A sensitized ratiometric fluorescence probe based on N/S doped carbon dots and mercaptoacetic acid capped CdTe quantum dots for the highly selective detection of multiple tetracycline antibiotics in food.

A ratiometric fluorescent probe based on N/S doped carbon dots (N/S-CQDs) and mercaptoacetic acid capped CdTe quantum dots (TGA-CdTe QDs) with sensitized and self-calibration functions was constructed to sensitively detect multiple tetracycline antibiotics (TCs). N/S-CQDs could attach stably to TGA-CdTe QDs and form a new composite ratiometric fluorescent probe that had a more than tenfold increase in sensitivity to TCs compared with each single QD. The probe could detect four common TCs as the color of the probe changed from bright red to dark red, and the limit of detection (LOD) was 1.47 × 10-2-1.78 × 10-2 mg/L. Practical applications of the probe in food and urine were also verified with recovery rates of 95.21%-104.97%. Due to the abundant spectral fingerprints provided by both QDs, this novel probe could accurately recognize not only different single TCs but also mixed TC samples even in actual samples combined with chemometrics.

Association of Social-Cognitive Factors with Individual Preventive Behaviors of COVID-19 among a Mixed-Sample of Older Adults from China and Germany.

Identifying modifiable correlates of older adults' preventive behaviors is contributable to the prevention of the COVID-19 and future pandemics. This study aimed to examine the associations of social-cognitive factors (motivational and volitional factors) with three preventive behaviors (hand washing, facemask wearing, and physical distancing) in a mixed sample of older adults from China and Germany and to evaluate the moderating effects of countries. A total of 578 older adults (356 Chinese and 222 German) completed the online cross-sectional study. The questionnaire included demographics, three preventive behaviors before and during the pandemic, motivational factors (health knowledge, attitude, subjective norm, risk perception, motivational self-efficacy (MSE), intention), and volitional factors (volitional self-efficacy (VSE), planning, and self-monitoring) of preventive behaviors. Results showed that most social-cognitive factors were associated with three behaviors with small-to-moderate effect sizes (f2 = 0.02 to 0.17), controlled for demographics and past behaviors. Country moderated five associations, including VSE and hand washing, self-monitoring and facemask wearing, MSE and physical distancing, VSE and physical distancing, and planning and physical distancing. Findings underline the generic importance of modifiable factors and give new insights to future intervention and policymaking. Country-related mechanisms should be considered when aiming to learn from other countries about the promotion of preventive behaviors.

FMixCutMatch for semi-supervised deep learning.

Mixed sample augmentation (MSA) has witnessed great success in the research area of semi-supervised learning (SSL) and is performed by mixing two training samples as an augmentation strategy to effectively smooth the training space. Following the insights on the efficacy of cut-mix in particular, we propose FMixCut, an MSA that combines Fourier space-based data mixing (FMix) and the proposed Fourier space-based data cutting (FCut) for labeled and unlabeled data augmentation. Specifically, for the SSL task, our approach first generates soft pseudo-labels using the model's previous predictions. The model is then trained to penalize the outputs of the FMix-generated samples so that they are consistent with their mixed soft pseudo-labels. In addition, we propose to use FCut, a new Cutout-based data augmentation strategy that adopts the two masked sample pairs from FMix for weighted cross-entropy minimization. Furthermore, by implementing two regularization techniques, namely, batch label distribution entropy maximization and sample confidence entropy minimization, we further boost the training efficiency. Finally, we introduce a dynamic labeled-unlabeled data mixing (DDM) strategy to further accelerate the convergence of the model. Combining the above process, we finally call our SSL approach as "FMixCutMatch", in short FMCmatch. As a result, the proposed FMCmatch achieves state-of-the-art performance on CIFAR-10/100, SVHN and Mini-Imagenet across a variety of SSL conditions with the CNN-13, WRN-28-2 and ResNet-18 networks. In particular, our method achieves a 4.54% test error on CIFAR-10 with 4K labels under the CNN-13 and a 41.25% Top-1 test error on Mini-Imagenet with 10K labels under the ResNet-18. Our codes for reproducing these results are publicly available at https://github.com/biuyq/FMixCutMatch.

Discrimination of haplotype in mitochondrial DNA mixtures using LNA-mediated PCR clamping.

Locked nucleic acid (LNA) has been widely used for various genetic analyses, and has many benefits, in terms of the specificity or sensitivity of amplification, because LNA-containing primers/probes form more stable duplexes with template DNA than probes lacking LNA. Here, we developed a new method for discriminating HV1 haplotypes from mitochondrial DNA (mtDNA) mixtures by applying PCR clamping using LNA. PCR clamping is based on the selective inhibition of amplification using LNA-containing probes, which can discriminate single-nucleotide differences. Before designing probes, we selected 171 sequences with single-nucleotide variations from the HV1 region, and evaluated the specificity of LNA-containing probes for them by predicting Tm values. The differences of Tm between mismatched and exactly matched probe-template duplexes depended markedly on the type of LNA nucleotides for discriminating single-nucleotide differences, and the cytosine LNA nucleotide at the site of variations in the probes was most effective to discriminate these differences. For mixture analysis, each probe targeted one or two variations (16209C, 16217C, 16257A/16261T, 16297C/16298C, 16304C, 16362C, or 16362T) that are particularly common in the Japanese population, and seven designed probes completely inhibited the amplification of exactly matched templates. We prepared mixed samples by mixing DNA from two individuals at a ratio of 1:9, 1:4, 1:1, 4:1, or 9:1, and then performed Sanger sequencing analysis after PCR clamping with each probe. Our method distinguished each haplotype at lower ratios from two-person mixtures, and enabled sensitive detection at 12 pg of total DNA including 600 copies of mtDNA. Moreover, we analyzed three-person mixtures with representative sequences, and detected the minor haplotype of one individual present at a rate of 10% by adding two selected probes. The ability to discriminate haplotypes in mixed samples by using LNA-mediated PCR clamping indicates the potential value of mtDNA analysis in criminal investigations.

The evaluation and validation of Phadebas® paper as a presumptive screening tool for saliva on forensic exhibits.

The Phadebas® Forensic Press Test is routinely used for the detection of saliva. However, assessment of the use of Phadebas® paper for this purpose has not been studied extensively. The suitability of Phadebas® paper as a presumptive screening tool for saliva on forensic exhibits, was investigated by analysing the following: (1) sensitivity, (2) specificity, (3) effects of temperature on sensitivity and specificity, (4) detection of saliva in mixed body fluid samples, and (5) influence of substrate porosity. The results of this study demonstrated that Phadebas® paper is more sensitive to α-amylase activity and less specific for saliva than previously reported. The use of an examination temperature of 37°C had no effect on sensitivity, but increased the incidence of cross-reactivity with other forensically relevant body fluid stains. Blood, urine and vaginal secretions can inhibit the detection of α-amylase activity with Phadebas® paper in mixed stains of saliva and body fluid. Substrate porosity is a weak predictor for the time taken for a saliva stain to achieve a strong positive result on Phadebas® paper. Overall, this study demonstrated that the Phadebas® Forensic Press Test has limitations as a presumptive test for the accurate identification of saliva.

Next generation sequencing-based precision STR genotyping of mixed samples / 中国法医学杂志

Objective To genotype mixed samples with next generation sequencing and evaluate its prospects in forensic DNA application. Methods Three mixed biological samples from rapes cases and their reference samples were collected. DNA was extracted using the MagAttract M48 DNA Manual Kit(200). The ForenSeqTMDNA Signature Prep Kit was used for library preparation, and next generation sequencing was performed on the MiSeq FGx system. The ForenSeqTMUniversal Analysis v1.2.1 software was used for data analysis. NGS-based STR results were compared with CE-based genotypes. Results A single length polymorphic STR allele in the mixed profile could be recognized as two sequence polymorphic STR alleles from different donors, which would assist mixed profile analysis. Such phenomenon was observed in D3S1358, D9S1122 and D13S317 in this work. Conclusion Our results suggested that precision STR genotyping of mixed samples based on NGS can provide more information and hints for mixed STR profile separation.

Large-scale signal detection: A unified perspective.

There is an overwhelmingly large literature and algorithms already available on "large-scale inference problems" based on different modeling techniques and cultures. Our primary goal in this article is not to add one more new methodology to the existing toolbox but instead (i) to clarify the mystery how these different simultaneous inference methods are connected, (ii) to provide an alternative more intuitive derivation of the formulas that leads to simpler expressions in order (iii) to develop a unified algorithm for practitioners. A detailed discussion on representation, estimation, inference, and model selection is given. Applications to a variety of real and simulated datasets show promise. We end with several future research directions.

A Color-Reaction-Based Biochip Detection Assay for RIF and INH Resistance of Clinical Mycobacterial Specimens.

The widespread occurrence of drug-resistant Mycobacterium tuberculosis places importance on the detection of TB (tuberculosis) drug susceptibility. Conventional drug susceptibility testing (DST) is a lengthy process. We developed a rapid enzymatic color-reaction-based biochip assay. The process included asymmetric multiplex PCR/templex PCR, biochip hybridization, and an enzymatic color reaction, with specific software for data operating. Templex PCR (tem- PCR) was applied to avoid interference between different primers in conventional multiplex- PCR. We applied this assay to 276 clinical specimens (including 27 sputum, 4 alveolar lavage fluid, 2 pleural effusion, and 243 culture isolate specimens; 40 of the 276 were non-tuberculosis mycobacteria specimens and 236 were M. tuberculosis specimens). The testing process took 4.5 h. A sensitivity of 50 copies per PCR was achieved, while the sensitivity was 500 copies per PCR when tem-PCR was used. Allele sequences could be detected in mixed samples at a proportion of 10%. Detection results showed a concordance rate of 97.46% (230/236) in rifampicin resistance detection (sensitivity 95.40%, specificity 98.66%) and 96.19% (227/236) in isoniazid (sensitivity 93.59%, specificity 97.47%) detection with those of DST assay. Concordance rates of testing results for sputum, alveolar lavage fluid, and pleural effusion specimens were 100%. The assay provides a potential choice for TB diagnosis and treatment.

Criterios de referencia para los indicadores de secreción de insulina y de los parámetros lipídicos en una población mixta hospitalaria / Reference criteria for insulin secretion indicators and of the lipid parameters in a hospital mixed population

INTRODUCCIÓN: la utilidad clínica de numerosos indicadores para el diagnóstico de la sensibilidad y la resistencia a la insulina es estudiada y aplicada frecuentemente con los mismos criterios de interpretación diagnóstica que fueron propuestos por sus autores. Las diferencias entre las características particulares de las distintas poblaciones y de la metodología empleada para la determinación de la glicemia y la insulinemia sobre el valor del punto de corte usado para el diagnóstico, requiere el uso de criterios diagnósticos representativos de esa población. Es difícil establecer criterios particulares porque la complejidad y el costo de la metodología directa convencional que usa poblaciones de referencia, es inaccesible en general a los laboratorios individuales. Existe una alternativa más simple, el método indirecto de estimación de rangos de referencia, basado en segregar poblaciones mixtas hospitalarias en sus componentes gausseanos, que pudiera ser el más adecuado para obtener criterios diagnósticos no sesgados. OBJETIVOS: calcular los límites de referencia de los principales indicadores para el diagnóstico de la resistencia a la insulina y la validez de los resultados obtenidos con este método. MÉTODOS: se estudiaron los parámetros estadísticos y los valores de referencia de 8 indicadores de secreción de la insulina, 3 indicadores de resistencia y 5 indicadores de sensibilidad a la insulina, derivados de la relación entre la glicemia y la insulinemia en ayunas, a partir de 1 000 muestras sucesivas de la población mixta hospitalaria que se atiende en el Instituto Nacional de Endocrinología. Se aplicó esta metodología a otros parámetros que también tienen una distribución asimétrica en la población, como la insulina y los lípidos séricos (colesterol y triglicéridos) y que cuentan con valores de referencia de aceptación universal, usados como control interno para evaluar si el método empleado brinda resultados no sesgados. Se aplicó el programa...(AU)

INTRODUCTION: the clinic usefulness of many indicators for the diagnosis of insulin-sensitivity and resistance is studied and frequently applied using the same criteria of diagnostic interpretation proposed by authors. The differences among the particular features of the different populations and the methodology used for determination of glycemia and the insulinemia over the cut point used for diagnosis require the use of diagnostic criteria representative of that population. It is difficult to establish particular criteria because of the complexity and the cost of the conventional direct methodology using reference populations is inaccessible in general to individual laboratories. There is a simpler alternative, the estimation indirect method of reference ranks, based on segregation of hospital mixed populations in its gaussean components that could be more appropriate to obtain non-biased diagnostic criteria. OBJECTIVE: to estimate the reference limits of main indicators for insulin-resistance and the validity of results obtained using this method. METHODS: authors studied the statistic parameters and reference values of 8 indicators of insulin secretion, 3 indicators of resistance and 5 indicators of insulin-sensitivity, derived from relation between fasting glycemia and insulinemia from 1 000 consecutive samples of hospital mixed population seen in National Institute of Endocrinology. We applied this methodology to other parameters with an asymmetric distribution in population; by example, insulin and serum lipids (cholesterol and triglycerides) having reference values of universal acceptation used as an internal control to assess if the method applied offers non-biased results. We applied the FAO program called Fish Stock Assessment Tools (FISAT) to separate the value of population in its...(AU)

Criterios de referencia para los indicadores de secreción de insulina y de los parámetros lipídicos en una población mixta hospitalaria / Reference criteria for insulin secretion indicators and of the lipid parameters in a hospital mixed population

INTRODUCCIÓN: la utilidad clínica de numerosos indicadores para el diagnóstico de la sensibilidad y la resistencia a la insulina es estudiada y aplicada frecuentemente con los mismos criterios de interpretación diagnóstica que fueron propuestos por sus autores. Las diferencias entre las características particulares de las distintas poblaciones y de la metodología empleada para la determinación de la glicemia y la insulinemia sobre el valor del punto de corte usado para el diagnóstico, requiere el uso de criterios diagnósticos representativos de esa población. Es difícil establecer criterios particulares porque la complejidad y el costo de la metodología directa convencional que usa poblaciones de referencia, es inaccesible en general a los laboratorios individuales. Existe una alternativa más simple, el método indirecto de estimación de rangos de referencia, basado en segregar poblaciones mixtas hospitalarias en sus componentes gausseanos, que pudiera ser el más adecuado para obtener criterios diagnósticos no sesgados. OBJETIVOS: calcular los límites de referencia de los principales indicadores para el diagnóstico de la resistencia a la insulina y la validez de los resultados obtenidos con este método. MÉTODOS: se estudiaron los parámetros estadísticos y los valores de referencia de 8 indicadores de secreción de la insulina, 3 indicadores de resistencia y 5 indicadores de sensibilidad a la insulina, derivados de la relación entre la glicemia y la insulinemia en ayunas, a partir de 1 000 muestras sucesivas de la población mixta hospitalaria que se atiende en el Instituto Nacional de Endocrinología. Se aplicó esta metodología a otros parámetros que también tienen una distribución asimétrica en la población, como la insulina y los lípidos séricos (colesterol y triglicéridos) y que cuentan con valores de referencia de aceptación universal, usados como control interno para evaluar si el método empleado brinda resultados no sesgados. Se aplicó el programa de la FAO, Fish Stock Assessment Tools (FISAT), para separar los valores de toda la población en sus componentes gausseanos y estimar los parámetros estadísticos del componente constituido por la población sana. Se compararon los resultados obtenidos por esta metodología con los valores de corte en uso en la institución. RESULTADOS: la metodología empleada permitió determinar los parámetros estadísticos del componente "normal" de la población mixta estudiada y proporcionó rangos de referencia para la glicemia (3,22-6,10 mmol/L), insulinemia (32-68 pmol/L), colesterol (2,2-5,28 mmol/L) y triglicéridos (0,65-1,97 mmol/L), similares a los aceptados generalmente, lo que se interpretó como un criterio de validez del método. Los resultados obtenidos en los indicadores de sensibilidad o resistencia a la insulina brindaron en general una sensibilidad diagnóstica mayor, con una menor especificidad. CONCLUSIONES: se concluyó que el uso de muestras mixtas hospitalarias y de la metodología descrita permite obtener, de una manera simple y confiable, rangos de referencia representativos de las condiciones locales(AU)

INTRODUCTION: the clinic usefulness of many indicators for the diagnosis of insulin-sensitivity and resistance is studied and frequently applied using the same criteria of diagnostic interpretation proposed by authors. The differences among the particular features of the different populations and the methodology used for determination of glycemia and the insulinemia over the cut point used for diagnosis require the use of diagnostic criteria representative of that population. It is difficult to establish particular criteria because of the complexity and the cost of the conventional direct methodology using reference populations is inaccessible in general to individual laboratories. There is a simpler alternative, the estimation indirect method of reference ranks, based on segregation of hospital mixed populations in its gaussean components that could be more appropriate to obtain non-biased diagnostic criteria. OBJECTIVE: to estimate the reference limits of main indicators for insulin-resistance and the validity of results obtained using this method. METHODS: authors studied the statistic parameters and reference values of 8 indicators of insulin secretion, 3 indicators of resistance and 5 indicators of insulin-sensitivity, derived from relation between fasting glycemia and insulinemia from 1 000 consecutive samples of hospital mixed population seen in National Institute of Endocrinology. We applied this methodology to other parameters with an asymmetric distribution in population; by example, insulin and serum lipids (cholesterol and triglycerides) having reference values of universal acceptation used as an internal control to assess if the method applied offers non-biased results. We applied the FAO program called Fish Stock Assessment Tools (FISAT) to separate the value of population in its Gaussean components and to estimate the statistic parameters of component created by health population. We compared the results obtained using this methodology with cut value used in by this institution. RESULTS: the methodology used allowed us to determine the statistic parameters or "normal" component of study mixed population and provides reference ranks for glycemia (3,22-6,10 mmol/L), insulinemia (32-68 pmol/L), cholesterol (2,2-5,28 mmol/L) and triglycerides (0,65-1,97 mmol/L) similar to those generally accepted considered as a criterion of method validity. Results obtained in the insulin sensitivity and resistance indicators gave us a greater diagnostic sensitivity with a lower specificity. CONCLUSIONS: we concluded that the use of hospital mixed samples and of methodology described allows obtaining in a reliable and simple way reference ranks representative of the local conditions(AU)