Biochar as a sustainable alternative to carbon black in agricultural mulch films.

Examples of biochar as an alternative to traditional plastic fillers, like carbon black, are numerous and growing. However, in the agricultural mulch film application, both the polymer and its fillers are pushed to their mechanical limit to obtain an effective product, using the least amount of plastic. Through a combined techno-economic analysis (TEA) and life cycle assessment (LCA), this study characterizes the use of carbon-negative biochar as an opacity filler in mulch film applications. Due to its larger particle size, the biochar demands additional thickness to achieve equivalent opacity as carbon black in films. A thicker film translates to additional polymer demand, and a significant increase in price and environmental impact. A comparable formulation for an equal price ($623 per mulched ha) as a 2.6 wt % carbon black with 25 µm thickness was derived, needing 15 wt % biochar and a thickness of 30 µm. The biochar formulation resulted in a slightly higher global warming potential (3% increase), but much larger impact in the land use category (+339%), and the sample was deemed not fit for use in the intended mulch application. These results indicate that in applications where the polymeric matrix and its fillers are pushed to their mechanical limit, the displacement of traditional fillers by biochar is challenging. However, biochar derived from waste biomass (thus reducing land use impact) remains a valid, environmentally beneficial solution to displace traditional fillers for non-extreme plastic uses (commodity plastics) and thicker composites.

Characterization and Comparative Analysis of Voids in Class II Composite Resin Restorations by Optical Coherence Tomography.

PURPOSE: This study aimed to characterize and analyze the number of voids and the percentage of void volume within and between the layers of class II composite restorations made using the bulk fill technique or the incremental technique by optical coherence tomography (OCT). METHODS AND MATERIALS: Class II cavities (4×4×2 mm) were prepared in 48 human third molars (n=24 restorations per group, two class II cavities per tooth). Teeth were divided into four groups and restored as follows: group 1 (FOB), bulk filled in a single increment using Filtek One Bulk Fill (3M Oral Care); group 2 (FXT), incrementally filled using four oblique layers of Filtek Z350 XT (3M Oral Care); group 3 (FBF+FXT), bulk filled in a single increment using Filtek Bulk Fill Flowable Restorative (3M Oral Care) covered with two oblique layers of Filtek Z350 XT (3M Oral Care), and group 4 (FF+FXT), incrementally filled using Filtek Z350 XT Flow (3M Oral Care) covered with two oblique layers of Filtek Z350 XT (3M Oral Care). After the restorative procedure, specimens were immersed into distilled water and stored in a hot-air oven at 37°C. Forty-eight hours later, thermal cycling was conducted (5000 cycles, 5°C to 55°C). Afterward, OCT was used to detect the existence of voids and to calculate the number of voids and percentage of voids volume within each restoration. Data were submitted to chi-square and Kruskal-Wallis tests (α=0.05). Comparisons were made using the Dunn method. RESULTS: Voids were detected in all groups, ranging from 0.000002 (FBF+FXT and FF+FXT) to 0.32 mm3 (FBF+FXT). FF + FXT presented voids in all of the restorations and had a significantly higher number of voids per restoration when compared to the other groups (p<0.05), but restorations with the presence of voids were significantly higher only when compared to FXT (p<0.05). FBF + FXT presented a significantly higher percentage of voids volume than that of FXT (p<0.05). When comparing restorations made using high-viscosity resin-based composites (FOB and FXT), no significant differences regarding number of voids or percentage of voids volume were detected (p≥0.05). CONCLUSIONS: The use of flowable resin-based composites can result in an increased number of voids and percentage of voids volume in restorations, and this appears to be more related to voids present inside the syringe of the material than to the use of incremental or bulk fill restorative techniques.

A biosensor capable of identifying low quantities of breast cancer cells by electrical impedance spectroscopy.

Breast cancer (BC) is a malignant disease with a high prevalence worldwide. The main cause of death is not the primary tumor, but instead the spread of tumor cells to distant sites. The aim of the present study was to examine a new method for the detection of cancer cells in aqueous medium using bioimpedance spectroscopy assisted with magnetic nanoparticles (MNP's) exposure to a constant magnetic field. The spectroscopic patterns were identified for three breast cancer cell lines. Each BC cell line represents a different pathologic stage: the early stage (MCF-7), invasive phase (MDA-MB-231) and metastasis (SK-BR-3). For this purpose, bioimpedance measurements were carried out at a certain frequency range with the aid of nanoprobes, consisting of magnetic nanoparticles (MNPs) coupled to a monoclonal antibody. The antibody was specific for the predominant cell surface protein for each cell line, which was identified by using RT-qPCR and flow cytometry. Accordingly, EpCAM corresponds to MCF-7, MUC-1 to MDA-MB-231, and HER-2 to SK-BR-3. Despite their low concentrations, BC cells could be detected by impedance spectroscopy. Hence, this methodology should permit the monitoring of circulating tumor cells (CTC) and therefore help to prevent recurrences and metastatic processes during BC treatment.

Electrical bioimpedance spectroscopy as biosensor technique to identify cells lineages and cell differentiation process.

The identification and characterization of diverse cells types and cell differentiation process requires complex techniques as flow cytometry, immunocytochemistry and the exploration of molecular markers; such techniques require infrastructure and qualified personnel. The objective of this study was to analyze the use of Electrical Bioimpedance Spectroscopy (EBIS) measurements as a non-complex alternative technique to identify populations of undifferentiated mouse Pluripotent Stem Cells (mPSCs), Mouse Embryonic Fibroblasts (MEFs) and the differentiation process from preadipocytes (3T3-L1) to mature adipocytes. EBIS measurements were compared in populations of cells which were characterized previously using microscopy. The results indicate that EBIS technique has a potential sensitivity at certain frequency range to discriminate between both evaluated cell populations and some differentiation process. Additional studies with different concentrations to evaluate quantitatively the sensitivity and specificity of the proposed technique are recommended.

Potential of resource recovery in UASB/trickling filter systems treating domestic sewage in developing countries.

This paper aims to present perspectives for energy (thermal and electric) and nutrient (N and S) recovery in domestic sewage treatment systems comprised of upflow anaerobic sludge blanket (UASB) reactors followed by sponge-bed trickling filters (SBTF) in developing countries. The resource recovery potential was characterized, taking into account 114 countries and a corresponding population of 968.9 million inhabitants living in the tropical world, which were grouped into three desired ranges in terms of cities' size. For each of these clusters, a technological arrangement flow-sheet was proposed, depending on their technical and economic viability from our best experience. Considering the population living in cities over 100, 000 inhabitants, the potential of energy and nutrient recovery via the sewage treatment scheme would be sufficient to generate electricity for approximately 3.2 million residents, as well as thermal energy for drying purposes that could result in a 24% volume reduction of sludge to be transported and disposed of in landfills. The results show that UASB/SBTF systems can play a very important role in the sanitation and environmental sector towards more sustainable sewage treatment plants.

Componentes Principales mediante Espectroscopia FTIR como Técnica de Caracterización Innovadora durante la Diferenciación de Células Madre Pluripotentes a Células Pancreáticas / Principal Components by FTIR Spectroscopy as Innovative Characterization Technique during Differentiation of Pluripotent Stem Cells to Pancreatic Cells

Resumen: Dos de los grandes retos en la biología de las Células Madre (CM) y la Medicina Regenerativa, son el control en la diferenciación de estas células y asegurar la pureza de las células diferenciadas, por lo que es necesario contar con técnicas rápidas, eficientes y precisas para la caracterización de CM y su diferenciación a diferentes linajes celulares. El objetivo de este trabajo fue analizar Células Madre Pluripotentes (CMP) y Células Pancreáticas Diferenciadas (CPD) mediante espectroscopía Infrarroja por Transformada de Fourier (FTIR) y Análisis de Componentes Principales (ACP). Para ello se diferenciaron CMP a CPD, caracterizando el proceso de diferenciación a los días 0, 11, 17 y 21 mediante microscopía óptica y espectroscopia vibracional. Los espectros FTIR se analizaron con el método multivariado de ACP, utilizando su segunda derivada en las regiones de proteínas, carbohidratos y ribosas. Los resultados indican que el ACP permite caracterizar y discriminar CMP y CPD en sus diferentes etapas de diferenciación en las regiones espectrales analizadas. Con lo anterior concluimos que el ACP permite caracterizar química y estructuralmente CMP y diferentes etapas de su diferenciación en una forma rápida, precisa y no invasiva.

Abstract: Two of the greatest challenges in Stem Cells (SCs) biology and regenerative medicine, are differentiation control of SCs and ensuring the purity of differentiated cells. In this sense, fast, efficient and accurate techniques for SCs characterization and their differentiation into different cell lineages are needed. The aim of this study was to analyse Pluripotent Stem Cells (PSCs) and Differentiated Pancreatic Cells (DPCs) by Fourier Transform Infrared (FTIR) spectroscopy and Principal Component Analysis (PCA). For this purpose, we differentiated PSCs toward DPCs, characterizing the differentiation process at different stages (0, 11, 17 and 21 days) through light microscopy and vibrational spectroscopy. FTIR spectra were analysed with the multivariate method of PCA, using the second derivatives in the protein, carbohydrate and ribose regions. The results indicate that the PCA allows to characterize and discriminate PSCs and DPCs at different stages of differentiation in the analysed spectral regions. From these results, we concluded that the PCA allows the chemically and structural characterization of PSCs and the different stages of their differentiation in a fast, accurate and non-invasive way.

Evaluación de Termografía Tisular Diferenciada en Mama como Potencial Técnica para Asistir la Detección de Cáncer / Evaluation of Thermography Differentiated in Breast Tissue as Potential Technique to Assist Cancer Detection

Diversos grupos han propuesto el procesamiento de imágenes termográficas para detección de Cáncer de Mama (CaMa). Angiogénesis y vascularización dependientes del ciclo menstrual, edad e Índice de Masa Corporal (IMC) modifican la temperatura absoluta en la superficie tisular sin estar necesariamente asociadas a malignidad, en éste estudio proponemos la Termografía Tisular Diferenciada (TTD) en mama con respecto a su contralateral en espejo con el fin de observar diferencias térmicas características de malignidad. El presente trabajo evalúa la posibilidad de emplear la TTD como potencial técnica para asistir la detección de CaMa. Se muestrearon 110 mujeres voluntarias entre 40 y 60 años de edad segmentadas en dos grupos experimentales: grupo sanas (n=90) y grupo con CaMa (n=20) previamente diagnosticadas por mastografía e histopatología. Imágenes termográficas de ambas mamas fueron adquiridas con una cámara infrarroja y se estimó la TTD en relación a la mama contralateral de la misma paciente, se realizó un análisis de sensibilidad y especificidad y se comparó con el diagnóstico radiológico a través de curvas ROC tomando como referencia el diagnóstico histopatológico. La TTD en mama mostró rangos dinámicos diferenciables entre condiciones de malignidad respecto a benignidad. El análisis ROC mostró valores de sensibilidad y especificidad para el estimado TTD del 70% y 54% mientras que para el diagnóstico radiológico fue del 70% y 96%, respectivamente. La TTD muestra viabilidad técnica para asistir la detección de CaMa.

Several groups have proposed thermographic image processing for Breast Cancer (BC) detection. Angiogenesis and vascularization of menstrual cycle dependent, as well as age and Body Mass Index change the absolute temperature in the tissue surface without necessarily being associated with malignancy. We have proposed the Differentiated Tissue Thermography (DTT) in breast regarding its contralateral mirror in order to observe differences in temperature characteristics of malignancy. This study evaluates the possibility of using breast DTT as a potential technique to assist the detection of BC. We sampled 110 female volunteers between 40 and 60 years old segmented into two experimental groups: healthy group (n=90) and BC group (n=20), which were diagnosed by mammography and histopathology. Thermal images of both breasts were acquired with an infrared camera and the DTT was estimated relative to its contralateral breast in the same patient. A sensitivity and specificity analysis was developed and the DTT was compared with the radiological diagnosis by ROC curves with the histopathological report as reference. The DTT values showed distinguishable dynamic ranges between malignant and healthy conditions. ROC analysis showed sensitivity and specificity values for DTT of 70% and 54% while for the radiological diagnosis was 70% and 96% respectively. DTT showed technical viability to assist BC detection.

Effect of inter-breed embryo transfer on lamb growing performance and survival.

The roles of recipient and embryo genotype in determining the growth performance and survivability of offspring based on specific behavioural differences were investigated using inter-breed embryo transfer. This study was carried out using three recipient genotypes (Awassi, Redkaraman and Tuj) and two embryo genotypes (Charollais and Romanov) to obtain the six possible combinations of ewe and lamb genotypes. Data were collected from 71 recipient ewes (10 Redkaraman with Charollais and 15 Redkaraman with Romanov embryos; 10 Tuj with Charollais and 12 Tuj with Romanov embryos, and 12 Awassi with Charollais lambs and 12 Awassi with Romanov embryos); all ewes received two frozen-thawed embryos. Awassi ewes had a significantly longer duration of the licking/grooming event (25.5 min, p < 0.05) than Tuj ewes. Charollais lambs were significantly (p < 0.05) more likely to require birth assistance compared to Romanov lambs. Romanov lambs were significantly more (p < 0.01) active than Charollais lambs in the first 2 h after birth; ewe breed had no effect on lamb behaviour. There was no recipient breed effect on either birth or weaning weights of lambs. Charollais lambs were recorded with higher birth (5.5 ± 0.3 kg vs 3.9 ± 0.2 kg; p < 0.001) and weaning (29.4 ± 1.2 kg vs 22.4 ± 1.9 kg; p < 0.001) weights compared to Romanov lambs. At weaning Romanov lambs had significantly higher (95% vs 75%; p < 0.05) survival rates, however, this was not significantly affected by recipient breed. It was concluded that recipient breed was not an important factor in survival and weaning performance of embryo transferred lambs from a prolific breed (Romanov) while these traits recorded for lambs from meat type (Charollais) embryos were influenced by dam breed.

[Microbiological profile of infections in the Intensive Care Units of Colombia (EPISEPSIS Colombia]. / Perfil microbiológico de la Infecciones en Unidades de Cuidados Intensivos de Colombia (EPISEPSIS Colombia).

BACKGROUND AND OBJECTIVE: Valid and reliable data regarding sepsis is lacking in Colombia. Our aim was to determine the prevalence of the microorganisms in the main infections treated in Intensive Care Units (ICUs) in our country. METHODS: This is a sub-study of a prospective cohort with 10 general hospitals in Colombia during a 6-month period. The inclusion criteria were hospitalization in ICU and confirmation of infection according to the CDC definitions. Patients were classified into three groups, that is, community, hospital and intensive care, according to the site where the infection was acquired. RESULTS: A total of 826 patients were included in this analysis. Of these, 51% developed infections in the community, 5.33% in the hospital and 43.7% in intensive care unit. Overall, the most common diagnoses were pneumonia (29.54%), intra-abdominal infection (18.16%) and urinary tract infection (11.62%). The most frequent germ in community-acquired infections was E. coli -lung (16. 4%), peritoneum (57.7%), urine (55.5%), blood (22.4%)-. E. coli -peritoneum (29.3%), urine (52.9%)- also predominated in the ICU-acquired infections, except for lung and blood in which Staphylococcus aureus (32.4%) and Klebsiella pneumoniae (15.7%) were the most prevalent. Cultures were requested from 655 patients, 40% of them having received antibiotics before cultures were taken, although this did not affected the percentages of positive cultures (P=0.583). CONCLUSIONS: Pneumonia was the main cause of infection regardless of the site of acquisition. E. coli was the most prevalent germ, except in the pulmonary infections acquired in UCI in which S. aureus was the most prevalent.

Epididymal stereocilia in semen of infertile men: evidence of chronic epididymitis?

As free stereocilia in semen samples from infertile men could be related to a subclinical chronic infection of the seminal tract, we carried out a retrospective analysis of 14 files of infertile men with stereocilia in semen (group 1) and in two control groups: 30 infertile men from the same study population (group 2) and 40 fertile sperm donors (group 3). Clinical, bacteriological, sonographic and microscopic findings associated with these semen samples were compared. Epididymal cysts were found in two of 14 men in group 1 and in four of 28 in group 2. Positive semen cultures for Chlamydia trachomatis, Mycoplasma hominis or Ureaplasma urealyticum (chi(2) = 8.20; P = 0.002; OR: 7.22) and varicocele (chi(2) = 8.96; P = 0.002; OR: 2.25) were associated to the presence of free stereocilia in semen. These data suggest that a silent chronic infection of the epididymis by C. trachomatis, M. hominis, U. urealyticum and/or inflammation produced by varicocele might be the cause of stereocilia loss in the semen.

Prevalence of denervation in paraspinal and foot intrinsic musculature.

OBJECTIVE: The primary purpose of this investigation was to determine the prevalence of abnormal spontaneous activity (positive sharp waves (PSWs) and fibrillation potentials (FPs)) in selected lumbosacral paraspinal and foot intrinsic muscles in an asymptomatic healthy population. DESIGN: This was a prospective assessment of 50 individuals without history or physical findings suggestive of peripheral neuromuscular disease whereby a monopolar needle electrode was located in the unilateral L4 and L5 paraspinal as well as abductor hallucis and extensor digitorum brevis muscles. These muscles were extensively evaluated for the presence of PSWs, FPs, and fasciculation potentials. RESULTS: Ten subjects per decade from 20-59 yr and ten subjects from 60-80 yr comprised the 50 participants (28 women), resulting in a mean age of 45+/-15.9 (range, 20-76) yr. A single individual (prevalence, 2%) demonstrated fibrillation potentials in the extensor digitorum brevis, and FPs and PSWs were detected in two subjects' (4% prevalence) L4/L5 paraspinal muscles. Ninety-four percent of the subjects had fasciculation potentials in the abductor hallucis, whereas 60% had these waveforms in the extensor digitorum brevis. Only 6% of subjects had fasciculation potentials in the L4 but not L5 paraspinal muscles. All subjects demonstrated both prototypical and "atypical" appearing endplate spikes in all of the muscles examined. CONCLUSIONS: We failed to confirm the previously reported prevalence of FPs and PSWs in both the paraspinal and foot intrinsic musculature. Atypical appearing endplate spikes, however, display configurations similar to FPs and PSWs and were present in all subjects. Failure to pay close attention to the discharge rate and rhythm of endplate spikes can lead to misinterpreting these waveforms as FPs and PSWs. It is likely that the previously reported high prevalence of spontaneous activity in healthy persons resulted from not fully appreciating the similarity between innervated and denervated spontaneous single muscle fiber discharge configurations.

Rapid determination of PAHs in soil samples by HPLC with fluorimetric detection following sonication extraction.

A rapid method for the determination of PAHs in soil samples based on their extraction with methylene chloride by sonication and subsequent separation by HPLC with fluorimetric detection is proposed. A Hypersil Green PAH column was used with a gradient of acetonitrile/water as the mobile phase, together with a program of nine excitation and emission wavelength pairs. Recoveries were in the range 70-98%, except for acenaphthene and naphthalene, at concentration levels 1.08-442 microg/kg with relative standard deviations in the range 2-15% (n = 4). Total PAHs found in soil samples were in the range 15-282 microg/kg. The results were compared with those obtained by applying the 3540 EPA method for two samples.

Sperm dysfunction in subfertile patients with varicocele and marginal semen analysis.

A comparative analysis of potentially functional spermatozoa per ejaculate, progressive motility, hypo-osmotic swelling test, acrosome integrity and sperm viability (24 and 48 h) was carried out in a group of 40 subfertile patients with varicocele and marginal semen analysis and 40 fertile subjects, in order to identify subclinical abnormalities that may explain subfertility. Patients with varicocele had lower numbers of potentially functional spermatozoa per ejaculate, progressive motility, acrosome and membrane integrity and sperm viability. These abnormalities were not related to the grade of varicocele, testicular volume or serum FSH concentration. A positive correlation between the hypo-osmotic swelling test and progressive motility (r = 0.71) and between potentially functional spermatozoa and the hypo-osmotic swelling test (r = 0.69) was found in patients with varicocele. These data suggest that some of the deleterious effects produced by the varicocele might be related to sperm migration and viability in the female genital tract and others to sperm-zona interaction and/or sperm-egg fusion.

Bacteriospermia and male infertility: a method for increasing the sensitivity of semen culture.

OBJECTIVE: To test a method for increasing the sensitivity of semen culture. Design-Prospective and transverse. Setting-Andrology clinic at a tertiary care health institution in Mexico City. PATIENTS: 65 infertile patients with abnormal semen, bacteriospermia detected on Gram stain and at least two previous negative semen cultures (<3 months) were included to test routine semen culture and a method including centrifugation of semen at 10,00 rpm for 20 minutes. Localization cultures were also carried out in all patients. MAIN OUTCOME MEASURE: Bacterial isolation in semen samples. RESULTS: Routine semen culture was positive in 22% of patients, while centrifuged aliquots of the same semen sample were positive in 52% of patients (chi2 = 6.60, P < .01). Enterococcus was isolated in 43% of patients, E. coli in 24%, coagulase-negative Staphylococcus in 19%, and U. urealyticum in 14%. Ninety percent of isolates corresponded to specimens from the urethra and the prostato-vesicular region. CONCLUSION: Sensitivity of semen culture increased with centrifugation of semen samples. Localization pattern and type of isolates suggest that these patients had chronic prostatitis and that episodic elimination of bacteria might also explain false negative semen cultures in patients with chronic asymptomatic infection of the accessory sex glands.

Molecular characterization of the fragile-X syndrome in the Mexican population.

The fragile X (fra-X) syndrome is the most frequent form of inherited mental retardation. Facial dysmorphism, macroorchidism and a folate-sensitive fragile site on Xq27.3 are commonly associated features. The gene causing this disorder, designated as FMR1, is X-linked and shows an unusual inheritance mode. A multistep amplification of the CGG repeats at the 5' end of the FMR1 gene has been recently identified as the cause of the fra-X syndrome. Different numbers of repeats define three gene forms (normal, premutated and mutated), whose ranges show little variation in the populations studied so far. We analyzed 18 Mexican individuals with the fra-X syndrome, 40 of their relatives (first and second degree), and 76 healthy individuals without antecedents of mental retardation. Southern blot and PCR permitted the assessment of the number of CGG repeats and the methylation state of the FMR1 gene for the normal, premutated, and mutated alleles. The results showed no statistical differences when compared with those from other populations. No cytogenetic expression of the Xq27.3 fragile site in 50% of the affected males and in all the affected and carrier females was observed. This finding emphasizes the necessity of a molecular analysis in fra-X cases and their relatives in order to provide a more adequate genetic counseling.

[The clinical study of male infertility]. / Estudio clínico de la infertilidad masculina.

Male infertility study requires systematization of clinical and paraclinical diagnostic procedures and the knowledge of frontier techniques to analyze functional capacity of human spermatozoon. The application of the various methods of assisted reproduction in male infertility treatment, should be judged with a good criterion in order to offer maximal benefit and least risk. New methods to handle gametes and standardization of existing ones, could, in the future, offer better alternatives in male infertility treatment.

Uso práctico de los índices de trauma / Trauma indexes: a practical use

Presentamos una propuesta para la aplicación práctica de metodos de cuantificacion del trauma, en el Hospital San Juan de Dios de Santa Fe de Bogota. Al ingreso del paciente al servicio de Urgencias se calcula un indice fisiologico, el Revised Trauma Score (RTS). En el postoperatorio se realiza el Injury Severity Score (ISS), con base en el Abbreviated Injury Scale (AIS), que indica la severidad anatómica de la lesion. Con los anteriores datos y la edad, se calcula el Trauma Score-Injury Severity Score (TRISS), con lo que se obtiene la Probabilidad de supervivencia (Ps). Para el paciente con trauma abdominal, se calcula el Abdominal Trauma Index (ATI), como indice pronostico de complicaciones , utilizando el Organ Injury Scaling (OIS). Al paciente con trauma torácico se le cuantifica el Penetrating Thoracic Trauma Index (PTTI), con el cual se obtiene como resultado, al sumarlo con el ATI, el Penetrating Trauma Index (PTI). Con estos indices se pretende cuantificar la severidad del trauma y lograr una buena prediccion de los resultados, lo que permite evaluar la calidad de la atencion, comparar grupos e inclusive guiar politicas administrativas.

[Index of cells obtainable from semen: indicator of fertility?]. / Indice de células recuperables del semen: indicador de fertilidad?

It has been recognized that semen analysis is not a sensible nor a specific tool for detecting infertility in the male. Its predictive value is limited by the subjectivity of manual analysis, a high variability of semen parameters in fertile men and lack of correlation between sperm characteristics and fertility indexes. In this paper we present evidence supporting the concept that calculating an index of potentially fertile cells from data obtained in a regular semen analysis might be useful for predicting fertility in the male.