Geochemical and biochemical evidence of lake overturn and fish-kill at Lake Averno, Italy.

Lake Averno is situated in the homonymous crater in the northwestern sector of the Campi Flegrei active volcanic system in Campania region, Italy. In February 2005 a fish kill event was observed in the lake, prompting a geochemical survey to ascertain the possible cause. In February 2005 a geochemical survey revealed that the lake water was unstratified chemically and isotopically, presumable, as a result of lake overturn. This fish-kill phenomenon was recorded at least two other times in the past. In contrast to the February 2005 results, data collected in October 2005, shows the Lake Averno to be stratified, with an oxic epilimnion (surface to 6 m) and an anoxic hypolimnion (6 m to lake bottom at about 33 m). Chemical and isotopic composition of Lake Averno waters suggests an origin by mixing of shallow waters with a Na-Cl hydrothermal component coupled with an active evaporation process. The isotopic composition of Dissolved Inorganic Carbon, as well as the composition of the non-reactive dissolved gas species again supports the occurrence of this mixing process. Decreasing levels of SO4 and increasing levels of H2S and CH4 contents in lake water with depth, strongly suggests anaerobic bacterial processes are occurring through decomposition of organic matter under anoxic conditions in the sediment and in the water column. Sulfate reduction and methanogenesis processes coexist and play a pivotal role in the anaerobic environment of the Lake Averno. The sulfate reducing bacterial activity has been estimated in the range of 14-22 μmol.m-2.day-1. Total gas pressure of dissolved gases ranges between 800 and 1400 mbar, well below the hydrostatic pressure throughout the water column, excluding the possibility, at least at the survey time, of a limnic eruption. Vertical changes in the density of lake waters indicate that overturn may be triggered by cooling of epilimnetic waters below 7°C. This is a possible phenomenon in winter periods if atmospheric temperatures remain frosty for enough time, as occurred in February 2005. The bulk of these results strongly support the hypothesis that fish kill was caused by a series of events that began with the cooling of the epilimnetic waters with breaking of the thermal stratification, followed by lake overturn and the rise of toxic levels of H2S from the reduced waters near the lake bottom

Ultrasensitive antibody-aptamer plasmonic biosensor for malaria biomarker detection in whole blood

Development of plasmonic biosensors combining reliability and ease of use is still a challenge. Gold nanoparticle arrays made by block copolymer micelle nanolithography (BCMN) stand out for their scalability, cost-effectiveness and tunable plasmonic properties, making them ideal substrates for fluorescence enhancement. Here, we describe a plasmon-enhanced fluorescence immunosensor for the specific and ultrasensitive detection of Plasmodium falciparum lactate dehydrogenase (PfLDH)—a malaria marker—in whole blood. Analyte recognition is realized by oriented antibodies immobilized in a close-packed configuration via the photochemical immobilization technique (PIT), with a top bioreceptor of nucleic acid aptamers recognizing a different surface of PfLDH in a sandwich conformation. The combination of BCMN and PIT enabled maximum control over the nanoparticle size and lattice constant as well as the distance of the fluorophore from the sensing surface. The device achieved a limit of detection smaller than 1 pg/mL (<30 fM) with very high specificity without any sample pretreatment. This limit of detection is several orders of magnitude lower than that found in malaria rapid diagnostic tests or even commercial ELISA kits. Thanks to its overall dimensions, ease of use and high-throughput analysis, the device can be used as a substrate in automated multi-well plate readers and improve the efficiency of conventional fluorescence immunoassays

Colorimetric Test for Fast Detection of SARS-CoV-2 in Nasal and Throat Swabs

Mass testing is fundamental to face the pandemic caused by the coronavirus SARS-CoV-2 discovered at the end of 2019. To this aim, it is necessary to establish reliable, fast, and cheap tools to detect viral particles in biological material so to identify the people capable of spreading the infection. We demonstrate that a colorimetric biosensor based on gold nanoparticle (AuNP) interaction induced by SARS-CoV-2 lends itself as an outstanding tool for detecting viral particles in nasal and throat swabs. The extinction spectrum of a colloidal solution of multiple viral-target gold nanoparticles-AuNPs functionalized with antibodies targeting three surface proteins of SARS-CoV-2 (spike, envelope, and membrane)-is red-shifted in few minutes when mixed with a solution containing the viral particle. The optical density of the mixed solution measured at 560 nm was compared to the threshold cycle (Ct) of a real-time PCR (gold standard for detecting the presence of viruses) finding that the colorimetric method is able to detect very low viral load with a detection limit approaching that of the real-time PCR. Since the method is sensitive to the infecting viral particle rather than to its RNA, the achievements reported here open a new perspective not only in the context of the current and possible future pandemics, but also in microbiology, as the biosensor proves itself to be a powerful though simple tool for measuring the viral particle concentration

Long term variations at Campi Flegrei (Italy) volcanic system highlighted by the monitoring of hydrothermal activity

Long time-series of chemical composition of fumaroles and of soil CO2 flux reveal that important variations in the activity of Solfatara fumarolic field, the most important hydrothermal site of Campi Flegrei, occurred in the 2000- 2008 period. A continuous increase of the CO2 concentration and a general decrease of the CH4 concentration are interpreted as the consequence of the increment of the relative amount of magmatic fluids, rich in CO2 and poor in CH4, hosted by the hydrothermal system. Contemporaneously the H2O-CO2-He-N2 gas system shows remarkable compositional variations in the samples collected after July 2000 with respect to the previous ones, indicating the progressive arrival at the surface of a magmatic component different from that involved in the 1983-84 bradyseism. The change starts in 2000 concurrently with the occurrence of relatively deep long periods seismic events which, in our interpretation, were the indicator of the opening of an easy pathway for the transfer of magmatic fluids towards the shallower, brittle domain hosting the hydrothermal system. Since 2000 this magmatic gas source is active and causes ground deformations, seismicity as well as the expansion of the area interested by diffuse soil degassing of deeply derived CO2

Adverse pregnancy outcomes in women at increased risk of preterm pre-eclampsia on first-trimester combined screening.

OBJECTIVE: Uteroplacental dysfunction may not only result in pre-eclampsia (PE) but also in preterm birth (PTB), small-for-gestational-age (SGA) birth and stillbirth. The aim of this study is to evaluate the positive predictive value (PPV) of first-trimester combined PE screening for all of these placenta-mediated adverse pregnancy outcomes. DESIGN: Retrospective cohort study. SETTING: Tertiary referral maternity unit. SAMPLE: A total of 13 211 singleton pregnancies. METHODS: First-trimester combined screening for preterm PE using the Fetal Medicine Foundation (FMF) algorithm. MAIN OUTCOMES MEASURES: Hypertensive disorders of pregnancy (HDP), PTB, SGA birth and stillbirth were combined to assess composite adverse and severe adverse pregnancy outcomes (CAPO and CAPO-S). The PPVs for CAPO and CAPO-S were calculated for women with a combined risk for preterm PE of ≥1 in 50 and ≥1 in 100. RESULTS: First-trimester combined screening identified 2215 women (16.8%) with a risk of ≥1 in 100 for preterm PE. The PPVs for a risk of ≥1 in 100 for CAPO and CAPO-S were 38.8% and 18.2%, respectively. The equivalent PPVs for a risk of ≥1 in 50 were 45.1% and 21.1%, respectively. CONCLUSIONS: Women identified at high risk of preterm PE are also at increased risk of other placenta-mediated adverse pregnancy outcomes, such as PTB, SGA birth and stillbirth. Women at high risk for preterm PE after first-trimester screening may benefit from a higher surveillance care pathway, with interventions to mitigate all the adverse outcomes associated with placental dysfunction

Multifunctional Core@Satellite Magnetic Particles for Magnetoresistive Biosensors

Magnetoresistive (MR) biosensors combine distinctive features such as small size, low cost, good sensitivity, and propensity to be arrayed to perform multiplexed analysis. Magnetic nanoparticles (MNPs) are the ideal target for this platform, especially if modified not only to overcome their intrinsic tendency to aggregate and lack of stability but also to realize an interacting surface suitable for biofunctionalization without strongly losing their magnetic response. Here, we describe an MR biosensor in which commercial MNP clusters were coated with gold nanoparticles (AuNPs) and used to detect human IgG in water using an MR biochip that comprises six sensing regions, each one containing five U-shaped spin valve sensors. The isolated AuNPs (satellites) were stuck onto an aggregate of individual iron oxide crystals (core) so that the resulting core@satellite magnetic particles (CSMPs) could be functionalized by the photochemical immobilization technique an easy procedure that leads to oriented antibodies immobilized upright onto gold. The morphological, optical, hydrodynamic, magnetic, and surface charge properties of CSMPs were compared with those exhibited by the commercial MNP clusters showing that the proposed coating procedure endows the MNP clusters with stability and ductility without being detrimental to magnetic properties. Eventually, the high-performance MR biosensor allowed us to detect human IgG in water with a detection limit of 13 pM (2 ng mL-1). Given its portability, the biosensor described in this paper lends itself to a point-of-care device; moreover, the features of the MR biochip also make it suitable for multiplexed analysis

Maternal ethnicity and socioeconomic deprivation: influence on adverse pregnancy outcomes.

OBJECTIVES: To evaluate the relative importance of ethnicity and socioeconomic deprivation in determining the likelihood and the percentage of composite adverse pregnancy outcomes (CAPO) and composite of severe adverse pregnancy outcomes (CAPO-S) METHODS: This is a single centre retrospective cohort study conducted in a tertiary maternity unit. Data regarding the ethnicity and socioeconomic deprivation were collected for 13,165 singleton pregnant women routinely screened in the first trimester for preeclampsia using the Fetal Medicine Foundation combined algorithm. RESULTS: The prevalence or risk of CAPO was 16.3% for White women, 29.3% for Black women and 29.3% for South Asian women. However, half of all CAPO cases (51.7%) occurred in White women. There is a strong interaction between ethnicity and socioeconomic deprivation (as measured with indices of multiple deprivation). Both influence the prevalence of CAPO and CAPO-S, with the contribution of ethnicity being strongest. CONCLUSIONS: Black and Asian ethnicity as well as socioeconomic deprivation influence the prevalence of placentally-mediated adverse pregnancy outcomes. Despite this, most adverse pregnancy outcomes occur in White women, who represent the majority of the population and are also affected by socioeconomic deprivation. For these reasons, inclusion of socioeconomic deprivation should be considered in early pregnancy risk assessment for placentally-mediated CAPO. This article is protected by copyright. All rights reserved

Prenatal prediction of adverse outcome using different charts and definitions of fetal growth restriction.

OBJECTIVE: Fetal growth assessment by ultrasound aims to identify small babies that are at higher risk of perinatal morbidity and mortality. The current study explores if the association between suboptimal fetal growth and adverse perinatal outcome varies with different definitions of fetal growth restriction and weight charts/standards. METHODS: This was a retrospective cohort study of 17261 singleton non-anomalous pregnancies from 24+0 weeks' gestation at a tertiary referral hospital. Estimated fetal weight (EFW) and Doppler indices were converted into gestational age specific centiles using a growth reference standard (Intergrowth-21) and various reference charts (Hadlock, Fetal Medicine Foundation [FMF] and Swedish). Test characteristics were assessed using definitions of FGR according to the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG), Society of Maternal and Fetal Medicine (SMFM) and Swedish criteria. Adverse perinatal outcome was defined as perinatal death, admission to the neonatal intensive care (NICU) at term, 5' Apgar score < 7, and therapeutic cooling for neonatal encephalopathy. The association between FGR according to different definitions and adverse perinatal outcome was compared. Multivariate logistic regression was used to investigate the strength of the associations between ultrasound parameters and adverse perinatal outcome. Ultrasound parameters were also tested for correlation. RESULTS: Intergrowth-21 (IG-21), Hadlock and FMF fetal size references classified 1.47%, 3.55% and 4.5% fetuses respectively as FGR using the ISUOG definition and 2.87%, 8.82% and 10.6% fetuses respectively using the SMFM definition. The sensitivity of each of the definition/chart combinations for adverse perinatal outcome varied from 4.4% (ISUOG definition with IG-21 charts) to 13.2% (SMFM definition with FMF charts). The concomitant specificity also varied from 89.4% (SMFM definition with FMF charts) to 98.6% (ISUOG definition with IG-21 charts). ISUOG and Swedish criteria showed the highest specificity, positive predictive value, and positive likelihood ratio in detecting adverse outcomes irrespective of which fetal size reference charts/standards were used. Conversely, the SMFM definition had the highest sensitivity across all investigated growth charts. Low estimated fetal weight, elevated uterine artery mean PI, abnormal umbilical artery PI and abnormal cerebro-placental ratio were all significantly associated with adverse perinatal outcome and there was positive correlation between the covariates. Multivariate logistic regression showed that uterine artery Doppler mean PI and smallness (EFW below the 5th centile) were the only parameters to be consistently associated with adverse outcome irrespective of definitions or fetal size growth charts used. CONCLUSIONS: The prevalence of FGR is variable based on the specific definition as well as the fetal size reference chart used to diagnose FGR. Irrespective of the method of classification, the sensitivity for the identification of adverse perinatal outcome remains low. Estimated fetal weight, uterine artery and fetal Dopplers are all significant predictors of adverse perinatal outcome. As these indices are correlated to each other, a prediction algorithm is advocated to overcome the limitations of using them in isolation. This article is protected by copyright. All rights reserved

Inclusion of a degron reduces levelsof undesired inteins after AAV-mediated proteintrans-splicing in the retina

Split intein-mediated protein trans-splicing expands AAV transfer capacity, thus overcoming the limited AAV cargo. However, non-mammalian inteins persist as trans-splicing by-products, and this could raise safety concerns for AAV intein clinical applications. In this study, we tested the ability of several degrons to selectively decrease levels of inteins after protein trans-splicing and found that a version of E. coli dihydrofolate reductase, which we have shortened to better fit into the AAV vector, is the most effective. We show that subretinal administration of AAV intein armed with this short degron is both safe and effective in a mouse model of Stargardt disease (STGD1), which is the most common form of inherited macular degeneration in humans. This supports the use of optimized AAV intein for gene therapy of both STGD1 and other conditions that require transfer of large genes

Escalating CO2 degassing at the Pisciarelli fumarolic system, and implications for the ongoing Campi Flegrei unrest

This short communication aims at providing an updated report on degassing activity and ground deformation variations observed during the ongoing (2012–2019) Campi Flegrei caldera unrest, with a particular focus on Pisciarelli, currently its most active fumarolic field. We show that the CO2 flux from the main Pisciarelli fumarolic vent (referred as “Soffione”) has increased by a factor > 3 since 2012, reaching in 2018–2019 levels (>600 tons/day) that are comparable to those typical of a medium-sized erupting arc volcano. A substantial widening of the degassing vents and bubbling pools, and a further increase in CO2 concentrations in ambient air (up to 6000 ppm), have also been detected since mid-2018. We interpret this escalating CO2 degassing activity using a multidisciplinary dataset that includes thermodynamically estimated pressures for the source hydrothermal system, seismic and ground deformation data. From this analysis, we show that degassing, deformation and seismicity have all reached in 2018–2019 levels never observed since the onset of the unrest in 2005, with an overall uplift of ~57 cm and ~448 seismic events in the last year. The calculated pressure of the Campi Flegrei hydrothermal system has reached ~44 bar and is rapidly increasing. Our results raise concern on the possible evolution of the Campi Flegrei unrest and reinforce the need for careful monitoring of the degassing activity at Pisciarelli, hopefully with the deployment of additional permanent gas monitoring units