Simple Screening Method Research Articles

Comparative analysis of SARC-F-EBM, Ishii test, and six other screening tools for sarcopenia in Chinese community-dwelling older adults: a cross-sectional diagnostic study

To assess the relative performance of simple screening methods for sarcopenia in Chinese community-dwelling older adults. Data of older adults aged ≥ 60 were collected through a cross-sectional investigation. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019 criteria. The accuracy of screening methods was evaluated using sensitivity, specificity, receiver operating characteristic (ROC) curves and area under the ROC curves (AUC). The AUC value greater than 0.8 represented the good screening ability. A total of 918 older adults (44.3% men, mean age 70.4 ± 6.5 years) were included in this study. The overall prevalence rates of possible sarcopenia, confirmed sarcopenia, and severe sarcopenia were 59.5%, 12.8%, and 5.9%, respectively. In men, the SARC-F-EBM and Ishii tests indicated good screening capabilities for confirmed sarcopenia, with an AUC of 0.81 (95% CI: 0.77–0.85) and 0.80 (95% CI: 0.76–0.84), respectively. In women, the highest AUC was also achieved using the SARC-F-EBM at 0.79 (95% CI: 0.75–0.82), followed by the Ishii test at 0.77 (95% CI: 0.74–0.81), showing the moderate efficacy. A ranking diagram showed that SARC-F-EBM was most likely to be considered the best method for diagnosing sarcopenia in terms of AUC and sensitivity, regardless of sex. We recommend the SARC-F-EBM for sarcopenia screening in community-dwelling Chinese older adults when respondents are able to answer the questionnaire accurately; otherwise, the Ishii test consisting entirely of objective measures could be used.

A New Validated Method for Rapid Determination of OLEU Concentration in Dietary Supplements: Comparison with Total Phenol Content and Antioxidant Activity

The market for olive leaf dietary supplements is expanding rapidly and is valued at $437.15 million today. However, information on the control of these products is sketchy and the origin and variety of olives are rarely stated. The aim of this research was to validate a simple and rapid screening method for oleuropein determination in olive leaf dietary supplements. A matrix blank was prepared by removal of oleuropein from a mixture of dietary supplements and the matrix was then spiked with known concentrations to create a spiked matrix calibration curve in the range 5 - 40% oleuropein. Five replicate extractions and analyses of the matrix standards were carried out over 10 days. Precision was less than 6% RSD and linearity was demonstrated by the Fischer test. Extraction recovery was > 90% and there was a strong linear relationship between authentic and matrix standards. All tested products conformed to the label claim which was strongly correlated with total polyphenols measured by the Folin-Ciocalteau method. Antioxidant activity was measured by the DPPH assay and was found to be strongly correlated with total phenol content and oleuropein concentration.

Development of a multi-analysis model using an epithelial-fibroblast co-culture system as an alternative to animal testing

The evaluation of respiratory chemical substances has been mostly performed in animal tests (OECD TG 403, TG 412, TG 413, etc.). However, there have been ongoing discussions about the limited use of these inhalation toxicity tests due to differences in the anatomical structure of the respiratory tract, difficulty in exposure, laborious processes, and ethical reasons. Alternative animal testing methods that mimic in vivo testing are required. Therefore, in this study, we established a co-culture system composed of differentiated epithelial cells under an air-liquid interface (ALI) system in the apical part and fibroblasts in the basal part. This system was designed to mimic the wound-healing mechanism in the respiratory system. In addition, we developed a multi-analysis system that simultaneously performs toxicological and functional evaluations. Several individual assays were used sequentially in a multi-analysis model for pulmonary toxicity. Briefly, cytokine analysis, histology, and cilia motility were measured in the apical part, and cell migration and gel contraction assay were performed by exposing MRC-5 cells to the basal culture. First, human airway epithelial cells from bronchial (hAECB) were cultured under air-liquid interface (ALI) system conditions and validated pseudostratified epithelium by detecting differentiation-related epithelial markers using Transepithelial Electrical Resistance (TEER) measurement, Hematoxylin and Eosin (H&E) staining, and immunocytochemistry (ICC) staining. Afterward, the co-culture cells exposed to Transforming growth factor-beta 1 (TGF-β1), a key mediator of pulmonary fibrosis, induced significant toxicological responses such as cytotoxicity, cell migration, and gel contraction, which are wound-healing markers. In addition, cilia motility in epithelial cells was significantly decreased compared to control. Therefore, the multi-analysis model with a 3D epithelial-fibroblast co-culture system is expected to be useful in predicting pulmonary toxicity as a simple and efficient high-throughput screening method and as an alternative to animal testing.

Detection of the stimulant clobenzorex using voltammetry and screen-printed electrodes: A simple and fast screening method for application in seized samples and oral fluid of drivers

Clobenzorex (CBZ) is a stimulant drug, recognized for its anorectic potential, legally used in some countries for obesity treatment. However, CBZ is banned in much of the world and has been often used illegally by drivers needing to stay alert for extended periods. Therefore, the rapid identification of CBZ in forensic samples is of paramount importance for public health and safety. In this context, we introduce an innovative electroanalytical screening method for detecting CBZ in seized tablet samples and human oral fluid using voltammetry with a graphite screen-printed electrode (SPE-Gr). The electrochemical detection was optimized in phosphate buffer solution (0.1 mol L−1, pH 7.0) using square wave voltammetry (SWV). The SPE-Gr combined with SWV exhibited a good stability of the electrochemical responses for CBZ detection, with a relative standard deviation of less than 5% across different days (N = 5) and using different SPEs (N = 3). A linear detection range of 2.5–100.0 μmol/L (R2 = 0.992) was achieved, with a low limit of detection (LOD) of 0.32 μmol L−1. Interference studies with other illicit drugs and adulterants confirmed the selectivity of the proposed method for CBZ detection. In addition, the presence of CBZ in seized tablet samples and authentic oral fluids, collected from drivers, was detected and identified using the proposed method, which results were also confirmed by HPLC-MS. Consequently, integrating SPE-Gr with SWV offers a reliable, rapid, sensitive, selective, reproducible, and direct approach for the preliminary qualitative and quantitative analysis of CBZ in forensic contexts. Furthermore, the proposed method provides an efficient oral fluid test for CBZ screening in drivers under the influence of drugs.

Indigo production identifies hotspots in cytochrome P450 BM3 for diversifying aromatic hydroxylation.

Evolution of P450 BM3 is a topic of extensive research, but screening the various substrate/reaction combinations remains a time-consuming process. Indigo production has the potential to serve as a simple high-throughput method for reaction screening, as bacterial colonies expressing indigo (+) variants can be visually identified via their blue phenotype. Indigo (+) single variants, indigo (-) single variants and a combinatorial library, containing mutations that enable the blue phenotype, were screened for their ability to hydroxylate a panel of 12 aromatic compounds using the 4-aminoantipyrine colorimetric assay. Recombination of indigo (+) single variants to create a multiple-variant library is a particularly useful strategy, as all top performing P450 BM3 variants with high hydroxylation activity were either indigo (+) single variants or contained multiple substitutions. Furthermore, active variants, as determined using the 4-AAP assay, were further characterized and several variants were identified that gave more than 90% conversion with 1,3-dichlorobenzene and predominantly formed 2,6-dichlorophenol; other variants showed significant substrate selectivity. This supports the hypothesis that substitution at positions that enable the indigo (+) phenotype, or hotspot residues, is a general mechanism for increasing aromatic hydroxylation activity. Overall, this research demonstrates that indigo (+) single variants, identified via colorimetric colony-based screening, may be recombined to generate a multiply-substituted variant library containing many variants with high aromatic hydroxylation activity. The combination of colony-based screening and other screening assays greatly accelerates enzyme engineering, as readily-identified indigo (+) single variants can be recombined to create a library of active multiple variants without extensive screening of single variants.

Application study of apnea-hypopnea duration for assessing adult obstructive sleep apnea.

Obstructive sleep apnea (OSA) is a common sleep disordered breathing disorder, which can cause serious damage to multiple human systems. Although polysomnography (PSG) is the current gold standard for diagnosis, it is complex and expensive. Therefore, it is of great significance to find a simple, economical and rapid primary screening and diagnosis method to replace PSG for the diagnosis of OSA. The purpose of this study is to propose a new method for the diagnosis and classification of OSA, which is used to automatically detect the duration of sleep apnea hypopnea events (AHE), so as to estimate the ratio(S) of the total duration of all-night AHE to the total sleep time only based on the sound signal of sleep respiration, and to identify OSA. We performed PSG tests on participants and extracted relevant sleep breathing sound signal data. This study is carried out in two stages. In the first stage, the relevant PSG report data of eligible subjects were recorded, the total duration of AHE in each subject's data was extracted, and the S value was calculated to evaluate the severity of OSA. In the second stage, only the sleep breath sound signal data of the same batch of subjects were used for automatic detection, and the S value in the sleep breath sound signal was extracted, and the S value was compared with the PSG diagnosis results to calculate the accuracy of the experimental method. Among 225 subjects. Using PSG as the reference standard, the S value extracted from the PSG diagnostic data report can accurately diagnose OSA(accuracy rate 99.56%) and distinguish its severity (accuracy rate 95.11%). The accuracy of the S value detected in the sleep breathing sound signal in the diagnosis of severe OSA reached 100%. The results show that the experimental parameter S value is feasible in OSA diagnosis and classification. OSA can be identified and evaluated only by sleep breathing sounds. This method helps to simplify the diagnostic grading of traditional OSA and lays a foundation for the subsequent development of simple diagnostic grading equipment.

Rapid Identification of the Spruce Bark Beetle <i>Ips typographus</i> (Linnaeus) Basing on a New Amplification and Analysis Platform

Insects, one of the major disturbance agents, are regarded as a big challenge to forests. Bark beetles (Coleoptera: Curculionidae: Scolytinae) are among the most destructive pests around the world. The European spruce bark beetle <i>I. typographus </i>(Linnaeus) is considered the most dangerous species to mature spruce forests throughout Eurasia. In order to improve efficiency, accuracy, and operability of identification, a rapid, simple, highly sensitive and specific screening method is in urgent need. In this study, a rapid classification approach for <i>I. typographus</i> was established based on the enzyme-mediated duplex exponential amplification (EmDEA) amplification and analysis platform. The method development process consists of target gene selection, primer design, primer screening, and method validation. Parameter analysis demonstrated that this new method has a detection limit of 1.96×103 copies/μL, which is comparable to conventional molecular tools such as PCR. Stable repeatability and high specificity were confirmed by testing 5 samples of <i>I. typographus</i> and 4 related beetles. Besides, this screening protocol was easy to use, and could be completed in 30 min. With the advantage of isothermal amplification, this method could be further applied in non-laboratory scenarios such as port rapid screening and wild survey. This rapid screening method for <i>I. typographus</i> is believed to assist precise prediction and efficient prevention of exotic insect species.

A simple and practical fluorescence method for on-site screening and accurate detection of 4-hexylresorcinol in crustacean aquatic products

4-hexylresorcinol (4-HR), a natural compound renowned for its innate antibacterial and antioxidant properties, finds pervasive utilization in preventing browning and extending the shelf life of products such as shrimp and crab. The manuscript presents a novel method for expeditious screening and precise quantification of 4-HR in crustacean aquatic products, based on the reaction between 4-HR and dopamine to yield a strongly fluorescent product. The innovative method has remarkable sensitivity, strong anti-interference capabilities, simplicity, and rapidity, thereby facilitating not only on-site screening in just 7.5 min but also meticulous in-laboratory detection with enhanced precision. The fluorescence intensity has a linear relationship with 4-HR content in the range of 0–100 μg/g, with a detection limit of 0.006 μg/g. The proposed method has the potential to become a standard for determining 4-HR in crustacean aquatic products, addressing limitations of existing techniques like high-performance liquid chromatography, which are complex and costly. This methodology holds great promise in ensuring the safety of crustacean aquatic products.

DEVELOPMENT OF A PAPER-BASED DEVICE USING INDOXYL ACETATE AS A CHROMOGENIC SUBSTRATE FOR RAPID QUALITATIVE DETERMINATION OF LIPASE INHIBITOR

An improved paper-based device using indoxyl acetate as a chromogenic substrate was developed for rapid qualitative determination of lipase inhibitory activity. Colorless indoxyl acetate can be catalytically hydrolyzed by lipase to produce the blue-colored indigo dimer on the paper device. In the presence of a lipase inhibitor, enzyme activity diminishes, resulting in reduced hydrolysis of indoxyl acetate. Consequently, this leads to a decrease in the intensity of the blue coloration, which can be visually observed across a range of blue shades and analyzed using image analysis. Orlistat was used as the representative lipase inhibitor in the assay. The LODs obtained from visual detection and the image analysis were comparable. The paper-based device using indoxyl acetate for lipase inhibition assay was simple and convenient. It could be useful as a simple screening method for the detection of orlistat adulteration in weight loss supplements.

Isolation of aptamers with excellent cross-reactivity and specificity to sulfonamides towards a ratiometric fluorescent aptasensor for the detection of nine sulfonamides in seafood

Sulfonamides (SAs) is a class of antibiotics that extensively used for treating infectious diseases in livestock industries and aquaculture. Thus, it is urgent need to obtain the bio-receptor, which has excellent cross-reactivity and specificity to SAs, for developing high-throughput methods for the determination of multiple SAs even all commonly-used SAs, to realize the quick screening/detection of total SAs in animal-derived foods. We herein isolated several SAs-specific cross-reactive aptamers by using a library-immobilized SELEX with multi-SAs parallel selection strategy. Two of the isolated aptamers (Sul-01 and Sul-04) can specifically recognize and bind seven SAs respectively with higher binding affinity and no interference of non-sulfonamide antibiotics, and thus can be applied as bio-receptors for developing high-throughput aptasensors for the quick screening/detection of multiple SAs. By using the mixture of Sul-01 and Sul-04 as bio-receptor, a ratiometric fluorescent aptasensor was created for the quick detection of nine SAs including sulfamethoxydiazine (SMD), sulfapyridine (SPD), sulfaquinoxaline (SQ), sulfathiazole (ST), sulfamonomethoxine (SMM), sulfamerazine (SMR), sulfaguanidine (SG), sulfamethazine (SMZ) and sulfadiazine (SD) with a detection limit (LOD) of 0.10–0.50 μM, or total of above nine SAs with a LOD of 0.20 μM. The fluorescent aptasensor was successfully applied to detect each or total of SMD, SPD, SQ, ST, SMM, SMR, SG, SMZ and SD in fish samples with a recovery of 83 %–92 % and a relative standard deviation (RSD, n = 5) < 5 %. This study not only provided several promising bio-receptors for the development of diverse high-throughput aptasensors to achieve the quick screening of multiple SAs residues, but also provided a simple, stable and sensitive method for the quick screening of SMD, SPD, SQ, ST, SMM, SMR, SG, SMZ and SD in seafood.

Early fetal sex determination using a fluorescent DNA nanosensing platform capable of simultaneous detection of SRY and DYS14 sequences in cell-free fetal DNA

Early fetal sex determination is of crucial importance in the management of prenatal diagnosis of X-linked genetic abnormalities and congenital adrenal hyperplasia. The development of an efficient and simple method for high-sensitivity, affordable, and rapid screening of cell-free fetal DNA (cffDNA) is crucial for fetal sex determination in early pregnancy. In this study, single- and dual-fluorophore DNA biosensors based on multi-walled carbon nanotubes (MWCNT) were fabricated for the individual and simultaneous detection of the SRY gene and DYS14 marker in cffDNA obtained from maternal plasma samples. This nanosensing platform is based on the immobilization of single-stranded DNA (ssDNA) probes, labeled with ROX or FAM fluorophores, on MWCNT, resulting in the quenching of fluorescence emission in the absence of the targets. Upon the addition of the complementary target DNA (ctDNA) to the hybridization reaction, the fluorescence emission of fluorophore-labeled probes was significantly recovered to 79.5 % for ROX-labeled probes (i.e. SRY-specific probes), 81.5 % for FAM-labeled probes (i.e. DYS14-specific probes), and 65.9 % for dual-fluorophore biosensor compared to the quenching mode. The limit of detection (LOD) for ROX, and FAM was determined to be 4.5 nM, and 7.6 nM, respectively. For dual-color probes, LOD was found to be 5.4 (ROX) and 9.2 nM (FAM). Finally, the clinical applicability of the proposed method was confirmed through the detection of both biomarkers in maternal plasma samples, suggesting that the proposed nanosensing platform may be useful for the early detection of fetal sex using cffDNA.

Label-free voltammetric screening of human blood serum

The current study presents a comprehensive voltammetric investigation into the direct analysis of untreated human blood serum in a phosphate buffer at an unmodified, graphite electrode by means of voltammetry. By employing advanced square-wave voltammetry at an edge plane pyrolytic graphite electrode (EPPGE), the basic principles were established for developing a sensitive, fast, simple, and label-free method for the simultaneous screening of uric acid, bilirubin, and albumin analytes that are present in human blood serum and are quite essential for rapid medical diagnostics. The electrochemical protocol utilizes the specific structural patterns of the EPPGE, the inherent redox and adsorption properties of the analysed analytes, and the sensitivity and rapidity of the employed advanced voltammetric technique. The methodology has been successfully applied for quantification of the considered analytes in a series of samples of human blood serum and was compared with the standard methods used in a clinical biochemical laboratory. This novel method represents a significant advancement towards the development of point-of-care devices aimed at swiftly and simultaneously quantifying uric acid, bilirubin, and albumin levels in human serum.

Screening of aspiration pneumonia using the modified Mallampati classification tool in older adults.

Pneumonia is a major cause of morbidity and mortality in older adults. In the aging society, screening methods for predicting aspiration pneumonia are crucial for its prevention. Changes in the oropharyngeal morphology and hyoid bone position may increase the risk of aspiration pneumonia. This multicenter study aimed to investigate a simple and effective screening method for predicting dysphagia and aspiration pneumonia. Overall, 191 older adults (aged 65 years or older) were randomly sampled using the simple random sampling technique. Oropharyngeal morphology was assessed using the modified Mallampati classification, which reflects the size of the tongue in the oropharyngeal cavity. The hyoid position was measured as the distance between the menton and laryngeal prominence to evaluate aging-related changes in the muscles of the laryngopharynx. Dysphagia was assessed using the repetitive saliva swallowing test (RSST), which measures the number of swallowing movements in 30 seconds; dysphasia is defined as less than 3 swallowing movements in 30 seconds. The aspiration signs were assessed based on history of choking or coughing reflex during eating or drinking and medical history of pneumonia. The study findings revealed that the modified Mallampati classification was significantly correlated with a medical history of pneumonia. A higher incidence of pneumonia was evident in the lower Mallampati classification, which shows the smaller size of the tongue base in the oropharyngeal cavity. The results of this study suggest that the modified Mallampati classification may be a possible screening method to predict the occurrence of pneumonia.

The feasible screening of genuine fresh palmyrah toddy and sugar or rice toddy using near-infrared spectroscopy

The use of combination of Near-Infrared (NIR) absorption spectroscopic and k-mean multivariant statical cluster analysis as a screening tools for genuine fresh palmyrah toddy(G.F) and sugar (ATS) or rice toddy(ATS) is discussed. The quick and simple screening methods to ensure the authenticity of G.F is prime important to keep up its commercial value. Here we performed NIR spectroscopic analysis, k-mean multivariant analysis, and hierarchical cluster analysis to screen the G.F from ATR and ATS. For comparison, we performed chemical analysis and distinguished G.F from ATR and ATS. However, based on the NIR spectroscopic analysis together with the multivariant analysis G.F quickly screened from ATR and ATS. The plot of k-means cluster analysis and hierarchical cluster analysis shows three distinct clusters and it could be a useful tool to quickly screen the genuine toddy from artificial toddy.

SYBR Green I and DNA-modulated charge neutralization assembly of naked AuNPs for fast colorimetric sensing of Cd2+ in cosmetics

The involvement of cadmium in cosmetics results in inevitable exposure to our daily life. Therefore, it is of great significance to develop a simple and rapid method for fast screening of cadmium in cosmetics. Gold nanoparticles (AuNPs)-based colorimetric sensing offers a simple strategy for analytical detection, but the typical surface functionalization of AuNPs adds complexity to the overall detection. Nucleic acid dye-based charge neutralization offered a truly simple and fast approach for the assembly of AuNPs over the conventional salt-induced strategy. Herein, we developed a simple colorimetric sensing system for Cd2+, based on nucleic acid dye SYBR Green I (SG) and Cd2+ aptamer (Cd-2-1)-modulated charge neutralization assembly of naked AuNPs. The method rationale was based on the higher affinity of Cd2+ to Cd-2-1 DNA over SG, as well as the stable and fast charge neutralization-induced assembly of AuNPs by SG. The limit of detection (LOD) of the proposed method was 0.27 μM, which was substantially lower than the maximum permitted amount of Cd2+ in cosmetics regulated by the Chinese Food and Drug Administration (CFDA, 5 mg/kg, equivalent to 4.45 µM in our assay). Successful exploration of the proposed method was demonstrated for the detection of Cd2+ in cosmetics.

Development of a simple screening method for analyzing cereulide toxin in fried rice using liquid chromatography-tandem mass spectrometry.

The presence of cereulide, an emetic toxin produced by Bacillus cereus, in fried rice samples is critical evidence of food poisoning even in situations where B. cereus could not be detected. This study aims to develop a screening method for analyzing cereulide in fried rice using the QuEChERS procedure and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Cereulide was identified and quantified in fried rice samples using the QuEChERS extraction method and LC-MS/MS. The accuracies of the methods were determined by analyzing fortified blank samples at two concentrations (10 and 50µg/kg) conducted on three samples daily for five days. The QuEChERS procedure removed matrix compounds from fried rice. Characteristic MS/MS spectra enabled the identification of cereulide. As the matrix effects in seven fried rice samples were within ± 6%, an external solvent calibration curve could be used for quantification. This method exhibited good accuracy ranging from 88 to 89%. The relative standard deviations for both repeatability and intra-laboratory reproducibility were < 4%. These standard deviations satisfied the criteria of the Japanese validation guidelines for residues (MHLW 2010, Director Notice, Syoku-An No. 1224-1). The limit of quantification was 2μg/kg. The applicability of this method was confirmed using the analysis of cereulide in fried rice samples incubated with emetic Bacillus cereus. The QuEChERS extraction procedure described herein showed substantial promise as a reliable screening tool for cereulide in fried rice sample.

Characteristic SNPs defining the major multidrug-resistant Mycobacterium tuberculosis clusters identified by EuSeqMyTB to support routine surveillance, EU/EEA, 2017 to 2019.

BackgroundThe EUSeqMyTB project, conducted in 2020, used whole genome sequencing (WGS) for surveillance of drug-resistant Mycobacterium tuberculosis in the European Union/European Economic Area (EU/EEA) and identified 56 internationally clustered multidrug-resistant (MDR) tuberculosis (TB) clones.AimWe aimed to define and establish a rapid and computationally simple screening method to identify probable members of the main cross-border MDR-TB clusters in WGS data to facilitate their identification and track their future spread.MethodsWe screened 34 of the larger cross-border clusters identified in the EuSeqMyTB pilot study (2017-19) for characteristic single nucleotide polymorphism (SNP) signatures that could identify and define members of each cluster. We also linked this analysis with published clusters identified in previous studies and identified more distant genetic relationships between some of the current clusters.ResultsA panel of 30 characteristic SNPs is presented that can be used as an initial (routine) screen for members of each cluster. For four of the clusters, no unique defining SNP could be identified; three of these are closely related (within approximately 20 SNPs) to one or more other clusters and likely represent a single established MDR-TB clade composed of multiple recent subclusters derived from the previously described ECDC0002 cluster.ConclusionThe identified SNP signatures can be integrated into routine pipelines and contribute to the more effective monitoring, rapid and widespread screening for TB. This SNP panel will also support accurate communication between laboratories about previously identified internationally transmitted MDR-TB genotypes.

Geriatric Nutritional Risk Index and First-Year Mortality in Incident Hemodialysis Patients.

The Geriatric Nutritional Risk Index is a simple nutritional screening method, and this study aimed to investigate the association between the initial Geriatric Nutritional Risk Index and all-cause mortality in incident patients in the first year after the initiation of hemodialysis. This study is a retrospective cohort study and used the Korean Renal Data System database. Patients who were eligible for Geriatric Nutritional Risk Index assessment and underwent hemodialysis from January 2016 to December 2019 were included. The primary outcome was all-cause mortality, and outcome evaluation was performed in December 2020. A Cox proportional hazard model was used to analyze the association between the Geriatric Nutritional Risk Index and mortality. A total of 10,545 patients were included, and the mean age was 63.9 ± 3.7 years. The patients were divided into four groups by the quartile of the Geriatric Nutritional Risk Index with a mean value of 96.2 ± 8.2. During the study period, 545 (5.2%) deaths occurred. The surviving patients had higher Geriatric Nutritional Risk Index values than ones who died in the first year of hemodialysis initiation (96.6 ± 7.5 vs. 88.2 ± 9.3, p < 0.001). Quartile 1 (Geriatric Nutritional Risk Index < 91.8) showed a significantly increased risk of all-cause (Hazard Ratio: 2.56; 95% Confidence Interval: 2.13-3.09; p < 0.001) and cardiovascular mortality (Hazard Ratio: 22.29; 95% Confidence Interval: 1.71- 3.08; p < 0.001) at the first year in comparison with Quartile 4 (Geriatric Nutritional Risk Index ≥ 101.3). In areas under the receiver-operating characteristic curves of all-cause mortality, the Geriatric Nutritional Risk Index model improved predictive values, compared to the baseline model. The area with the Geriatric Nutritional Risk Index model was significantly higher than the one with a model including albumin or body mass index (p < 0.001). These findings suggest that a low Geriatric Nutritional Risk Index (<91.8) is associated with first-year all-cause and cardiovascular mortality in patients who start hemodialysis and may be a useful and reproducible tool for assessing prognoses in this population.

Dual-FRET aptasensor for rapid screening of Ochratoxin A in food samples

Simple, low cost, and sensitive OTA screening method is important for food safety control. The discovery of the OTA aptamer enabled the development of various aptasensors, but the structural change caused by target binding is not appreciable enough, thus limiting the sensitivity. The introduction of various nanomateirals could amplify the structure change, but such aptasensors are difficult to be standardized, thus is not suitable for screening analysis. Herein, we proposed a full DNA-based dual-FRET aptasensor, in which the aptamer was rigidified to amplify the OTA-induced structure change. Meanwhile, a dual FRET strategy was employed to increase the OTA detection sensitivity. Upon both experimental and theoretical selection, aptamer OBA33 was selected, leading to a detection limit of 2.1 nM that is lower than the limit set by Chinese National Food Safety Standard (12 nM), thus is appealing for screening of potential OTA-positive cases in a large number of rice samples. To facilitate rapid screening analysis, a mini 3D-printed sensor device was constructed by integrating LED excitation, cellphone camera image taking, and RGB extraction. Due to the technological maturity of DNA production, the proposed aptasensor could be easily standardized for fast OTA screening analysis (15 min).

Combination Screening of a Naïve Antibody Library Using E. coli Display and Single-Step Colony Assay

The use of single-domain camelid antibodies, termed VHHs or nanobodies, has found increasing application in diagnosis, pharmaceutical development, and research because of their superior properties, such as small size, elevated stability, high water solubility, and excellent affinity for the antigen. Antigen-specific VHHs are generated by screening VHH display libraries via bio-panning. However, the bio-panning step needs to be repeated multiple times, which is time-consuming and laborious. Here, we developed a simple and rapid screening method that combined Escherichia coli display and a single-step colony assay to successfully identify positive clones from a naïve VHH library. The library was constructed from peripheral blood mononuclear cells of alpaca, and VHHs were displayed on the surface of E. coli using the inverse autotransporter intimin. Libraries enriched by magnetic cell sorting were screened directly using a single-step colony assay. Colonies formed on the hydrophilic filter and antigen-coated membrane. The expression of VHHs was induced, and those bound to the antigen on the membrane were detected as positive clones. Screening and identification of positive clones required only two days, which saves considerable time and resources compared to existing protocols.