Late Peak Research Articles

Carbonate system variability in the Mediterranean Sea: a modelling study

A basin-scale Mediterranean carbonate system model has been setup, building on the POSEIDON operational biogeochemical model. The spatial variability of carbonate system variables from a 13-year simulation (2010-2022) was validated against CARIMED in situ data (DIC, TA, pCO2), showing reasonable agreement in reproducing the observed patterns and preserving the dynamics in different areas, except a slight overestimation (~15 µmol/kg) of TA in the Eastern Levantine. The time-variability of model outputs (DIC, TA, pCO2, pH) was validated, against available time-series from Western (DYFAMED, Villefranche-PointB) and Eastern Mediterranean (HCB) sites, showing good agreement with the data, particularly for pCO2, pH and DIC. The model failed to reproduce the observed late summer peak of TA at DYFAMED/PointB sites, which may be partly attributed to the advection of lower alkalinity Atlantic water in the area. The seasonal variability of DIC and pCO2@20°C was found to be mainly controlled by winter mixing and the subsequent increase of primary production and net CO2 biological uptake, which appeared overestimated at HCB. Along with the reference simulation, three sensitivity simulations were performed, de-activating the effect of biology, evaporation and CO2 air-sea fluxes on DIC and TA, in order to gain insight on the processes regulating the simulated carbonate system variability. The effect of biological processes on DIC was found more significant (peak during spring) in the more productive North Western Mediterranean, while evaporation had a stronger impact (peak during late summer) in the Levantine basin. CO2 air-sea flux was higher in the Western Mediterranean, particularly the Gulf of Lions and Alboran Sea, as well as in river influenced areas, such as the N. Adriatic and along the pathway of the Black Sea Water in the Aegean. A weak release of CO2 was found in the Eastern Levantine and Libyan Sea. Its basin average (+2.1 mmol/m2/day) and positive trend (+0.1 mmol/m2/day/year) indicates a gradually increasing net CO2 ocean uptake. The simulated positive trends of DIC (0.77 μmol/kg/year) and TA (0.53 μmol/kg/year) in the North Western Mediterranean were consistent with observational and modelling studies, in constrast with the Levantine basin, where no significant trends were found for TA.

An Intense Out-of-Season Rebound of Influenza Activity After the Relaxation of Coronavirus Disease 2019 Restrictions in Beijing, China.

The aim of this study was to investigate the changes of epidemic characteristics of influenza activity pre- and post-coronavirus disease 2019 (COVID-19) in Beijing, China. Epidemiologic data were collected from the influenza surveillance system in Beijing. We compared epidemic intensity, epidemic onset and duration, and influenza transmissibility during the 2022-2023 season with pre-COVID-19 seasons from 2014 to 2020. The overall incidence rate of influenza in the 2022-2023 season was significantly higher than that of the pre-COVID-19 period, with the record-high level of epidemic intensity in Beijing. The onset and duration of the influenza epidemic period in 2022-2023 season was notably later and shorter than that of the 2014-2020 seasons. Maximum daily instantaneous reproduction number (Rt) of the 2022-2023 season (Rt = 2.31) was much higher than that of the pre-COVID-19 period (Rt = 1.49). The incidence of influenza A(H1N1) and A(H3N2) were the highest among children aged 0-4 years and 5-14 years, respectively, in the 2022-2023 season. A late, intense, and short-term peak influenza activity was observed in the 2022-2023 season in Beijing. Children <15 years old were impacted the most by the interruption of influenza circulation during the COVID-19 pandemic. Maintaining continuous surveillance and developing targeted public health strategies of influenza is necessary.

Driving factors analysis and scenario prediction of CO2 emissions in power industries of key provinces along the Yellow River based on LMDI and BP neural network

IntroductionPower industry is one of the largest sources of CO2 emissions in China. The Yellow River Basin plays a supportive role in guaranteeing the effective supply of electricity nationwide, with numerous power generation bases. Understanding the drivers and peak of CO2 emissions of power industry in the Yellow River Basin is vital for China to fulfill its commitment to reach carbon emissions peak by 2030.MethodsThe Logarithmic Mean Divisia Index (LMDI) model was employed to explore the drivers to the change of CO2 emissions in power industries of three study areas, including Inner Mongolia Autonomous Regions, Shanxi Province, and Shandong Province in the Yellow River Basin. And Back Propagation (BP) neural network was combined with scenario analysis to empirically predict the trend of the amount of CO2 emitted by power industry (CEPI) from provincial perspective.ResultsCEPI in Inner Mongolia under the scenarios of a low degree of CO2 emissions promotion with a medium degree of CO2 emissions inhibition (LM) and a low degree of CO2 emissions promotion with a high degree of CO2 emissions inhibition (LH) scenario can reach a peak as early as 2030, with the peak value of 628.32 and 638.12 million tonnes, respectively. Moreover, in Shanxi, only CEPI under a low degree of CO2 emissions promotion scenarios (LL, LM, LH) can achieve the peak in 2025 ahead of schedule, with amounts of 319.32, 308.07, and 292.45 million tonnes. Regarding Shandong, CEPI under scenarios of a low degree of CO2 emissions promotion with a high degree of CO2 emissions inhibition (LH) and a medium degree of CO2 emissions promotion with a high degree of CO2 emissions inhibition (MH) could achieve the earliest peak time in 2025, with a peak of 434.6 and 439.36 million tonnes, respectively.DiscussionThe earliest peak time of CEPI in Shandong Province and Shanxi Province is 2025, but the peak of CEPI in Shanxi is smaller than that of Shandong. The peak time of CEPI in Inner Mongolia is relatively late, in 2030, and the peak is larger than that of the other two provinces. The per capita GDP is the most positive driving factor that contributes to the CEPI. Shandong has a strong economy, and its per capita GDP is much higher than Shanxi’s. Therefore, even under the same peak time, the CEPI in Shandong is much higher than that of Shanxi. Inner Mongolia is extensive and sparsely populated, which makes its per capita GDP rank among the top in China. In addition, Inner Mongolia’s coal-based power generation structure and high power generation also contribute to its late CO2 peak time and large CO2 peak.

Detrital zircons and heavy minerals from the Palu Formation, Sulawesi, Indonesia: constraints on exhumation of the Palu Metamorphic Complex and drainage evolution

The Palu Formation, previously known as the Celebes Molasse in the Palu area, is understudied and was previously considered to be associated with the Pliocene collision between an Australian-derived microcontinent (Banggai Sula) and the eastern margin of Sundaland (West Sulawesi). Here, we present sedimentological, heavy mineral and zircon geochronological data to provide insights into sediment provenance and to elucidate Neogene tectonic activity in Sulawesi. These analyses suggest that the Pleistocene Palu Formation comprises synorogenic alluvial fan to braided river deposits that record the rapid uplift of metamorphic and granitoid rocks in the Neck and west Central Sulawesi. The Palu Formation is characterized by predominant granitoid and metamorphic clasts and heavy mineral assemblages dominated by pyroxene, amphibole and garnet. Detrital zircons record youngest grain ages of c. 2.5 and 3.0 Ma with a significant Pliocene age population and subsidiary Eocene, Cretaceous, Jurassic and Late Triassic age peaks. Rapid uplift and erosion associated with mountain building shaped the topography and influenced the evolution of Palu River networks. Supplementary material : Complete location, heavy mineral and detrital zircon geochronology datasets are available at https://doi.org/10.6084/m9.figshare.c.7033388 Thematic collection: This article is part of the Mesozoic and Cenozoic tectonics, landscape and climate change collection available at: https://www.lyellcollection.org/topic/collections/mesozoic-and-cenozoic-tectonics-landscape-and-climate-change

Sub-daily scale variations and trends in southwest monsoon rainfall over the West coasts of India and Myanmar

The West Coast of India (WCI) and the West Coast of Myanmar (WCM) receive a good amount of monsoon rainfall due to the orographic lifting and moisture transport from the neighbouring sea. Here, diurnal variation in rainfall amount, frequency, intensity, and contribution during the summer monsoon period was studied using TRMM 3 hourly precipitation data. The analysis was carried out over lowland, midland and highland regions of both the coasts. The subregions exhibit a similar diurnal pattern even though the intensity and frequency of rainfall vary from region to region. Generally, bimodal variations with late afternoon and early morning peaks are found over lowland and midland regions of both WCI and WCM in rainfall frequency, amount and contribution. However, highland regions exhibit unimodal variation with a single late afternoon peak. Over WCI, lowland regions exhibit primary peak during early morning, whereas lowlands of WCM exhibit primary peak during afternoon hours. Rainfall intensity exhibits a different pattern compared to other parameters. Rainfall intensity increases from south to north over both the coasts. Among the subregions, maximum rainfall intensity is found over midlands and minimum over highlands. In general, more rainfall is observed over subregions of WCM than subregions of WCI. Most of the lowland and midland regions, exhibit a significant increasing trend in rainfall frequency and contribution at morning hours and a significant decreasing trend at afternoon hours. Rainfall frequency exhibit different periodicities during different time indicating interannual heterogeneity in rainfall. The diurnal pattern of summer monsoon rainfall over the Indian and Myanmar West coasts shows remarkable latitudinal and topographical variations.

Structure and functioning of plankton communities оf the Rybinsky Reservoir under the conditions of climate change

Based on the data of complex environmental studies, which have been regularly carried out at six standard stations of the Rybinsk Reservoir since the middle of the 20th century, the orientation of changes in the elements of the reservoir ecosystem associated with global climatic events has been analyzed. During the period of climate warming, which began in 1977 and continues into the 21st century, the air temperature in the warm season increased by 0.9°C, the water temperature by 1.4°C, the average annual inflow by 7.5%, and the duration of the ice-free period by two weeks. An increase in electrical conductivity and color of water, a decrease in transparency were noted. With significant interannual variations in biological characteristics, in the XXI century, the number of bacterioplankton increased by 1.7 times, and bacterial production doubled. Chlorophyll content increased by 1.4 times and values 15 µg/L reflecting the eutrophic state of the reservoir began to be observed more often. In the biomass of phytoplankton, the proportion of small cell forms increased. The total abundance of phytoplankton increased due to the development of cyanobacteria, which form a long summer maximum in the seasonal dynamics of the community. The increase in water mineralization promoted the progressive spread of alien brackish-water algae. Biomass of zooplankton increased by 2.5 times. An increase in the abundance of crustaceans (Cladocerans, by 1.6 times; Copepods, by 1.9 times) caused a change in the structure of zooplankton and the formation of a strong late summer peak of biomass. The intensification of hydrobiological processes was clearly manifested after the abnormally hot 2010, the conditions of which not only stimulated the development of plankton communities, but also but also caused the formation of oxygen deficiency in the bottom layers. Warming has significantly transformed the ecosystem of the Rybinsk Reservoir, intensified eutrophication processes and worsened water quality. Changes in hydrometeorological characteristics have gone beyond the mild scenario of climate warming.

A distinct immune cytokine profile is associated with morning cortisol and repeated stress.

The objective of this study was to investigate possible immune cytokine trends throughout a week-long surgical simulation mass-casualty training session in order to determine the effects of stress inoculation on the immune system. Thirty-seven military medical students participated in a hyper-realistic surgical simulation training event conducted at Strategic Operations site in San Diego, California. Salivary samples were collected every morning of the stress training exercise for 4 consecutive days. Cortisol, along with a panel of 42 immune cytokines, was measured using multiplex enzyme-linked immunosorbent assays from Eve Technologies. The determined concentrations were averaged and plotted on a scatter plot, and then points were fit to a second-order polynomial trendline of best fit to measure. The cytokines epidermal growth factor, growth-related oncogene-α, interleukin (IL)-1α, and platelet-derived growth factor-AA followed a noted pattern of cortisol decrease throughout the week. In addition, cytokines IL-27, granulocyte colony stimulating factor, IL-10, and IL-13 demonstrated a late peak, followed by a return to baseline at the conclusion of training. Finally, the cytokine monocyte chemoattractant protein-1 displayed a decline throughout the week followed by an increase on the last day of stress training. Altogether, these results help to identify important biomarkers that may help to improve long-term stress adaptation and prevent post-traumatic stress disorder following exposure to repeated stress.

Cretaceous magmatism in the northern Lhasa Terrane: Implications for the tectonic evolution and crustal growth tempos of central Tibet

The subduction and demise of an ocean plate are generally recognized as essential processes that result in the reworking and maturation of the continental crust. The northern Lhasa Terrane in central Tibet represents the forefront of the Lhasa-Qiangtang collision belt following the closure of the Bangong-Nujiang Ocean. Thus, it is a pivotal location to study the transition processes from oceanic lithosphere subduction to continental collision as well as pertinent crustal growth mechanisms. Here, we present zircon U-Pb dating, whole-rock major and trace element and Sr-Nd isotope, and zircon Hf isotope and trace element data of the Mendang igneous complex, Baingoin County, northern Lhasa Terrane. Geochronological results show that the granodiorites, trachydacites, and rhyolites in the Mendang igneous complex formed at ca. 122−116 Ma, 97 Ma, and 73 Ma, respectively. The Early Cretaceous granodiorite samples are peraluminous with high SiO2, Al2O3, and K2O contents, and moderate A/CNK (molar ratio of Al2O3/[CaO + Na2O + K2O]) values, which are similar to those of typical felsic peraluminous I-type granites. The granodiorites are characterized by enrichment in light rare earth elements and large ion lithophile elements (e.g., Rb) and depletion in high field strength elements (e.g., Nb, Ta). They also show the most enriched whole-rock Sr-Nd [(87Sr/86Sr)i = 0.7072−0.7078; εNd(t) = −7.60 to −5.08] and zircon Hf [εHf(t) = −4.46 to +1.02] isotope compositions, indicating that the Early Cretaceous granodiorites were likely derived from an ancient basement under a subduction setting. The trachydacites have uniform SiO2, high Al2O3, Sr contents, and Sr/Y values, and low Y and Yb contents, belonging to adakitic rocks. They show more depleted whole-rock Sr-Nd [(87Sr/86Sr)i = 0.7065−0.7066; εNd(t) = −0.56 to −0.22] and zircon Hf [εHf(t) = 4.36−7.84] isotopes than the granodiorites, suggesting that the trachydacites may have generated from partial melting of the juvenile thickened lower continental crust. The rhyolites have the highest SiO2 and K2O contents in the Mendang igneous complex, and significant depletion of Ba, Sr, Eu, P, and Ti. They have slighter more enriched whole-rock Nd [εNd(t) = −3.71 to −1.16] and zircon Hf [εHf(t) = 1.03−4.31] isotope compositions than the trachydacites. These features suggest that the rhyolites were highly fractionated products of the crustal melts. Whole-rock Sr-Nd and zircon Hf isotopes of the Mendang igneous complex show a kink trend from enrichment to depletion and then transfer to enrichment again, signifying an increased contribution of juvenile materials in the northern Lhasa Terrane toward progressively replacing the ancient lower crust and accumulating to newly formed crust. The estimated crustal thickness beneath the northern Lhasa Terrane shows a sharp increase from the Early to Late Cretaceous and peak at ca. 97 Ma, whereas it largely decreases in the Late Cretaceous. Integrated with previous studies, we propose that the formation of the Mendang igneous complex (122−73 Ma) elaborately documents the regional tectonic transition from oceanic lithosphere subduction to demise as well as continental crustal differentiation and maturation. The rollback and breakoff of the southward subducted Bangong-Nujiang oceanic slab in the Early Cretaceous initiated diverse magmatism in the northern Lhasa Terrane. During the early Late Cretaceous, the widespread adakitic and Mg-rich magmatism was attributed to the delamination of the thickened lithosphere following the final amalgamation of the Lhasa and Qiangtang Terranes. In the late Late Cretaceous, post-collisional extension induced the formation of the rhyolites in the northern Lhasa Terrane. The growth and destruction of the continental crust had certain tempos from the oceanic lithosphere subduction to continental post-collision stage.

Post-cardiac arrest temporal evolution of left ventricular function in a rat model: speckle-tracking echocardiography and cardiac circulating biomarkers.

There is little information from experimental studies regarding the evolution of post-resuscitation cardiac arrest [post-return of spontaneous circulation (post-ROSC)] myocardial dysfunction during mid-term follow-up. For this purpose, we assessed left ventricular (LV) function and circulating cardiac biomarkers at different time points in a rat model of cardiac arrest (CA). Rats were divided into two groups: control and post-ROSC rats. Eight minutes of untreated ventricular fibrillation were followed by 8 min of cardiopulmonary resuscitation. Conventional and speckle-tracking echocardiographic (STE) parameters and cardiac circulating biomarkers concentrations were assessed, at 3, 4, 72, and 96 h post-ROSC. At 3 and 4 h post-ROSC, LV systolic function was severely impaired, and high-sensitivity cardiac troponin T and N-terminal pro-atrial natriuretic peptide (NT-proANP) plasma concentrations were significantly increased, compared with control rats (P < 0.0001 for all). At 72 and 96 h post-ROSC, LV ejection fraction (LVEF) normalized. At 96 h, the following variables were significantly different from control rats: early trans-mitral peak velocity, 56.8 ± 3.1 vs. 87.8 ± 3.8 cm/s, P < 0.0001; late trans-mitral peak velocity, 50.6 ± 4.7 vs. 73.7 ± 4.2 cm/s, P < 0.0001; mean s' wave velocity, 4.6 ± 0.3 vs. 5.9 ± 0.3 cm/s, P < 0.0001, global longitudinal strain (GLS) -7.5 ± 0.5 and vs. -11 ± 1.2%, P < 0.01; GLS rate (GLSR) -0.9 ± 0.4 and -2.3 ± 0.2 1/s, P < 0.01; and NT-proANP concentration, 2.5 (0.2; 6.0) vs. 0.4 (0.01; 1.0) nmol/L, P < 0.01. s' velocity, GLS, and GLSR indicated that LV systolic function was still impaired 96 h post-ROSC. These findings agree with NT-proANP concentrations, which continue to be high. Normalization of LVEF supports the use of STE for its greater sensitivity for monitoring post-CA cardiac function. Further investigations are needed to provide evidence of the post-ROSC LV diastolic function pattern.

Black Carbon and Traffic-Related PM2.5 in Bangkok Area

This study was to investigate level of black carbon (BC) in urban areas of Bangkok, Thailand. Hourly BC concentrations were measured at two stations (operated by PCD), i.e., Bangna station and Thonburi station (roadside) during dry season by using the aethalometer (Model AE-42). The averages of hourly BC concentrations observed were 5.1±2.9 and 4.3±1.9 µg/m3, respectively. The diurnal pattern of BC levels obtained from two stations exhibited two peaks of BC concentrations occurring in the morning (0500 to 0800 LST) and late evening (2100 to 2300 LST), which the late evening peaks were higher than the morning ones. The morning peaks of BC were evidently influenced by traffic condition, while the evening peaks were possibly related to traffic associated with meteorological effects. BC concentrations from roadside stations (Thonburi) were higher than those from Bangna station possibly due to less distance of sampling equipment from roads. There was some difference of BC concentrations observed between during weekday and weekends, particularly, at roadside station (Thonburi station). In addition, increase of diesel vehicles proportion, particularly in the nighttime, contributed to higher BC concentrations. The relationships among BC concentration, air pollutants (PM2.5), vehicle fleets and meteorological variables were found.

FIB-4 liver fibrosis index correlates with aortic valve sclerosis in non-alcoholic population.

Hepatic fibrosis, a progressive scarring of liver tissue, is commonly caused by non-alcoholic fatty liver disease (NAFLD), which increases the risk of cardiovascular disease. The Fibrosis-4 (FIB-4) index is a non-invasive tool used to assess liver fibrosis in patients with NAFLD. Aortic valve sclerosis (AVS), a degenerative disorder characterized by thickening and calcification of valve leaflets, is prevalent in the elderly and associated with increased cardiovascular morbidity and mortality. Recent studies have suggested that AVS may also be linked to other systemic diseases such as liver fibrosis. This study aimed to investigate the relationship between the FIB-4 index and AVS in a non-alcoholic population, with the hypothesis that the FIB-4 index could serve as a potential marker for AVS. A total of 92 patients were included in this study. AVS was detected using transthoracic echocardiography, and patients were divided into groups according to the presence of AVS. The FIB-4 index was calculated for all patients and compared between the groups. A total of 17 (18.4%) patients were diagnosed AVS. Patients with AVS had higher rates of diabetes mellitus, older age, hypertension, angiotensin-converting enzyme inhibitor use, higher systolic blood pressure (BP) and diastolic BP in the office, coronary artery disease prevalence, left atrial volume index (LAVI), left ventricular mass index (LVMI), and late diastolic peak flow velocity (A) compared to those without AVS. Moreover, AVS patients had significantly higher creatinine levels and lower estimated glomerular filtration rate. Remarkably, the FIB-4 index was significantly higher in patients with AVS. In univariate and multivariate analyses, higher systolic BP in the office (OR, 1.044; 95% CI 1.002-1.080, p=.024) and higher FIB-4 index (1.46±.6 vs. .91±.46, p<.001) were independently associated with AVS. Our findings suggest that the FIB-4 index is associated with AVS in non-alcoholic individuals. Our results highlight the potential utility of the FIB-4 index as a non-invasive tool for identifying individuals at an increased risk of developing AVS.

Impacts of anthropogenic emissions and meteorology on spring ozone differences in San Antonio, Texas between 2017 and 2021

San Antonio has been designated as ozone nonattainment under the current National Ambient Air Quality Standards (NAAQS). Ozone events in the city typically occur in two peaks, characterized by a pronounced spring peak followed by a late summer peak. Despite higher ozone levels, the spring peak has received less attention than the summer peak. To address this research gap, we used the Weather Research and Forecasting (WRF)-driven GEOS-Chem (WRF-GC) model to simulate San Antonio's ozone changes in the spring month of May from 2017 to 2021 and quantified the respective contributions from changes in anthropogenic emissions and meteorology. In addition to modeling, observations from the San Antonio Field Studies (SAFS), the Texas Commission on Environmental Quality (TCEQ) Continuous Ambient Monitoring Stations (CAMS), and the spaceborne TROPOspheric Monitoring Instrument (TROPOMI) are used to examine and validate changes in ozone and precursors. Results show that the simulated daytime mean surface ozone in May 2021 is 3.8 ± 0.6 ppbv lower than in May 2017, which is slightly less than the observed average differences of −5.3 ppbv at CAMS sites. The model predicted that the anthropogenic emission-induced changes contribute to a 1.4 ± 0.5 ppbv reduction in daytime ozone levels, while the meteorology-induced changes account for a 2.4 ± 0.6 ppbv reduction over 2017–2021. This suggests that meteorology plays a relatively more important role than anthropogenic emissions in explaining the spring ozone differences between the two years. We additionally identified (1) reduced NO2 and HCHO concentrations as chemical reasons, and (2) lower temperature, higher humidity, increased wind speed, and a stronger Bermuda High as meteorological reasons for lower ozone levels in 2021 compared to 2017. The quantification of the different roles of meteorology and ozone precursor concentrations helps understand the cause and variation of ozone changes in San Antonio over recent years.

Heterogeneity in glycaemic control in children and adolescents with type 1 diabetes: A latent class trajectory analysis of Danish nationwide data.

Suboptimal glycaemic control in children and adolescents with type 1 diabetes is prevalent and associated with increased risk of diabetes-related complications and mortality later in life. First, we aimed to identify distinct glycated haemoglobin (HbA1c) trajectories in children and adolescents (2-19 years) with type 1 diabetes. Second, we examined their associations with clinical and socio-demographic factors. Data were obtained from the Danish Registry of Childhood and Adolescent Diabetes (DanDiabKids) comprising all Danish children and adolescents diagnosed with type 1 diabetes from 1996 to 2019. Subgroups of distinct mean trajectories of HbA1c were identified using data-driven latent class trajectory modelling. A total of 5889 children (47% female) had HbA1c measured a median of 6 times (interquartile range 3-8) and contributing to 36,504 measurements. We identified four mean HbA1c trajectories, referred to as 'Stable but elevated HbA1c' (83%), 'Increasing HbA1c' (5%), 'Late HbA1c peak' (7%), and 'Early HbA1c peak' (5%). Compared to the 'Stable but elevated HbA1c' group, the three other groups presented rapidly deteriorating glycaemic control during late childhood or adolescence, had higher HbA1c at study entry, and included fewer pump users, higher frequency of inadequate blood glucose monitoring, more severe hypoglycaemic events, lower proportions with Danish origin, and worse educational status of parents. The groups also represented significant differences by healthcare region. Children and adolescents with type 1 diabetes experience heterogenous trajectories with different timings and magnitudes of the deterioration of HbA1c levels, although the majority follow on average a stable, yet elevated HbA1c trajectory. The causes and long-term health implications of these heterogenous trajectories need to be addressed.

Heavy metal load in waters and sediments of Karamana River Basin, southwestern India: A COVID-19 lockdown modulation

Rapid urbanization and industrialization jointly provoked heavy metal contamination in surface water (SW) and channel sediments (CS) of the riverine ecosystem especially in developing countries like India. Water and sediments are to be considered the most vital gears and useful indicators of the level of contamination in an aquatic environment. Furthermore, it is imperative to assess how COVID 19 lockdown, influenced the Karamana River Basin (KRB) waters catering to the quality water needs of urbanites of a city like Thiruvananthapuram, the capital of Kerala. For an insight into this issue, 84 samples (water = 41; sediment = 41) were collected during the pre-monsoon (i.e., January) of 2021 and 2022 and analysed to generate heavy metal concentration levels in the samples. Our estimate of the Heavy Metal Pollution Index (HPI) of water in the KRB in 2021, during the late peak of Covid-19, indicates that though ∼78.89% of the basin (553.78 km2) stayed within the non-contaminated category, and ∼21.11% (or 148.22 km2) was in the contaminated or very poor category. Contrarily, in 2022 after the withdrawal of lockdown restrictions, the non-contaminated area sharply declined to ∼45.04% (316.15 km2) of the basin and the contaminated area rose to 54.96% (385.85 km2). Furthermore, the Inverse Distance Weighted (IDW) modeling strongly supports that Cr and Fe are the leading heavy metal polluters in the Karamana River (KR) waters during 2021 and 2022. Subsequently, estimated Igeo values in sediments indicate that the uncontaminated area has reduced from 88.89% to 83.73%, and the uncontaminated to the moderately contaminated area rose to 5.16%. Therefore, the shutdown of anthropogenic activities, including small- and medium-scale industries as part of the COVID-19 lockdown, improved the surface water quality of KRB for a short-stint of time, but swung back to normality just after the lifting of lockdown restrictions.

Biventricular intraventricular mechanical and electrical dyssynchrony in pulmonary arterial hypertension

BackgroundPulmonary arterial hypertension (PAH) leads to myocardial remodeling, manifesting as mechanical dyssynchrony (M-dys) and electrical dyssynchrony (E-dys), in both right (RV) and left ventricles (LV). However, the impacts of layer-specific intraventricular M-dys on biventricular functions and its association with E-dys in PAH remain unclear. MethodsSeventy-nine newly diagnosed patients with PAH undergoing cardiac magnetic resonance scanning were consecutively recruited between January 2011 and December 2017. The biventricular volumetric and layer-specific intraventricular M-dys were analyzed. The QRS duration z-scores were calculated after adjusting for age and sex. Results77.22 % of patients were female (mean age 30.30 ± 9.79 years; median follow-up 5.53 years). Further, 29 (36.71 %) patients succumbed to all-cause mortality by the end of the study. At the baseline, LV layer–specific intraventricular M-dys had apparent transmural gradients compared with RV in the radial and circumferential directions. However, deceased patients lost the transmural gradients. The LV longitudinal strain rate time to late diastolic peak in the myocardial region (LVmyoLSRTTLDPintra) predicted long-term survival. The Kaplan–Meier curve revealed that patients with PAH with LVmyoLSRTTLDPintra <20.01 milliseconds had a worse prognosis. Larger right ventricle (RV) intraventricular M-dys resulted in worse RV ejection fraction. However, larger LV intraventricular M-dys in the late diastolic phase indicated remarkable exercise capacity and higher LV stroke volume index. E-dys and intraventricular M-dys had no direct correlations. ConclusionsThe layer-specific intraventricular M-dys had varying impacts on biventricular functions in PAH. PAH patients with LVmyoLSRTTLDPintra <20.01 milliseconds had a worse prognosis. LV intraventricular M-dys in the late diastolic phase needs more attention to precisely evaluate LV function.

Noninvasive Evaluation of Central Haemodynamic Parameters

Ageing is one of the relevant cardiovascular risk factors. Non-invasive assessment of cardiac function is an important approach in preventive medicine. The aim of our study was to evaluate the effect of age and gender on central haemodynamics. Seventy-six clinically healthy individuals were divided into four groups according to their age and gender. Applanation tonometry was applied using Sphygmocor device (AtCor, Australia). Pulse wave analysis was utilized for non-invasive assessment of central pressures (systolic, diastolic, mean, pulse, augmentation and end-systolic). Several important derivative indices such as augmentation index AIx75 $$(\frac{\rm Augmentation\ pressure}{\rm Pulse\ pressure}\times 100$$, corrected for heart rate 75 beats/minute), arterial elastance (Ea,$$\frac{\rm End - systolic\ pressure}{\rm Stroke\ volume})$$ and wasted effort (Ew) were computed. Ew is the ventricular force that is generated to overcome the late systolic peak and does not contribute to an increased stroke volume. Arterial stiffening was confirmed by the significantly higher central systolic and pulse pressures, AIx75 and arterial elastance in the middle-aged groups ($$P&lt;0.01$$). Those alterations were most pronounced in middle-aged females in support to the concept for a postmenopausal effect of female gender beyond ageing. We have shown a positive correlation between Ew and Ea valid only for the middle-aged individuals ($$R=0.70$$, $$P&lt;0.001$$) that coincided with similar correlation between Ea and AIx75 for the same age groups ($$R=0.53$$, $$P&lt;0.001$$). Our supposition is that arterial stiffening contributes to the elevation of the `pulsatile' afterload thus impairing vascular/ventricular coupling and increasing myocardial load and oxygen demands. In conclusion, applanation tonometry and PWA provide reliable measures of central haemodynamics and myocardial afterload.

LC-MS Approach to Decipher a Light Chain Chromatographic Peak Splitting of a Monoclonal Antibody.

Monoclonal antibodies (mAbs), like other protein therapeutics, are prone to various forms of degradation, some of which are difficult to distinguish from the native form yet may alter potency. A generalizable LC-MS approach was developed to enable quantitative analysis of isoAsp. In-depth understanding of product quality attributes (PQAs) enables optimization of the manufacturing process, better formulation selection, and decreases risk associated with product handling in the clinic or during shipment. Reversed-phase chromatographic peak splitting was observed when a mAb was exposed to elevated temperatures. Multiple LC-MS based methods were applied to identify the reason for peak splitting. The approach involved the use of complementary HPLC columns, multiple enzymatic digestions and different MS/MS ion dissociation methods. In addition, mAb potency was measured by enzyme-linked immunosorbent assay (ELISA). The split peaks had identical masses, and the root cause of the peak splitting was identified as isomerization of an aspartic acid located in the complementarity-determining region (CDR) of the light chain. And the early eluting and late eluting peaks were collected and performed enzymatic digestion to confirm the isoAsp enrichment in the early eluting peak. In addition, decreased potency was observed in the same heat-stressed sample, and the increased isoAsp levels in the CDR correlate well with a decrease of potency. Liquid chromatography-mass spectrometry (LC-MS) has been utilized extensively to assess PQAs of biological therapeutics. In this study, a generalizable LC-MS-based approach was developed to enable identification and quantitation of the isoAsp-containing peptides.

Bioavailability and daily requirement of vitamin B12 in adult humans: an observational study of its colonic absorption and daily excretion as measured by [13C]-cyanocobalamin kinetics

BackgroundClinical and biochemical vitamin B12 (B12) deficiency is lower than anticipated in vegetarians. Extraileal absorption, such as from the colon, as well as reduced daily excretion, may be adaptive mechanisms to maintain B12 homeostasis with marginal intakes. ObjectiveTo measure the absorption of B12 from the small and large intestine, and its daily rate of excretion from the body, using a [13C]-cyanocobalamin tracer. MethodsOral B12 bioavailability was measured over 12 h after administration of [13C]-cyanocobalamin tracer (2.5 μg) in normal participants. The colonic B12 bioavailability was evaluated by direct instillation of [13C]-cyanocobalamin (5 μg) into the ascending colon. Bioavailability was calculated from 2-compartmental modeling of the tracer appearance in plasma. The excretion rate of B12 was measured from [13C]-cyanocobalamin elimination from the body over 4 wk after oral dosing (5 μg). ResultsThe oral B12 bioavailability (n = 11) was 63% ± 10% measured over 12 h. A late absorption peak, accounting for 12% of the absorption, was observed after an average lag time of 8.7 h from dosing. The colonic B12 bioavailability (n = 10) was 7% ± 5% over 4 h. The daily B12 excretion rate (n = 4) was 0.7 ± 0.2 μg/d. The minimum daily requirement of B12 in these participants was derived at 1 μg /d. ConclusionsB12 is absorbed in the human colon. This observation confirms the potential contribution of the colon in daily B12 nutriture, and along with a possible lower requirement, could explain the absence of clinical deficiency in populations with marginal B12 intakes. Trial Registration NumberThis study was registered in Clinical Trials Registry of India (CTRI) with the registration number CTRI/2018/04/012957, available from https://ctri.nic.in/Clinicaltrials/showallp.php?mid1=49319&EncHid=&userName=029108.

Pineal Gland Hormone Melatonin Inhibits Migration of Hematopoietic Stem/Progenitor Cells (HSPCs) by Downregulating Nlrp3 Inflammasome and Upregulating Heme Oxygenase-1 (HO-1) Activity.

Hematopoietic stem progenitor cells (HSPCs) follow the diurnal circulation rhythm in peripheral blood (PB) with nadir during late night and peak at early morning hours. The level of these cells in PB correlates with activation of innate immunity pathways, including complement cascade (ComC) that drives activation of Nlrp3 inflammasome. To support this, mice both in defective ComC activation as well as Nlrp3 inflammasome do not show typical changes in the diurnal level of circulating HSPCs. Migration of HSPCs is also impaired at the intracellular level by the anti-inflammatory enzyme heme oxygenase-1 (HO-1) which is an inhibitor of Nlrp3 inflammasome. It is also well known that circadian rhythm mediates PB level of melatonin released from the pineal gland. Since trafficking of HSPCs is driven by innate immunity-induced sterile inflammation and melatonin has an anti-inflammatory effect, we hypothesized that melatonin could negatively impact the release of HSPCs from BM into PB by inhibiting Nlrp3 inflammasome activation. We provide anevidence that melatonin being a ''sleep regulating pineal hormone'' directly inhibits migration of HSPCs both in vitro migration assays and in vivo during pharmacological mobilization. This correlated with inhibition of cholesterol synthesis required for a proper membrane lipid raft (MLRs) formation and an increase in expression of HO-1-an inhibitor of Nlrp3 inflammasome. Since melatonin is a commonly used drug, this should be considered while preparing a patient for the procedure of HSPCs mobilization. More importantly, our studies shed more mechanistic light on a role of melatonin in the diurnal circulation of HSPCs.

Echocardiographic multiparameter assessment for patients with heart failure with preserved ejection fraction and atrial fibrillation.

We aimed to assess the echocardiographic parameters of cardiac structure and function in patients with heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF). Thirty-seven HFpEF patients with AF were selected, while 38 patients with simple HFpEF in the same period were selected as controls. Three-dimensional speckle-tracking echocardiography was performed on both groups and the parameters were compared. The early diastolic longitudinal peak strain rates [early diastolic longitudinal strain rate (LSRE), early diastolic circumferential strain rate (CSRE), early diastolic radial strain rate (RSRE) and early diastolic rotational strain rate (RotRE)], late diastolic longitudinal peak strain rates (LSRA, CSRA, RSRA and RotRA) and untwisting parameters [untwisting rate during isovolumic relaxation time (UTRIVR) and early peak untwisting rate (UTRE)] were all negatively correlated with the ratio of early diastolic transmitral velocity to early diastolic mitral annular velocity ( E/E') (p < 0.01). The cardiac event-free survival rate of the simple HFpEF group (92.11%) was significantly higher than that of the HFpEF + AF group (81.08%) (p < 0.0001). UTRIVR had a more significant correlation with E/E' ratio than the other indicators and could serve as a sensitive indicator for evaluating the diastolic function of patients with HFpEF + AF.