhibited about 4 times greater than that in their linear region. Studies concentrated on the 2D PANI nanobelts revealed that they have similar rough surface and FET behavior to PANI-NWs. This suggested that the 2D PANI nanobelts would have comparable performances to 1D PANI-NWs as biosensors. A biosensor system based on the PNAI nanobelts was developed. The biosensors exhibited a good specificity and showed a linear range for BNP in buffer from 50 to 200 pg/mL. The demonstration of detecting BNP levels in human serum further confirmed that the sensor is capable of monitoring BNP in real samples. Those findings suggested that this biosensor system has a great potential for clinical use in future

Analysis of Annual Available Water Resources of a Representative Basin in Upper Loess Plateau

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Making Small Language Models Better Multi-task Learners with Mixture-of-Task-Adapters

Recently, Large Language Models (LLMs) have achieved amazing zero-shot learning performance over a variety of Natural Language Processing (NLP) tasks, especially for text generative tasks. Yet, the large size of LLMs often leads to the high computational cost of model training and online deployment. In our work, we present ALTER, a system that effectively builds the multi-tAsk Learners with mixTure-of-task-adaptERs upon small language models (with <1B parameters) to address multiple NLP tasks simultaneously, capturing the commonalities and differences between tasks, in order to support domain-specific applications. Specifically, in ALTER, we propose the Mixture-of-Task-Adapters (MTA) module as an extension to the transformer architecture for the underlying model to capture the intra-task and inter-task knowledge. A two-stage training method is further proposed to optimize the collaboration between adapters at a small computational cost. Experimental results over a mixture of NLP tasks show that our proposed MTA architecture and the two-stage training method achieve good performance. Based on ALTER, we have also produced MTA-equipped language models for various domains

Application status of cell models in clinical nutrition research

Traditional clinical nutrition research mostly stay at the stage of human and animal experiments. Cell model experiment has gradually become an important way in clinical nutrition research nowadays. Firstly, this review mainly summarizes the cells commonly used in nutrition research and gives a general introduction of diseases in clinical nutrition using cell models such as atherosclerotic cardio-cerebrovascular disease, sarcopenia, kidney diseases, tumor, gastrointestinal diseases, liver damage, allergic inflammation, burns and so on. Then it focuses mainly on the diseases which are the leading death causes of the Chinese residents, reviewing the use of cell models the advantages as well as their scientific significance and the development and application trend of cell model (3D cell, cytome, microfluidic, high throughput and high content). Finally, the limitations of cell model experiments in clinical nutrition are summarized, and new technologies used in cell model experiments of clinical nutrition are prospected

Detection of Cardiac Biomarkers Using Single Polyaniline Nanowire-Based Conductometric Biosensors

The detection of myoglobin (Myo), cardiac troponin I (cTnI), creatine kinase-MB (CK-MB), and b-type natriuretic peptide (BNP) plays a vital role in diagnosing cardiovascular diseases. Here we present single site-specific polyaniline (PANI) nanowire biosensors that can detect cardiac biomarkers such as Myo, cTnI, CK-MB, and BNP with ultra-high sensitivity and good specificity. Using single PANI nanowire-based biosensors integrated with microfluidic channels, very low concentrations of Myo (100 pg/mL), cTnI (250 fg/mL), CK-MB (150 fg/mL), and BNP (50 fg/mL) were detected. The single PANI nanowire-based biosensors displayed linear sensing profiles for concentrations ranging from hundreds (fg/mL) to tens (ng/mL). In addition, devices showed a fast (few minutes) response satisfying respective reference conditions for Myo, cTnI, CK-MB, and BNP diagnosis of heart failure and for determining the stage of the disease. This single PANI nanowire-based biosensor demonstrated superior biosensing reliability with the feasibility of label free detection and improved processing cost efficiency due to good biocompatibility of PANI to monoclonal antibodies (mAbs). Therefore, this development of single PANI nanowire-based biosensors can be applied to other biosensors for cancer or other diseases

An integrated sensor platform for food reassurance

Given the increasing pressures on the global food system to produce more from the planet’s diminishing resources, the need to produce food that is safe to consume and reflects the information declared on pack is becoming ever more difficult to achieve as shown by the recent ‘horsemeat’ scandal. The salutary lesson that emerged from this latest food scandal was the vulnerability of the highly complex food supply networks that we rely on. For example, the wafers in the popular KitKat are ‘glued’ together with plaster-of-Paris which is sourced from India. These convoluted food networks increase the potential for product contamination through either physical, chemical or microbial means, with potentially life threatening consequences. Recent issues include the 2005 Sudan Red dye scandal, in which food products were contaminated with the potentially carcinogenic dye, and the 2013 worldwide recall of dairy products manufactured by Fonterra, because whey products suspected of being contaminated with botulism-causing bacteria were found during safety tests. It is important to remain vigilant in identifying and solving emerging challenges in global food networks to ensure a high level of consumer trust in the supply chain and food sold for consumption

Polysaccharide Extracted from Laminaria japonica

This study aimed to determine the effect of topically applied Laminaria polysaccharide (LP) on skin aging. We applied ointment containing LP (10, 25, and 50 μg/g) or vitamin E (10 μg/g) to the dorsal skin of aging mice for 12 months and young control mice for 4 weeks. Electron microscopy analysis of skin samples revealed that LP increased dermal thickness and skin collagen content. Tissue inhibitor of metalloprotease- (TIMP-) 1 expression was upregulated while that of matrix metalloproteinase- (MMP-) 1 was downregulated in skin tissue of LP-treated as compared to untreated aging mice. Additionally, phosphorylation of c-Jun N-terminal kinase (JNK) and p38 was higher in aging skin than in young skin, while LP treatment suppressed phospho-JNK expression. LP application also enhanced the expression of antioxidative enzymes in skin tissue, causing a decrease in malondialdehyde levels and increases in superoxide dismutase, catalase, and glutathione peroxidase levels relative to those in untreated aging mice. These results indicate that LP inhibits MMP-1 expression by preventing oxidative stress and JNK phosphorylation, thereby delaying skin collagen breakdown during aging

A rapid and nondestructive method to determine the distribution map of protein, carbohydrate and sialic acid on Edible bird’s nest by hyper-spectral imaging and chemometrics

Edible bird’s nest (EBN) is a precious functional food in Southeast Asia. A rapid and nondestructive method for determining the distribution map of protein content (PC), carbohydrate content (CC) and sialic acid content (SAC) on EBN sample was proposed. Firstly, 60 EBNs were used for hyperspectral image acquisition, and components content (PC, CC and SAC) were determined by chemical analytical methods. Secondly, the spectral signals of EBN hyperspectral image and EBN components content were used to build calibration models. Thirdly, spectra of each pixel in EBN hyperspectral image were extracted, and these spectra were substituted in the calibration models to predict the PC, CC and SAC of each pixel in the EBN image, so the visual distribution maps of PC, CC and SAC on the whole EBN were obtained. It is the first time to show the distribution tendency of PC, CC and SAC on the whole EBN sample

Amine-responsive bilayer films with improved illumination stability and electrochemical writing property for visual monitoring of meat spoilage

Amine-responsive bilayer films were developed by using agar (AG), anthocyanins (AN), gellan gum (GG) and TiO2 nanoparticles for visual monitoring of meat spoilage. The AG-AN layer worked as the sensing layer to volatile amines, while GG-TiO2 layer served as the light barrier layer and simultaneously the conducting layer to improve the illumination stability and electrochemical writing ability of the AG-AN layer, respectively. The Scanning electron microscopy (SEM) images and X-ray diffraction (XRD) spectra indicated the successful fabrication of bilayer films. Illumination experiments showed that the incorporation of TiO2 in the GG-TiO2 layer significantly improved the illumination stability of AN in the AG-AN layer. Meanwhile, electrochemical writing process could be easily conducted on the AG-AN layer in the presence of GG-TiO2 layer, indicating the feasibility of ink-free printing on bilayer biopolymer films. The AG-AN/GG-2%TiO2 film presented a limit of detection of 0.018 mM to trimethylamine (TMA), a typical basic gas generated during meat spoilage. Based on its good illumination stability and sensing ability to basic gases, the AG-AN/GG-2%TiO2 film exhibited rose red-to-green color changes along with the spoilage of pork and silver carp, indicating its great potential for monitoring meat spoilage in intelligent food packaging