Photoluminescent lateral flow based on non-radiative energy transfer for protein detection in human serum

A new paper-based lateral flow immunoassay configuration was engineered and investigated. The assay is intended for the detection of a model protein in human serum, that is, human immunoglobulin G, with the aim to demonstrate a virtually universal protein detection platform. Once the sample is added in the strip, the analyte is selectively captured by antibody-decorated silica beads (Ab-SiO) onto the conjugate pad and the sample flows by capillarity throughout the strip until reaching the test line, where a sandwich-like immunocomplex takes place due to the presence of antibody-functionalized QDs (Ab-QDs) onto the test line. Eventually, GO is added as a revealing agent and the photoluminescence of those sites protected by the complex Ab-SiO/Antigen/Ab-QDs will not be quenched, whereas those photoluminescent sites directly exposed are expected to be quenched by GO, including the control line, made of bare QDs, reporting that the assay occurred successfully. Hence, the photoluminescence of the test line is modulated by the formation of sandwich-like immunocomplexes. The proposed device achieves a limit of detection (LOD) of 1.35 ng mL in standard buffer, which is lower when compared with conventional lateral flow technology reported by gold nanoparticles, including other amplification strategies. Moreover, the resulting device was proven useful in human serum analysis, achieving a LOD of 6.30 ng mL in this complex matrix. This low-cost disposable and easy-to-use device will prove valuable for portable and automated diagnostics applications, and can be easily transferred to other analytes such as clinically relevant protein biomarkers

Prevalence and factors associated with a higher risk of neck and back pain among permanent wheelchair users: a cross-sectional study

[EN] Study design: Cross-sectional study. Objectives: To determine the prevalence of, and factors associated with, spinal pain among wheelchair users. Setting: Four Spanish hospitals specialized in providing care for wheelchair users. Methods: Persons who had used a wheelchair for a median (IRQ) of 10 (5;19) years, 27% of them due to reasons other than spinal cord injury, were recruited consecutively (n = 750). Data on 43 demographic, psychosocial, ergonomic, and clinical variables were collected, and analyzed. Main outcome measures were: Point prevalence of neck (NP), thoracic (TP), low back pain (LBP), and pain at any spinal level (PASL); and factors associated with them. Results: Point prevalence was 56% for NP, 54% for TP, 45% for LBP, and 76% for PSAL. PASL was associated with a lower quality of life (OR (95% CI) 0.91 (0.86; 0.97)). Multivariable regression models showed that the main factors associated with significant pain (≥1.5 VAS points) were: (a) For NP: Cervical spinal injury and wheelchair seat cushion thickness, (b) For TP: Thoracic spinal injury and sagittal index, (c) For LBP: Thoracic or lumbar spinal injury, with some sensitivity remaining, (d) For PASL: Being female, living alone, and using a non-power wheelchair. Discrimination (AUC) of these models ranged between 0.638 and 0.818. p-values in the Hosmer-Lemeshow test ranged between 0.420 and 0.701. Conclusions: Prevalence of spinal pain among wheelchair users is high. It is associated with a lower quality of life. Future studies should assess whether using a power wheelchair affects PASL, and if the thickness of seat cushion affects NP. Sponsorship: Spanish Back Pain Research NetworkS

Magnetic and structural characterization of mechanically alloyed Fe_50-Co_50 samples

Samples of nominal composition Fe50Co50 were produced by mechanical alloying by using a planetary ball mill and different milling times. The samples were studied via X-ray diffraction, Mössbauer spectroscopy, and X-ray photoelectron spectroscopy to characterize the phase distribution resulting from the milling process. The Mössbauer data indicated that Co starts diffusing into Fe after 8 h of milling. Between t = 8h and t = 24 h the sample has a heterogeneous composition, presenting a bimodal hyperfine field distribution with maxima centred at 34.3 T and 35.8 - 36.4 T, compatible with the presence of different Fe environments (richer in Co and richer in Fe, respectively). After 48 h of milling, the sample presents a more homogeneous composition showing an almost symmetric hyperfine magnetic field distribution centred at H=34.9 T, indicating that a disordered equiatomic FeCo solid solution has already been formed. The X-ray photoelectron spectroscopy data indicate that the native oxide layer formed on the freshly milled samples contains Co2+, Fe2+ and Fe3+ oxides. After complete removal of this native oxide layer by Ar ion bombardment, X-ray photoelectron spectroscopy analysis yields the composition of the nominal equiatomic Fe50Co50 alloy

Magnetic and Structural Characterization of Mechanically Alloyed Fe50co50 Samples

Samples of nominal composition Fe50Co50 were produced by mechanical alloying byusing a planetary ball mill and different milling times. The samples were studied via X-raydiffraction, Mössbauer spectroscopy, and X-ray photoelectron spectroscopy to characterize thephase distribution resulting from the milling process. The Mössbauer data indicated that Co startsdiffusing into Fe after 8 h of milling. Between t = 8h and t = 24 h the sample has a heterogeneouscomposition, presenting a bimodal hyperfine field distribution with maxima centred at 34.3 T and35.8 - 36.4 T, compatible with the presence of different Fe environments (richer in Co and richerin Fe, respectively). After 48 h of milling, the sample presents a more homogeneous compositionshowing an almost symmetric hyperfine magnetic field distribution centred at H=34.9 T,indicating that a disordered equiatomic FeCo solid solution has already been formed. The X-rayphotoelectron spectroscopy data indicate that the native oxide layer formed on the freshly milledsamples contains Co2+, Fe2+ and Fe3+ oxides. After complete removal of this native oxide layer byAr ion bombardment, X-ray photoelectron spectroscopy analysis yields the composition of thenominal equiatomic Fe50Co50 alloy

Physician-Related Variability in the Outcomes of an Invasive Treatment for Neck and Back Pain: A Multi-Level Analysis of Data Gathered in Routine Clinical Practice

[EN] Neuro-reflexotherapy (NRT) is a proven effective, invasive treatment for neck and back pain. To assess physician-related variability in results, data from post-implementation surveillance of 9023 patients treated within the Spanish National Health Service by 12 physicians were analyzed. Separate multi-level logistic regression models were developed for spinal pain (SP), referred pain (RP), and disability. The models included all patient-related variables predicting response to NRT and physician-related variables. The Intraclass Correlation Coefficient (ICC) and the Median Odds Ratio (MOR) were calculated. Adjusted MOR (95% CI) was 1.70 (1.47; 2.09) for SP, 1.60 (1.38; 1.99) for RP, and 1.65 (1.42; 2.03) for disability. Adjusted ICC (95%CI) values were 0.08 (0.05; 0.15) for SP, 0.07 (0.03; 0.14) for RP, and 0.08 (0.04; 0.14) for disability. In the sensitivity analysis, in which the 6920 patients treated during the physicians’ training period were excluded, adjusted MOR was 1.38 (1.17; 1.98) for SP, 1.37 (1.12; 2.31) for RP, and 1.25 (1.09; 1.79) for disability, while ICCs were 0.03 (0.01; 0.14) for SP, 0.03 (0.00; 0.19) for RP, and 0.02 (0.00; 0.10) for disability. In conclusion, the variability in results obtained by different NRT-certified specialists is reasonable. This suggests that current training standards are appropriateS

Predicting the evolution of neck pain episodes in routine clinical practice

[EN] Background: The objective of this study was to develop models for predicting the evolution of a neck pain (NP) episode. Methods: Three thousand two hundred twenty-five acute and chronic patients seeking care for NP, were recruited consecutively in 47 health care centers. Data on 37 variables were gathered, including gender, age, employment status, duration of pain, intensity of NP and pain referred down to the arm (AP), disability, history of neck surgery, diagnostic procedures undertaken, imaging findings, clinical diagnosis, and treatments used. Three separate multivariable logistic regression models were developed for predicting a clinically relevant improvement in NP, AP and disability at 3 months. Results: Three thousand one (93.5%%) patients attended follow-up. For all the models calibration was good. The area under the ROC curve was ≥0.717 for pain and 0.664 for disability. Factors associated with a better prognosis were: a) For all the outcomes: pain being acute (vs. chronic) and having received neuro-reflexotherapy. b) For NP: nonspecific pain (vs. pain caused by disc herniation or spinal stenosis), no signs of disc degeneration on imaging, staying at work, and being female. c) For AP: nonspecific NP and no signs of disc degeneration on imaging. d) For disability: staying at work and no signs of facet joint degeneration on imaging. Conclusions: A prospective registry can be used for developing valid predictive models to quantify the odds that a given patient with NP will experience a clinically relevant improvementSIThis study was funded by the Spanish Back Pain Research Network (REIDE), a Spanish not-for-profit organization which specializes in neck and back pain research. REIDE is funded by: a) The Kovacs Back pain Unit in the Hospital Universitario HLA-Moncloa, a private organization specializing in neck and back pain, dedicated to medical research, health care and promotion of public health, with no links to the health industry b) Fundación ASISA, a Spanish non-profit institution linked to a health insurance company (ASISA) owned by a physician’s cooperativ

PREVALENCIA DE ENTEROBACTERIAS RESISTENTES EN INFECCIONES URINARIAS DE MUJERES GESTANTES EN EL HOSPITAL SANTAMARIA DE LA CIUDAD DE CUTERVO 2014 – 2015

La presente investigación de corte epidemiológica - descriptiva practicada en la Ciudad de Cutervo – Cajamarca; presentó una muestra acumulativa de  224  mujeres gestantes con  infección urinaria, a las cuales se les practicó análisis clínico a la muestra urinaria; con la finalidad de determinar la prevalencia de Enterobacterias resistentes a infecciones urinarias de mujeres comprendidas  entre  14  y 45 años  de  edad   atendidas en  el    Hospital  “Santa  María”   Cutervo -  Cajamarca.  Para  el  descarte  de  Infecciones del Tracto Urinario (ITU)  se consideró   en  primer  lugar el cuadro clínico  y luego  el análisis de orina, donde  se confirmó con el sedimento urinario y el urocultivo,atraves de un antibiograma. La interpretación de la sensibilidad y resistencia in vitro se hizo en base al tamaño de la zona de inhibición según los parámetros establecidos en la técnica de Kirby-Bauer. De  las  224  muestras  examinadas ,  se  reportaron   35 casos(15.62%)  de  resistencia y  189 casos(84.38%)   fueron  sensibles a  los antibióticos, donde la  entero bacteria  más  frecuente  fue  E.coli (100%). De  las  35 (100%)  muestras positivas  para  enterobacterias   se encontró  10(28.6%) muestras resistente. Se demostró que los  antibiótico  frente  al cual  se  encontró  mayor resistencia  fue  la  Gentamicina 35(100%),  seguido  de  la  Amoxicilina 7(20%), Trimetropina  + Sulfametoxasol 6(17.14%) y  la Nitrofurantoina 3(8.57%

Human pregnane X receptor is expressed in breast carcinomas, potential heterodimers formation between hPXR and RXR-alpha.

The human pregnane X receptor (hPXR) is an orphan nuclear receptor that induces transcription of response elements present in steroid-inducible cytochrome P 450 gene promoters. This activation requires the participation of retinoid X receptors (RXRs), needed partners of hPXR to form heterodimers. We have investigated the expression of hPXR and RXRs in normal, premalignant, and malignant breast tissues, in order to det. whether their expression profile in localized infiltrative breast cancer is assocd. with an increased risk of recurrent disease. Methods: Breast samples from 99 patients including benign breast diseases, in situ and infiltrative carcinomas were processed for immunohistochem. and Western-blot anal. Results: Cancer cells from patients that developed recurrent disease showed a high cytoplasmic location of both hPXR isoforms. Only the infiltrative carcinomas that relapsed before 48 mo showed nuclear location of hPXR isoform 2. This location was assocd. with the nuclear immunoexpression of RXR-alpha. Conclusion: Breast cancer cells can express both variants 1 and 2 of hPXR. Infiltrative carcinomas that recurred showed a nuclear location of both hPXR and RXR-alpha; therefore, the overexpression and the subcellular location changes of hPXR could be considered as a potential new prognostic indicator

Variación morfológica y reproductiva de nueve poblaciones naturales de Lupinus campestris Cham. & Schltdl. de la región centro oriente de Puebla, México

El género Lupinus L. (Fabaceae) es de alta calidad nutrimental por su alto porcentaje de proteína en semillas y follaje; útil para la restauración ecológica de suelos degradados por su capacidad para fijar nitrógeno. Para el estudio de diversidad genética existen marcadores; morfológicos y moleculares. El proceso de domesticación y obtención de variedades se basa en la caracterización morfológica del fenotipo, al estudiar la variabilidad morfológica entre diversas poblaciones naturales. El objetivo fue determinar la variación fenotípica, parámetros reproductivos y capacidad de fijación de nitrógeno a través de la reducción de acetileno de nueve poblaciones de L. campestris procedentes en un intervalo altitudinal del centro-oriente de Puebla, México. Se recolectó germoplasma, el cual se propagó en condiciones de invernadero. En la mayoría de las características evaluadas hubo diferencias significativas (p>0.001). La población de Atzitzintla produjo el número mayor de vainas (479), así como en peso total de semillas (22 g). La capacidad de fijación de N2 resultó mayor entre las plántulas procedentes de Tlalmotolo. Se observó variación significativa en las características morfológicas de las plantas y en el potencial reproductivo. En las semillas la variabilidad fue significativa entre y dentro de poblaciones