A feasible approach to measure metal concentrations in drill hole waters on site for mineral exploration

The new technologies used in the green transition towards carbon-free societies typically demand extensive use of metals. This leads to a heavily growing need for exploration and extraction of ore deposits. Exploration can be facilitated by measuring metal concentrations in ground and surface waters carrying trace concentrations of metals leached from nearby deposits. Currently, measuring metal concentrations in water is slow and expensive and it cannot be done on-site, which hinders the discovery of new ore deposits. To address this challenge, we have developed a method to collect and concentrate the dissolved metals in a solid filter and measure the metal concentrations directly from the filter with a portable X-ray fluorescence spectrometer. The permeable filter is made of mesoporous silicon modified with bisphosphonates. Two types of adsorbing materials for the filters were prepared based on scalable production methods: i) regenerative etching of metallurgical grade silicon powder, and ii) magnesiothermic reduction of silica from barley husks. Empirical calibrations were prepared in a concentration range of 10-200 μg/L for Mn, Co, Ni, Cu, Zn, and Pb using water samples prepared by spiking well water with standard metal solutions. Both filter types were tested for their ability to adsorb metals from the real water samples taken from drill holes. The developed system was able to detect metal concentrations down to 12 μg/L (ppb) showing its potential for on-site measurements of dissolved metals in water samples, which could be feasible in the discovery of new mineral deposits. This innovation enables smart sampling during exploration and provides real-time information on metal concentrations in water.

Comparison of neuromuscular fatigability amplitude and etiologies between fatigued and non-fatigued cancer patients

PURPOSE

Cancer-related fatigue (CRF) is the most reported side effect of cancer and its treatments. Mechanisms of CRF are multidimensional, including neuromuscular alterations leading to decreased muscle strength and endurance (i.e., fatigability). Recently, exercise fatigability and CRF have been related, while fatigability mechanisms remain unclear. Traditionally, fatigability is assessed from maximal voluntary contractions (MVC) decrease, but some authors hypothesized that the rate of force development (RFD) determined during a rapid contraction could also be an interesting indicator of functional alterations. However, to our knowledge, no study investigated RFD in cancer patients. The purpose of this study was to determine whether RFD, fatigability amplitude, and etiology are different between fatigued and non-fatigued cancer patients.

METHODS

Eighteen participants with cancer, divided in fatigued or non-fatigued groups according their CRF level, completed a 5-min all-out exercise in ankle plantar flexor muscles composed of 62 isometric MVC of 4 s with 1 s rest, to assess fatigability amplitude as the force-time relationship asymptote (FA). Before and after exercise, fatigability etiologies (i.e., voluntary activation (VA) and evoked forces by electrical stimulation (Db100)) were assessed as well as RFD in 50 and 100 ms (RFD50 and RFD100, respectively) during rapid contractions.

RESULTS

FA is significantly lower in fatigued group. Significant differences were found between pre- and post-exercise VA, Db100, RFD50, and RFD100 for both groups, with no statistical difference between groups.

CONCLUSION

During treatments, fatigability is higher in fatigued patients; however, the mechanisms of fatigability and RFD alterations are similar in both groups.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04391543, May 2020.

Potential of Marine Strains of Pseudoalteromonas to Improve Resistance of Juvenile Sea Bass to Pathogens and Limit Biofilm Development

The European sea bass (Dicentrarchus labrax), one of the most produced marine fish species in Europe, is acutely vulnerable to multiple infectious hazards. In this study, we investigated the potential probiotic effect of some marine Pseudoalteromonas bacterial strains against two major pathogens of this species, Vibrio harveyi and the nervous necrosis virus (NNV), and examined their antibiofilm effect. Impregnation phase was done by repeated immersion of juvenile's sea bass during 8 to 12 weeks in seawater containing the probiotic candidates at a concentration of 106 CFU/mL. Four candidates were tested: (1) a combination of two strains producing antimicrobial compounds, hCg-42 and hOe-125; (2) strain 3J6, with known antibiofilm properties; (3) strain RA15, from the same genus, but with no identified probiotic effect; and (4) a control group without probiotics. At the end of the impregnation phase, fish underwent an infection challenge with V. harveyi or with a pathogenic strain of NNV and mortality was monitored. For the V. harveyi challenge, improved survival rates of 10 and 25% were obtained for the RA15 and the mix hCg-42 + hOe-125-impregnated groups, respectively. For the NNV challenge, no significant benefic effect of the probiotics on infection kinetics or cumulative mortality was observed. At the end of the impregnation phase, the maximal thickness of biofilm was significantly lower in the 3J6, double strain, and RA15 groups, compared with the non-impregnated control group. This study highlights the interesting probiotic potential of marine bacteria to limit mortalities induced by bacterial pathogens as well as biofilm development.

Delayed cervical cancer diagnosis: a systematic review

OBJECTIVE

Cervical cancer (CC) is a preventable women's cancer. Vaccination and routine Pap smear screening have reduced cervical cancer-related mortality by 70-80% in the world. The eradication of CC depends on identifying the disease early and removing barriers to its timely detection. This review study was designed to determine diagnostic delay and factors related to delayed CC diagnosis in the world.

MATERIALS AND METHODS

A comprehensive search was carried out in databases including Medline, Web of Science, Core Collection (Indexes = SCI-EXPANDED, SSCI, A & HCI Timespan), and Scopus for articles published up to December 2021. Publications were included if they reported data on the delayed CC, and factors related to diagnosis of CC in women. There was no time restriction in this review.

RESULTS

In total, 45 articles were entered into the study. In studies, advanced stages of CC (IIB to IV) varied from 10.2% to 87.9% due to delayed diagnosis. A delayed CC diagnosis was reported in 4.3%-89.1% of patients. The median and mean days of delayed diagnosis were 59-210 days and 2.92-10.5 months, respectively. Factors related to delayed CC diagnosis were categorized into three components including patient, medical history, and health system delay. Patient delay included socio-demographic, husband/ partner, and knowledge. Medical history included medical issues, obstetrics, and family history. Health system delays included health facilities and levels of accessibility.

CONCLUSIONS

There is an urgent need to shorten the diagnostic journey of CC patients by addressing all the components of diagnostic delay and developing strategies to modify the factors associated with these delays.

Microfluidic synthesis of retinoic acid-loaded nanoparticles for neural differentiation of trabecular meshwork mesenchymal stem cell

OBJECTIVES

This study aimed to fabricate the PCL-nanoparticles (NPs) loaded retinoic acid (RA) using the microfluidic system for successful cellular uptake and induction of neuronal differentiation of trabecular meshwork mesenchymal stem cells (TMMSCs).

METHODS

A microfluidic system used to synthesize RA-loaded NPs, DLS, FTIR, TEM, and UV-spectroscopy was recruited to characterize and study the release of RA. Also, the toxicity, cellular uptake, and neuronal differential of TMMSCs have been assessed.

RESULTS

According to the obtained results, the spherical NPs (117.6±0.35 nm, ‒19.4±5.3) and RA-loaded NPs (121.6±0.75 nm, ‒23.6±1.3) were synthesized successfully by microfluidic system. 7.8±2.04 % of RA was loaded in NPs, and 25 % was released in the first four hours. Thus, the NPs have been successfully internalized into the stem cells, leading to a significant increase in neural genes and protein (β Tubulin III and Map-2) expression.

CONCLUSION

Our study's harvested results have represented valid data for practical use of microfluidic systems in the term of NPs loaded RA synthesis and its successful function to cellular internalization and euronal differentiation of TMMSCs (Tab. 2, Fig. 10, Ref. 46).

Building a biopsychosocial model of cancer-related fatigue: the BIOCARE FActory cohort study protocol

Background

Cancer-related fatigue (CRF) is the most common side effect of cancer and cancer treatment. CRF prevalence is up to 50% in breast cancer patients and can continue several years after cancer remission. This persistent subjective sense of exhaustion is multifactorial. Numerous parameters have been evidenced to be related to CRF across biological, physical, psychological, social and/or behavioral dimensions. Although CRF has been studied for many years, the majority of previous studies focused on only one dimension, i.e., physical function. Moreover, few studies investigated CRF longitudinally with repeated measures. These are the two main obstacles that limit the understanding of CRF mechanisms. The purpose of this study is to create a biopsychosocial model of CRF with simultaneous and longitudinal anthropometric, clinical, biological, physical, psychological and sociological parameters.

Methods

BIOCARE FActory is a multicentric prospective study that will consist of an 18-month follow-up of 200 women diagnosed with breast cancer. Four visits will be scheduled at diagnosis, after treatments, and 12 and 18 months after diagnosis. The same procedure will be followed for each visit. Each session will be composed of anthropometric data collection, a semi-structured interview, cognitive tests, postural control tests, neuromuscular fatigability tests and a cardiorespiratory fitness test. Clinical and biological data will be collected during medical follow-ups. Participants will also complete questionnaires to assess psychological aspects and quality of life and wear an actigraphy device. Using a structural equation modeling analysis (SEM), collected data will build a biopsychosocial model of CRF, including the physiological, biological, psychological, behavioral and social dimensions of CRF.

Discussion

This study aims to highlight the dynamics of CRF and its correlates from diagnosis to post treatment. SEM analysis could examine some relations between potential mechanisms and CRF. Thus, the biopsychosocial model will contribute to a better understanding of CRF and its underlying mechanisms from diagnosis to the aftermaths of cancer and its treatments.

Trial registration

This study is registered at ClinicalTrials.gov (NCT04391543), May 2020.

The level of blood lead painter workers Rafsanjan city and its correlation with risk factors for cardiovascular disease in 2019

Introduction: Painters are exposed to various chemical harmful agents such as lead particles in paints. Some studies have suggested a possible association of occupational exposure that may cause cardiovascular effects. Lead is absorbed through the body through the skin, skin, and respiratory tract and penetrates some tissues. Considering the importance of labor health in each country's development and progress, this study was conducted to determine the amount of lead in the blood of painters in Rafsanjan in 2019. Materials and Methods: The present study is a cross-sectional study of the descriptive type conducted in 1397 on 77 painters of Rafsanjan city. Data collection was done in two stages, in the first stage, based on a checklist that included demographic information, and in the second stage by performing laboratory tests. Finally, by recording the data in SPSS software, quantitative data was reported as a "mean ± standard deviation" and qualitative information as a "number (percent)". Results: Of the 77 painter workers, the youngest is 21, and the oldest is 70 years old. A total of 20 people (26%) had a family history of heart attacks. The highest amount of lead in the blood of painters was reported to be 30.7 micrograms per deciliter, and the level of lead was most correlated with blood sugar. Sixty people (77.9%) painters used personal protective equipment. 49.4% of the study's painters wore work clothes, and 28.6% used gloves while working. Lead levels are directly related to blood sugar, cholesterol, triglyceride, LDL, age, work experience, and blood sugar levels were most correlated with the level of lead in painters' blood. Conclusion: This study's findings show that due to the increase in the work experience of painters, their blood lead level has also increased, and the blood sugar level has had the highest correlation with the lead level in the painters' blood.

External pH modulation during the growth of Vibrio tapetis, the aetiological agent of brown ring disease

AIMS

Brown ring disease (BRD) is an infection of the Manila clam Ruditapes philippinarum due to the pathogen Vibrio tapetis. During BRD, clams are facing immunodepression and shell biomineralization alteration. In this paper, we studied the role of pH on the growth of the pathogen and formulated hypothesis on the establishment of BRD by V. tapetis.

METHODS AND RESULTS

In this study, we monitored the evolution of pH during the growth of V. tapetis in a range of pH and temperatures. We also measured the pH of Manila clam haemolymph and extrapallial fluids (EPFs) during infection by V. tapetis. We highlighted that V. tapetis modulates the external pH during its growth, to a value of 7·70. During the development of BRD, V. tapetis also influences EPFs and haemolymph pH in vitro in the first hours of exposure and in vivo after 3 days of infection.

CONCLUSIONS

Our experiments have shown a close interaction between V. tapetis CECT4600, a pathogen of Manila clam that induces BRD, and the pH of different compartments of the animals during infection. These results indicate that the bacterium, through a direct mechanism or as a consequence of physiological changes encountered in the animal during infection, is able to interfere with the pH of Manila clam fluids. This pH modification might promote the infection process or at least create an imbalance within the animal that would favour its persistence. This last hypothesis should be tested in future experiment.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is the first observation of pH modifications in the context of BRD and might orient future research on the fine mechanisms of pH modulation associated with BRD.

Development of an accurate molecular mechanics model for buckling behavior of multi-walled carbon nanotubes under axial compression

In the present paper, an analytical solution based on a molecular mechanics model is developed to evaluate the elastic critical axial buckling strain of chiral multi-walled carbon nanotubes (MWCNTs). To this end, the total potential energy of the system is calculated with the consideration of the both bond stretching and bond angular variations. Density functional theory (DFT) in the form of generalized gradient approximation (GGA) is implemented to evaluate force constants used in the molecular mechanics model. After that, based on the principle of molecular mechanics, explicit expressions are proposed to obtain elastic surface Young's modulus and Poisson's ratio of the single-walled carbon nanotubes corresponding to different types of chirality. Selected numerical results are presented to indicate the influence of the type of chirality, tube diameter, and number of tube walls in detailed. An excellent agreement is found between the present numerical results and those found in the literature which confirms the validity as well as the accuracy of the present closed-form solution. It is found that the value of critical axial buckling strain exhibit significant dependency on the type of chirality and number of tube walls.

Theoretical infrared phonon modes in double-walled carbon nanotubes

In this theoretical work, we study the polarized infrared spectra of double-walled carbon nanotubes (DCNTs) as a function of their diameters, chiralities and lengths.

New beam monitoring tool for radiobiology experiments at the cyclotron ARRONAX

The ARRONAX cyclotron is able to deliver alpha particles at 68 MeV. In the frame of radiological research, a new method is studied to infer in situ the deposited dose: it is based on the online measurement of the bremsstrahlung (>1 keV) produced by the interaction of the incident particle with the medium. Experiments are made using bombarded poly(methyl methacrylate) (PMMA)-equivalent water targets in order to characterise this continuous X-ray spectrum. The intensity of the bremsstrahlung spectrum allows for the beam monitoring. A simulation code of the bremsstrahlung has been built, and a good agreement is found with the experimental spectra. With this simulation, it is possible to predict the sensibility of this method: it varies with the target thickness, showing a good sensibility for thin target (<1000 µm) and saturation for thicker ones. Bremsstrahlung spectrum also shows a sensibility on the target's chemical composition.

Improving neonatal complications with a structured multidisciplinary approach to gestational diabetes mellitus management

BACKGROUND

Gestational Diabetes Mellitus (GDM) is a common condition that affects pregnant women and may result in maternal as well as fetal and neonatal complications. Optimal coordinated management may reduce these complications if applied in team approach following generally accepted international guidelines.

METHODS

A retrospective analysis of the neonatal outcomes of GDM mothers who were followed in a tertiary medical center in the United Arab Emirates. The aim of the study was to assess the efficacy of a comprehensive and multidisciplinary GDM program which was applied to a quality improvement project. Clinical neonatal outcome indicators were compared at two time periods, one before the implementation in (2005-2006) and the other was following the initiation of this comprehensive multidisciplinary program in (2011-2012).

RESULTS

Follow up results revealed increased caesarian section and admission to neonatal intensive care unit. There was decreased incidence of macrosomia and a significant reduction of neonatal hypoglycemia in the newborn of GDM mothers. Overall rate of neonatal complications showed a significant improvement.

CONCLUSIONS

Implementing a structured comprehensive multidisciplinary program to manage GDM women has a positive impact on improving the care and outcomes of neonates.

Screening for neonatal hearing loss in the Eastern region of United Arab Emirates

The incidence of sensorineural hearing loss among infants in the neonatal intensive unit (NICU) is higher than in normal infants. This study determined the rate of hearing loss in healthy newborns and in NICU patients before hospital discharge at a single institution in the Eastern region of the United Arab Emirates; 96.5% of all eligible infants were screened. Hearing deficit was diagnosed in 25/13 854 healthy newborns (0.18%; 95% CI: 0.12%-0.27%) and 14/826 infants in the NICU (1.7%; 95% CI: 0.9%-2.8%). Although hearing impairment was significantly more common in those admitted to the NICU (RR = 9.4; 95% CI: 4.9-17.9), healthy newborns accounted for 25 of the 39 cases with hearing loss. The rate of congenital hearing deficit was comparable to international data. Universal screening is recommended since selective screening of high-risk infants missed two-thirds of newborns with hearing loss.

Does Alzheimer's disease with early onset progress faster than with late onset? A case-control study of clinical progression and cerebrospinal fluid biomarkers

BACKGROUND

Early-onset Alzheimer's disease (EOAD) is generally thought to have a more rapid course compared to late-onset Alzheimer's disease (LOAD). The faster progression of EOAD observed in some studies has also been thought to correlate with cerebrospinal fluid (CSF) biomarkers. Our clinical experience has not been suggestive of any difference in disease progression; therefore, we decided to investigate whether differences in clinical progression and CSF biomarkers between EOAD and LOAD could be demonstrated.

METHODS

Case-control study with 42 patients, 21 EOAD and 21 matched LOAD patients. Rates of progression were calculated and these, as well as CSF biomarker levels, were statistically compared.

RESULTS

There were no statistically significant differences in clinical progression between the EOAD group and the LOAD group. There was no significant difference in the absolute values of CSF biomarkers, but a tendency towards lower levels of β-amyloid in patients with EOAD was observed.

CONCLUSIONS

Our findings did not converge with results from the majority of previous studies, which have been suggestive of a faster clinical progression in EOAD. Possibly, the very strict algorithm by which our patients were matched explains our findings. However, the findings should be repeated in a larger study population.

Computation of the infrared active modes in single-walled boron nitride nanotube bundles

In this work, the infrared active modes are computed for homogeneous bundles of single-walled boron nitride nanotubes (BBNNTs), using the so-called spectral moments method. The dependence of the wavenumber on these modes in terms of diameters, lengths, and numbers of tubes, is investigated. To this end, use is made of a Lennard-Jones potential for describing the van der Waals interactions between tubes in a bundle. We find that, for a finite homogeneous bundle, additional modes appear as a specific signature. Finally, these results are useful for the interpretation of the experimental infrared spectra of BBNNTs.

Comparative evaluation of local and improved crop varieties through farmers’ participation on resource-poor farms in Afghanistan

The introduction of new crop varieties is important to improve farm productivity and increase food security in developing countries. This study was conducted to determine the performance of improved varieties of wheat (Triticum aestivum L.), rice (Oryza sativa L.), mungbean [(Vigna radiata (L.) Wilczek] and potato (Solanum tuberosum L.) in comparison to local varieties through farmers’ participatory evaluation. The study was conducted during three years (2006 to 2008) with 948 farmers’ participatory field trials across 18 districts in three Eastern provinces (Nangarhar, Laghman and Kunar) of Afghanistan. One or more improved varieties of wheat, rice, mungbean and potato were compared to the most popular local variety. Data were recorded on the grain yield of wheat, rice and mungbean, and the tuber yield of potato. On average, the improved varieties outyielded local varieties by 69, 57, 70 and 65% for wheat, rice, mungbean, and potato, respectively. Economic analysis in terms of net benefit demonstrated that the adoption of improved varieties resulted in additional incomes of US$ 1840, 1299, 574 and 790 ha-1 for wheat, rice, mungbean and potato, respectively. These findings underline the importance of on-farm farmers’ participatory technology evaluation in developing countries to disseminate new crop varieties to improve farm productivity.

Near-field probing of slow Bloch modes on photonic crystals with a nanoantenna

We study the near-field probing of the slow Bloch laser mode of a photonic crystal by a bowtie nano-aperture (BNA) positioned at the end of a metal-coated fiber probe. We show that the BNA acts as a polarizing nanoprobe allowing us to extract information about the polarization of the near-field of the slow-light mode, without causing any significant perturbation of the lasing process. Near-field experiments reveal a spatial resolution better than λ/20 and a polarization ratio as strong as 110. We also demonstrate that the collection efficiency is two orders of magnitude larger for the BNA than for a 200 nm large circular aperture opened at the apex of the same metal-coated fiber tip. The BNA allows for overcoming one of the main limitations of SNOM linked to the well-known trade off between resolution and signal-to-noise ratio.

Design and investigation of surface addressable photonic crystal cavity confined band edge modes for quantum photonic devices

We propose to use a localized Γ-point slow Bloch mode in a 2D-Photonic Crystal (PC) membrane to realize an efficient surface emitting source. This device can be used as a quantum photonic device, e.g. a single photon source. The physical mechanisms to increase the Q/V factor and to improve the directivity of the PC microcavity rely on a fine tuning of the geometry in the three directions of space. The PC lateral mirrors are first engineered in order to optimize photons confinement. Then, the effect of a Bragg mirror below the 2DPC membrane is investigated in terms of out-of-plane leakages and far field emission pattern. This photonic heterostructure allows for a strong lateral confinement of photons, with a modal volume of a few (λ/n)3 and a Purcell factor up to 80, as calculated by two different numerical methods. We finally discuss the efficiency of the single photon source for different collection set-up.

Simultaneous detection of 12 mycotoxins in cereals using RP-HPLC-PDA-FLD with PHRED and a post-column derivatization system

A new method for the simultaneous quantification of 12 mycotoxins was developed and optimized using reverse phase high performance liquid chromatography (RP-HPLC) with a photodiode array (PDA) and fluorescence detector (FLD), a photochemical reactor for enhanced detection (PHRED) and post-column derivatization. The mycotoxins included aflatoxins (AFB(1), AFB(2), AFG(1), and AFG(2)), ochratoxin A (OTA), zearalenone (ZEA), deoxynivalenol (DON), fumonisins (FB(1), FB(2), and FB(3)), T-2 and HT-2 toxins. A double sample extraction with a phosphate-buffered saline solution (PBS) and methanol was used for co-extraction of mycotoxins, and a multifunctional immunoaffinity column was used for cleanup. Optimum conditions for separation of the mycotoxins were obtained to separate 12 mycotoxins in FLD and PDA chromatograms with a high resolution. The method gave recoveries in the range 72-111% when applied to spiked corn samples. The limits of detection (LOD) were 0.025 ng/g for AFB(1) and AFG(1), 0.012 ng/g for AFB(2) and AFG(2), 0.2 ng/g for OTA, 1.5 ng/g for ZEA, 6.2 ng/g for FB(1), FB(3) and HT-2 toxin, 9.4 ng/g for FB(2) and T-2 toxin, and 18.7 ng/g for DON. In addition, the limits of quantification (LOQ) ranged from 0.04 ng/g for AFB(2) and AFG(2) to 62 ng/g for DON. The method was successfully applied to the determination of these mycotoxins in 45 cereal samples obtained from the Malaysian market. The results indicated that the method can be applied for the multi-mycotoxin determination of cereals.