Simple Screening Method Research Articles

Development of a Simple Mechanical Screening Method for Predicting the Feedability of a Pharmaceutical FDM 3D Printing Filament

PurposeThe filament-based feeding mechanism employed by the majority of fused deposition modelling (FDM) 3D printers dictates that the materials must have very specific mechanical characteristics. Without a suitable mechanical profile, the filament can cause blockages in the printer. The purpose of this study was to develop a method to screen the mechanical properties of pharmaceutically-relevant, hot-melt extruded filaments to predetermine their suitability for FDM.MethodsA texture analyzer was used to simulate the forces a filament is subjected to inside the printer. The texture analyzer produced a force-distance curve referred to as the flexibility profile. Principal Component Analysis and Correlation Analysis statistical methods were then used to compare the flexibility profiles of commercial filaments to in-house made filaments.ResultsPrincipal component analysis showed clearly separated clustering of filaments that suffer from mechanical defects versus filaments which are suitable for printing. Correlation scores likewise showed significantly greater values with feedable filaments than their mechanically deficient counterparts.ConclusionThe screening method developed in this study showed, with statistical significance and reproducibility, the ability to predetermine the feedability of extruded filaments into an FDM printer.

A simple and cost-effective method for screening of CRISPR/Cas9-induced homozygous/biallelic mutants

BackgroundThe CRISPR/Cas9 system is being used for genome editing purposes by many research groups in multiple plant species. Traditional sequencing methods to identify homozygous mutants are time-consuming, laborious and expensive.ResultsWe have developed a method to screen CRISPR/Cas9-induced mutants through Mutation Sites Based Specific Primers Polymerase Chain Reaction (MSBSP-PCR). The MSBSP-PCR method was successfully used to identify homozygous/biallelic mutants in Nicotiana tabacum and Arabidopsis thaliana, and we speculate that it can be used for the identification of CRISPR/Cas9-induced mutants in other plant species. Compared to traditional sequencing methods, MSBSP-PCR is simpler, faster and cheaper.ConclusionsThe MSBSP-PCR method is simple to implement and can save time and cost in the screening of CRISPR/Cas9-induced homozygous/biallelic mutants.

A Simple and Portable Screening Method for Adulterated Olive Oils Using the Hand-Held FTIR Spectrometer and Chemometrics Tools.

This research provide a rapid and automatic detection method for olive oils adulterated with other cheaper vegetable oils. An oil sample can be measured directly within one minute, and the hand-held instrument can be used anywhere needed.

Nagina 22 mutants tolerant or sensitive to low P in field show contrasting response to double P in hydroponics and pots

ABSTRACTA simple screening method is needed to identify rice genotypes tolerant to low phosphorus (P) in soil. Nagina 22 (N22) mutants were classified as gain of function (gof) and loss of function (lof) for tolerance to very low P (soil Olsen P 2.01 mg kg−1). Two gof and two lof mutants were grown in hydroponics and in pot experiment at three P levels (-P, +P and +2P). Comparing response at +P and +2P in hydroponics we found that shoot and root dry weight were significantly less in gof and significantly more in lof in +2P. In pots with soil, tiller number and yield/plant was 3 fold less in gof but 2.5 to 3 fold more in lof and N22 in +2P compared to +P. That 2P can be used to identify low-P tolerant genotypes was validated using 3 low-P tolerant and 3 sensitive varieties whose response to low P soil is well documented. Both shoot and root dry weight was significantly less in +2P than in +P in tolerant and significantly more in sensitive genotypes. Thus screening in hydroponics in +2P can help identify low-P- tolerant genotypes easily and rapidly avoiding field screening.

Combining Promiscuous Acyl-CoA Oxidase and Enoyl-CoA Carboxylase/Reductases for Atypical Polyketide Extender Unit Biosynthesis

The incorporation of different extender units generates structural diversity in polyketides. There is significant interest in engineering substrate specificity of polyketide synthases (PKSs) to changetheir chemical structure. Efforts to change extenderunit selectivity are hindered by the lack of simple screening methods and easily available atypical extender units. Here, we present a chemo-biosyntheticstrategy that employs biocatalytic proofreading and allows access to a large variety of extender units. First, saturated acids are chemically coupled to free coenzyme A (CoA). The corresponding acyl-CoAs are then converted to alkylmalonyl-CoAs in a "one-pot" reaction through the combinedaction of an acyl-CoA oxidase and enoyl-CoA carboxylase/reductase. We synthesized six different extender units and used them in invitro competition screens to investigate active site residues conferring extender unit selectivity. Our results show the importance of an uncharacterized glutamine in extender unit selectivity and openthe possibility for comprehensive studies on extender incorporation in PKSs.

A Machine Learning Application Based in Random Forest for Integrating Mass Spectrometry-Based Metabolomic Data: A Simple Screening Method for Patients With Zika Virus.

Recent Zika outbreaks in South America, accompanied by unexpectedly severe clinical complications have brought much interest in fast and reliable screening methods for ZIKV (Zika virus) identification. Reverse-transcriptase polymerase chain reaction (RT-PCR) is currently the method of choice to detect ZIKV in biological samples. This approach, nonetheless, demands a considerable amount of time and resources such as kits and reagents that, in endemic areas, may result in a substantial financial burden over affected individuals and health services veering away from RT-PCR analysis. This study presents a powerful combination of high-resolution mass spectrometry and a machine-learning prediction model for data analysis to assess the existence of ZIKV infection across a series of patients that bear similar symptomatic conditions, but not necessarily are infected with the disease. By using mass spectrometric data that are inputted with the developed decision-making algorithm, we were able to provide a set of features that work as a “fingerprint” for this specific pathophysiological condition, even after the acute phase of infection. Since both mass spectrometry and machine learning approaches are well-established and have largely utilized tools within their respective fields, this combination of methods emerges as a distinct alternative for clinical applications, providing a diagnostic screening—faster and more accurate—with improved cost-effectiveness when compared to existing technologies.

STARD-rapid screening for the 6 most common G6PD gene mutations in the Chinese population using the amplification refractory mutation system combined with melting curve analysis.

Dot-blot hybridization and high-resolution melting curve methods are used to detect G6PD gene mutations; however, the performance and throughput limitations of these methods hinder their use for screening large populations. For simple screening, we developed a novel approach called “Amplification Refractory Mutation System combined with Melting Curve Analysis (ARMS-MC),” which enables rapid and batch-based detection of the 6 most common G6PD mutations.In this method, we established 4 PCR reaction systems that can be used to detect the 6 most common G6PD mutations (c.95A>G, c.392G>T, c.871G>A, c.1024C>T, c.1376G>T, and c.1388G>A) in the Chinese population.The ARMS-MC method was evaluated with 174 cases of clinical G6PD-deficient samples, and the results were verified by direct sequencing at G6PD gene exons. The results showed that 170 samples had ≥1 of the 6 mutations, which accounted for 97.70% of all mutations. These results were consistent with the results of direct sequencing with 100% accuracy and specificity. Sequencing validation revealed other mutations in the 4 samples in which no mutation was detected by the ARMS-MC method.ARMS-MC provides a rapid, simple, inexpensive, and accurate screening method for detecting the most common G6PD mutations in Chinese people.

Association between braced curve behavior by pubertal growth peak and bracing effectiveness in female idiopathic scoliosis: a longitudinal cohort study

BackgroundPre-pubertal idiopathic scoliosis (IS) is associated with high risk of bracing ineffectiveness. Integrated multidimensional maturity assessments are useful but complex to predict the high-risk occurrence of curve progression. This study is designed to provide a simple screening method for brace effectiveness by determining whether or not the braced curve behavior at growth spurt, being defined as variations in Cobb angle velocity (AV) at peak height velocity (PHV), can be a new factor predictive of brace outcome prescribed before PHV.MethodsThis is a retrospective study of a series of 35 IS girls with simplified skeletal maturity score no more than 3 at initiation of bracing treatment and followed up through the growth spurt until brace weaning or surgery. Serial Cobb angle and maturity indicators involving height velocity, Risser sign, triradiate cartilage, simplified skeletal maturity score and distal radius and ulna classification were assessed and patients were stratified into either a positive or negative category based on a positive or negative value of AV at PHV. Comparisons were made between the positive and negative AV groups, as well as the failed and successful bracing groups, using independent sample T test and crosstab analysis. Logistic regression analysis was used to identify the predictive factors of failed brace treatment.ResultsBrace treatment prescribed before PHV was found to have an overall failure rate of 57.1% and a surgical rate of 45.7%. Negative AV at PHV accounting for 54.3% of the recruited patients were associated with lower brace failure rate (36.8% vs. 81.2%, p = 0.016) and surgical rate (21.1% vs. 75.0%, p = 0.002). Patients in the failed bracing group showed higher ratio of thoracic curve (80.0% vs. 26.7%,p = 0.002) and higher AV at growth peak (2.3 ± 9.1 vs. -6.5 ± 11.4°/yrs., p = 0.016). The logistic regression analysis revealed that positive AV at PHV (OR = 9.268, 95% CI = 1.279–67.137, p = 0.028) and thoracic curve type (OR = 13.391, 95% CI = 2.006–89.412, p = 0.007) were strong predictive factors of ineffective brace treatment initiated before PHV.ConclusionsSustained curve correction following bracing despite early onset and rapid pubertal growth was strongly predictive of effective brace control of scoliosis.

Greedy forward regression for variable screening

SummaryIn the ultra‐high dimensional setting, two popular variable screening methods with the desirable sure screening property are sure independence screening (SIS) and forward regression (FR). Both are classical variable screening methods, and recently have attracted greater attention under high‐dimensional data analysis. We consider a new and simple screening method that incorporates multiple predictors at each step of forward regression, with decisions on which variables to incorporate based on the same criterion. If only one step is carried out, the new procedure reduces to SIS. Thus it can be regarded as a generalisation and unification of FR and SIS. More importantly, it preserves the sure screening property and has computational complexity similar to FR at each step, yet it can discover the relevant covariates in fewer steps. Thus it reduces the computational burden of FR drastically while retaining the advantages of the latter over SIS. Furthermore, we show that it can find all the true variables if the number of steps taken is the same as the correct model size, which is a new theoretical result even for the original FR. An extensive simulation study and application to two real data examples demonstrate excellent performance of the proposed method.

Identification of Dermatoglyphic Patterns in Parents of Children with Cystic Fibrosis

Background Dermatoglyphics could assist in the diagnosis of congenital abnormalities. The aim of this study was to identify the dermatoglyphic patterns (finger print pattern type, total ridge count of each finger, a-b ridge count, and articulotrochanteric distance [ATD angles]) in the parents of cystic fibrosis children. Materials and Methods We recruited 75 parents of children with cystic fibrosis for the study group and 341 parents for the control group. We recorded finger print pattern type, total ridge count (TRC), a-b ridge count, and ATD angles of all participants. Then we identified any asymmetry between the right and left hands of each person and characteristics of parents in two genders. Chi-square analysis, Mann-Whitney U test, and Fisher's exact test were used for data analysis. Results We observed significant differences in a-b ridge count on the right hand (P=0.02), and mean total ridge count on the right digit I (P=0.05), right digit IV (P=0.03), and right digit V in the fathers of children with cystic fibrosis compared to the control group(P=0.02). Conclusion According to the results, we suggest that the dermatoglyphic traits of parents could be used as a simple, appropriate, and supplementary screening method in the diagnosis of children with CF. Nevertheless, we need lager studies to precisely confirm that dermatoglyphics is a reliable method in the diagnosis of CF.

N_LyST: a simple and rapid screening test for Lynch syndrome

AimsWe sought to use PCR followed by high-resolution melting analysis to develop a single closed-tube screening panel to screen for Lynch syndrome. This comprises tests for microsatellite instability (MSI), MLH1...

Rapid Screening of Sulfur Amino Acids in Human Plasma by Ultra Performance Liquid Chromatography-tandem Mass Spectrometry for Diagnosis of Metabolic Disorder

A rapid and simple screening method was developed for the simultaneous analysis of 6 sulfur-containing amino acids from human plasma at ng level. The procedure involves simple protein precipitation followed by direct analysis using UPLC-MS/MS. Calibration curves showed an excellent linear relationship with coefficients of determination (r 2 ) of 0.9989-0.9998. LOD and LOQ were between 1-50 ng/mL and 10-100 ng/mL, respectively. When sulfur amino acids spiked into plasma sample, excellent linearity of detection response was demonstrated over the range between 10-10,000 ng/mL. This new analytical method is suitable for simultaneous screening of large number of samples in clinical application and metabolomics research.

Utilizing a Combination of TGA and GC-MS to Estimate Health-Based Risks from Off-Gassed Volatile Compounds

Off-gassed compounds emitted from various materials can, in some instances, present health risks. In order to assess the potential health risks, off-gassed compounds must be identified, quantified, and evaluated relative to known health-based exposure guidance levels. We present a simple screening method for doing this that combines thermogravimetric analysis with thermal desorption–gas chromatography–mass spectrometry. The masses of particular volatile compounds are estimated over the course of a short-term, acute exposure. Assumptions (or measurements) of a room size can be used to convert these mass estimates to estimated concentrations, which can then be compared with readily available health-based exposure thresholds.

Colorimetric ELISA for ochratoxin A detection based on the urease-induced metallization of gold nanoflowers

This study reports a novel enzyme-induced metallization plasmonic enzyme-linked immunosorbent assay (pELISA) for ultrasensitive detection of ochratoxin A (OTA) in rice, corn, wheat, and white wine samples. OTA-labeled urease was used as competing antigen to hydrolyze urea into ammonia. Silver ions were reduced by the formyl group from glucose to generate a silver shell on the surface of gold nanoflowers (33 nm, AuNFs) in the presence of ammonia molecules. The color of the solution changed from blue to brownish red. Various parameters that influenced the sensitivity of colorimetric pELISA were investigated and optimized. Under the optimized conditions, the colorimetric pELISA exhibited a high sensitivity for qualitative detection of OTA by the naked eye with a cutoff limit of 40 pg/mL, and a favorable linear range of 5.0–640 pg/mL for quantitative detection of OTA with a limit of detection at 8.205 pg/mL. These values are 15.6- and 14.3-folds lower than those of horseradish peroxidase (HRP)-based ELISA. The method also showed excellent specificity against four other mycotoxins including deoxynivalenol, zearalenone, fumonisin B1, and aflatoxin B1. Moreover, the recoveries for OTA-spiked rice, corn, wheat, and white wine samples ranged from 81.5% to 106%, with coefficient of variation ranging from 6.13% to 18.7%. These results showed a good agreement with those obtained by an ultra-performance liquid chromatography-fluorescence detector (UPLC-FLD) method. Hence, the proposed method exhibited excellent robustness and reliability for quantitative detection of OTA in different food samples. This work provides a simple, sensitive, robust, and high-throughput screening method for qualitative or quantitative detection of mycotoxins or other pollutants in food safety monitoring.

A Simple Surface-Enhanced Raman Spectroscopic Method for on-Site Screening of Tetracycline Residue in Whole Milk.

Therapeutic and subtherapeutic use of veterinary drugs has increased the risk of residue contamination in animal food products. Antibiotics such as tetracycline are used for mastitis treatment of lactating cows. Milk expressed from treated cows before the withdrawal period has elapsed may contain tetracycline residue. This study developed a simple surface-enhanced Raman spectroscopic (SERS) method for on-site screening of tetracycline residue in milk and water. Six batches of silver colloid nanoparticles were prepared for surface enhancement measurement. Milk-tetracycline and water-tetracycline solutions were prepared at seven concentration levels (1000, 500, 100, 10, 1, 0.1, and 0.01 ppm) and spiked with silver colloid nanoparticles. A 785 nm Raman spectroscopic system was used for spectral measurement. Tetracycline vibrational modes were observed at 1285, 1317 and 1632 cm−1 in water-tetracycline solutions and 1322 and 1621 cm−1 (shifted from 1317 and 1632 cm−1, respectively) in milk-tetracycline solutions. Tetracycline residue concentration as low as 0.01 ppm was detected in both the solutions. The peak intensities at 1285 and 1322 cm−1 were used to estimate the tetracycline concentrations in water and milk with correlation coefficients of 0.92 for water and 0.88 for milk. Results indicate that this SERS method is a potential tool that can be used on-site at field production for qualitative and quantitative detection of tetracycline residues.

Simple In Vitro Assay To Evaluate the Incorporation Efficiency of Ribonucleotide Analog 5'-Triphosphates into RNA by Human Mitochondrial DNA-Dependent RNA Polymerase.

ABSTRACTThere is a growing body of evidence suggesting that some ribonucleoside/ribonucleotide analogs may be incorporated into mitochondrial RNA by human mitochondrial DNA-dependent RNA polymerase (POLRMT) and disrupt mitochondrial RNA synthesis. An assessment of the incorporation efficiency of a ribonucleotide analog 5′-triphosphate by POLRMT may be used to evaluate the potential mitochondrial toxicity of the analog early in the development process. In this report, we provide a simple method to prepare active recombinant POLRMT. A robust in vitro nonradioactive primer extension assay was developed to assay the incorporation efficiency of ribonucleotide analog 5′-triphosphates. Our results show that many ribonucleotide analogs, including some antiviral compounds currently in various preclinical or clinical development stages, can be incorporated into newly synthesized RNA by POLRMT and that the incorporation of some of them can lead to chain termination. The discrimination (D) values of ribonucleotide analog 5′-triphosphates over those of natural ribonucleotide triphosphates (rNTPs) were measured to evaluate the incorporation efficiency of the ribonucleotide analog 5′-triphosphates by POLRMT. The discrimination values of natural rNTPs under the condition of misincorporation by POLRMT were used as a reference to evaluate the potential mitochondrial toxicity of ribonucleotide analogs. We propose the following criteria for the potential mitochondrial toxicity of ribonucleotide analogs based on D values: a safe compound has a D value of >105; a potentially toxic compound has a D value of >104 but <105; and a toxic compound has a D value of <104. This report provides a simple screening method that should assist investigators in designing ribonucleoside-based drugs having lower mitochondrial toxicity.

Complexity in internal medicine wards: A novel screening method and implications for management.

Complexity is increasingly recognized as a critical variable in health care. However, there is still lack of practical tools to assess it and tackle the challenges that stem from it, particularly within hospitals. To validate a simple novel screening method based on both objective and subjective criteria to identify patients with clinically complex hospitalization events. To evaluate the prevalence of patients with complex events, identify their features, and compare them with those of the other patients and to those of patients with multimorbidities. We monitored the level of complexity of the hospitalization events of 240 patients admitted to an internal medicine ward in Tuscany over the course of 56days. We compared the demographic features, the length of stay, and the prognosis of patients with and without complex events. Sixty-nine patients (28.8% of the sample) had a complex episode during their stay, and 115 (47.9%) had phases of low complexity. Patients with complex episodes were younger and more comorbid than patients without. They stayed longer in-hospital (+4.5days; 95% CI: 2.5-6.5) and had higher mortality (OR: 24.93; 95% CI: 6.97-171.63) and a lower probability of home discharge (OR: 0.25; 95% CI: 0.13-0.48). The results show that using a simple screening method is possible to identify complex patients within IM wards and that every day, about one-third of the patients are complex. The results are discussed in implications for the dynamic management of patients with complex and simple phases during hospitalization.

Screening of sulfonamides in waters based on miniaturized solid phase extraction and microplate spectrophotometric detection

A simple and cost-effective screening method for determination of sulfonamides in water is proposed.

Functional-Based Screening Methods for Detecting Esterase and Lipase Activity Against Multiple Substrates.

Functional screens have been extensively used for searching native enzymes or mutant variants in clone libraries. Esterases and lipases are the most retrieved enzymes, because they are within the more demanded industrial enzymes and because a number of simple and generic screening methods can be applied for their screen. Here, we describe the use of a generic pH indicator assay protocol which unambiguously allows detecting in high-throughput manner esterase and lipase activity and quantifying specific activities using an ester concentration above 0.5mM. The described method is simple and generic to allow the selection of esterases and lipases targeting desired esters.

Simple Method of Screening for Frailty in Older Adults Using a Chronometer and Tape Measure in Clinic.

Detecting frailty in older adults scheduled for surgery is important to predict the occurrence of adverse outcomes, but because of its complexity, frailty screening is not commonly performed. The objective of the current study was to assess whether frailty can be screened for using automatically measured usual gait speed (UGS) and mid-arm circumference (MAC) in the outpatient clinic. Prospective, cross-sectional study. Geriatric center of a tertiary hospital. Outpatients aged 65 and older (N = 113). Frailty status was evaluated according to a multidimensional frailty score (MFS) using a comprehensive geriatric assessment, and participants were classified into 5 categories. UGS was evaluated by having participants walk through the clinic using an automated laser-gated chronometer. MAC was recorded using a tape measure on a blood pressure cuff. Correlations between these two physical measurements and MFS were assessed. The mean age of the 93 participants who successfully underwent UGS evaluation was 75.8 ± 4.7; 35 were male. In this population, the mean Charlson Comorbidity Index was 2.2 ± 1.4, mean MFS was 4.1 ± 2.0, and 20 participants were considered to be at high risk of experiencing adverse outcomes. Mean UGS was 0.75 ± 0.16 m/s, and mean MAC was 31.2 ± 1.9 cm); both physical parameters were correlated with MFS (UGS: standardized beta = -0.420, P < .001; MAC: standardized beta = -0.457, P < .001). Using UGS and MFS, the area under curve of receiver operating curve for determining which participants were at high risk of experiencing adverse outcomes was 0.809 (P < .001). UGS and MAC are viable methods of clinically screening for frailty.