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Intratumoral Biosynthesis of Gold Nanoclusters by Pancreatic Cancer to Overcome Delivery Barriers to Radiosensitization

Date: 2024
Authors: Schwartz-Duval, AS;Mackeyev, Y;Mahmud, I;Lorenzi, PL;Gagea, M;Krishnan, S;Sokolov, KV;
References: ACS nano 18 1865-1881
Keywords/Products: Concentric;Concentric nebulizer;ICP;ICP-MS;Meinhard;
Nanoparticle delivery to solid tumors is a prime challenge in nanomedicine. Here, we approach this challenge through the lens of biogeochemistry, the field that studies the flow of chemical elements within ecosystems as manipulated by living cellular organisms and their environments. We leverage biogeochemistry concepts related to gold cycling against pancreatic cancer, considering mammalian organisms as drivers for gold nanoparticle biosynthesis. Sequestration of gold nanoparticles within tumors has been demonstrated as an effective strategy to enhance radiotherapy; however, the desmoplasia of pancreatic cancer impedes nanoparticle delivery. Our strategy overcomes this barrier by applying an atomic-scale agent, ionic gold, for intratumoral gold nanoparticle biosynthesis. Our comprehensive studies showed the cancer-specific synthesis of gold nanoparticles from externally delivered gold ions in vitro and in a murine pancreatic cancer model in vivo; a substantial colocalization of gold nanoparticles (GNPs) with cancer cell nuclei in vitro and in vivo; a strong radiosensitization effect by the intracellularly synthesized GNPs; a uniform distribution of in situ synthesized GNPs throughout the tumor volume; a nearly 40-day total suppression of tumor growth in animal models of pancreatic cancer treated with a combination of gold ions and radiation that was also associated with a significantly higher median survival versus radiation alone (235 vs 102 days, respectively).

Effect of liquid aerosol temperature on the detection performance of LIBS for analysis of phosphorus element in water

Date: 2024
Authors: Yang, X;Wang, X;Li, D;Zhang, X;Li, K;Ren, H;Zhou, Z;Qin, Z;Zheng, X;
References: Journal of Analytical Atomic Spectrometry 39 433-438
Keywords/Products: Aerosol;Concentric;Concentric nebulizer;Meinhard;
A simple and convenient method has been developed to improve the LIBS detection performance of a liquid aerosol by adjusting the liquid aerosol temperature.

Reply to “Comment on Comparison of direct and indirect measures of transport efficiency in single particle inductively coupled plasma mass spectrometry” by H. Goenaga-Infante

Date: 2024
Authors: Murphy, K;Montoro Bustos, A;Yu, L;Johnson, M;Winchester, M;
References: Spectrochimica Acta Part B: Atomic Spectroscopy ~ 106902
Keywords/Products: Concentric;Concentric nebulizer;ICP;ICP-MS;Meinhard;
This paper provides a rebuttal to the comments on our original research article entitled “Comparison of Direct and Indirect Measures of Transport Efficiency in Single Particle ICP-MS” recently

Effect of feeding meal of yellow and lesser mealworm and defatted black soldier fly larvae on growth performance and gut health of weaned piglets

Date: 2024
Authors: Malla, N;Roos, N;Van der Heide, M;Nørgaard, J;
References: Animal Feed Science and Technology 309 115917
Keywords/Products: Meinhard;
Black soldier fly larvae (BSFL), lesser mealworm (LMW) and yellow mealworm (YMW) are suggested as a sustainable novel protein source which could improve growth and gastrointestinal function and health of weaned piglets. The objective of this study was to investigate the effects of BSFL, LMW and YMW in diets for weaned piglets on growth performance and gut health-related parameters. A total of 96 crossbred [(Landrace × Yorkshire) × Duroc] male piglets weaned at 28 days of age with an average weight of 6.6 ± 0.5?kg were used. For 2 weeks, piglets were fed a control diet (CTRL) with 14% enzyme-treated soybean meal or diets containing 2.66% enzyme-treated soybean meal and dried meal of defatted BSFL larvae, LMW and YMW at 8.35, 9, and 7.66% respectively. In each diet, 24 piglets were randomly allocated in individual pens. For all the growth performance parameters, no differences were observed among dietary treatments. All the treatments showed similar values of Immunoglobulin A (IgA). The concentration of D-lactate was not affected by treatments. Piglets fed LMW and YMW diets demonstrated a lower concentration of diamine oxidase (DAO; 321 and 309?ng/ml, respectively) than in the CTRL diet (382?ng/ml, P

The Boumaadine Fe-Mn-Pb-Cu (± Au) ore deposit (Jbel Skindis, eastern High Atlas, Morocco): New insights from geological, hydrothermal alteration and geochemical investigations

Date: 2024
Authors: Tobi, A;Essalhi, M;Barbanson, L;Zouggarh, A;Benaissi, L;El Azmi, D;Majidi, R;
References: Journal of African Earth Sciences 211 105169
Keywords/Products: Glass Nebulizer;Meinhard;
Petrographic, structural and geochemical analysis combined with SEM and XRD were performed on the Boumaadine Fe-Mn-Pb-Cu (±Au) mineralization of Jbel Skindis in the eastern High Atlas, (Morocco). The results indicate a polyphasic process of mineralization, which produced orebodies with distinct features and different chemical conditions formation. The earliest mineralization formed replacement and disseminated Fe-Mn-Pb orebodies under oxidizing conditions, with a mineral assemblage composed of coronadite, plumboferrite, cesarolite, specularite and calcite, in association with a large-scale hydrothermal alteration consisting essentially of Fe-Mn minerals, i.e., ferroan dolomite, hematite, jacobsite and limonite. The second event was formed under reducing conditions that generate some veins filled mainly by sulfides (galena, with minor pyrite and chalcopyrite), in addition of calcite and dolomite. The mineralization is hosted in Lower Liassic dolostones and is linked to the structural evolution of the study area. Fractures related to the displacement of the Boumaadine fault seem to control the disposition and the localization of the alteration and the mineralization: (i) the Fe-Mn-Pb oxides are related to a NE-SW conjugate fault system generated during the first phase of deformation, with a horizontal principal stress striking NNW-SSE, and (ii) the sulfide mineralization occurs mainly as filling conjugate fractures of two preferentially directions striking N80-90 and N150-165 with a slight dip (15-40°) to the NE. These latter were caused by a dextral movement along the Boumaadine fault, generated during the late phase of deformation with a NW-SE bearing horizontal principal stress. The deep-seated Boumaadine fault has acted as pathways for the rising fluids, and supports the origin of lead and other metals from the Paleozoic basement. The Triassic evaporitic sequence along the Boumaadine fault has also contributed to the chemical composition of the fluid, and represents the potential source of both the salinity and sulfur. The oxide-sulfide mineralogical assemblage and its associated alteration emphasize a polyphasic hydrothermal activity with distinct physicochemical conditions; an iron-manganese rich, and highly oxidizing brine is considered to be responsible for the Fe-Mn alteration and for the deposit of the oxide assemblage. Furthermore, a mixing of the oxidizing fluid with a meteoric reducing fluid could have resulted in the sulfide-rich ore.

Effects of short-term exercise and endurance training on skeletal muscle mitochondria damage induced by particular matter, atmospherically relevant artificial PM2.5

Date: 2024
Authors: Liu, W;Wang, Z;Gu, Y;So, HS;Kook, SH;Park, Y;Kim, SH;
References: Frontiers in public health 12 1302175
Keywords/Products: Meinhard;TQ-50-C0.5;
This study aimed to investigate the potential of short-term aerobic exercise to mitigate skeletal muscle mitochondrial damage following ambient PM2.5 exposure, and how 12?weeks of endurance training can enhance aerobic fitness to protect against such damage.Twenty-four male C57BL/6?J mice were split into sedentary (SED, n?=?12) and endurance training (ETR, n?=?12) groups. The ETR group underwent 12?weeks of training (10-15?m/min, 60?min/day, 4 times/week), confirmed by an Endurance Exercise Capacity (EEC) test. Post-initial training, the SED group was further divided into SSED (SED and sedentary, n?=?6) and SPE (SED and PM2.5?+?Exercise, n?=?6). Similarly, the ETR group was divided into EEX (ETR and Exercise, n?=?6) and EPE (ETR and PM2.5?+?Exercise, n?=?6). These groups underwent 1?week of atmospherically relevant artificial PM2.5 exposure and treadmill running (3 times/week). Following treatments, an EEC test was conducted, and mice were sacrificed for blood and skeletal muscle extraction. Blood samples were analyzed for oxidative stress indicators, while skeletal muscles were assessed for mitochondrial oxidative metabolism, antioxidant capacity, and mitochondrial damage using western blot and transmission electron microscopy (TEM).After 12?weeks of endurance training, the EEC significantly increased (p <?0.000) in the ETR group compared to the SED group. Following a one-week comparison among the four groups with atmospherically relevant artificial PM2.5 exposure and exercise treatment post-endurance training, the EEX group showed improvements in EEC, oxidative metabolism, mitochondrial dynamics, and antioxidant functions. Conversely, these factors decreased in the EPE group compared to the EEX. Additionally, within the SPE group, exercise effects were evident in HK2, LDH, SOD2, and GPX4, while no impact of short-term exercise was observed in all other factors. TEM images revealed no evidence of mitochondrial damage in both the SED and EEX groups, while the majority of mitochondria were damaged in the SPE group. The EPE group also exhibited damaged mitochondria, although significantly less than the SPE group.Atmospherically relevant artificial PM2.5 exposure can elevate oxidative stress, potentially disrupting the benefits of short-term endurance exercise and leading to mitochondrial damage. Nonetheless, increased aerobic fitness through endurance training can mitigate PM2.5-induced mitochondrial damage.

Copper Speciation in Wine Growing-Drain Waters: Mobilization, Transport, and Environmental Diffusion

Date: 2024
Authors: De Carsalade du Pont, V;Ben Azzouz, A;El Hadri, H;Chéry, P;Lespes, G;
References: Environments 11 19
Keywords/Products: Agilent;ICP;ICP-MS;Meinhard;
Copper (Cu) has been used to treat vines for a long time, which has led to its accumulation in vineyard soils. In the present work, the mobilization of copper from these soils and its transport, and diffusion outside the plots by drain water were investigated. For this, the distribution of copper between the dissolved and colloidal phases, and within the colloidal phase, of these waters was determined using an investigation strategy based on the coupling between a size separation technique, asymmetric flow field-flow fractionation, and several detectors. First, the total copper concentrations in water from different drains were monitored over a period of 2 years: Cu was mainly found in the fraction of < 450 nm. Then, the distribution of copper on the size continuum was more closely studied in water from one of the drains, sampled over a winter period. Between 45 and 75% of Cu was found in the 2-450 nm colloidal fraction. The <450 nm colloidal phase of the drain waters was found to be mainly composed of humic acids (~15 to 60 mg L?1) and clay-rich particles (~100 to 650 mg (Al) L?1). These particles also contained (hydr)oxides of iron and manganese. The concentrations of Fe and Mn were approximately 100 to 200 times lower than those of Al. The majority of humic acids had an apparent molar mass of ? 10 kDa. They were distributed along the size continuum: (i) in a population with an average size of ~20 nm, probably consisting of supramolecular entities, and (ii) associated with clay-rich particles with a size of ~120-200 nm. Copper was found to be complexed with humic acids and associated with clays via clay-humic complexes. Copper mobilization from the soil to the water and its transport to the drain water appeared governed by the soil humidity level and the rainfall.

Modern instrumentation and practical application of flame atomic emission spectrometry

Date: 2024
Authors: Zauer, E;
References: Chimica Techno Acta 11 ~
Keywords/Products: Concentric;Meinhard;
The modern instrumentation for flame atomic emission spectrometry (FAES) is overviewed: the main technical (composition of the fuel gas used, dispersing element, number of analytical channels, reference channel, detecting element, sampling method) and analytical (determined elements, range of determined concentrations, limits and the accuracy of their determination, the duration of a single measurement, the equired amount of the analyzed sample) characteristics of flame photometers for industrial and clinical use as well as spectrophotometers currently made by various manufacturers such as Sherwood Scientific Ltd., BWB Technologies UK Ltd., Labtron Equipment Ltd., Labnics Equipment Ltd. and JENWAY Ltd (UK); A.KRÜSS Optronic (Germany); Cole Parmer Instrument Company and Labfon Equipment Inc. (USA); Inesa Analytical Instrument Co., Ltd (China); OJSC Zagorsk Optical and Mechanical Plant, Unico-SIS LLC and VMK-Optoelectronics LLC (Russia); Manti Lab Solutions, Labtronics, Systonic, Globe Instruments, Electronics India, Lasany (India). The main areas of application of FAES are presented - bioenergy, agriculture (analysis of plants, soil extracts and fertilizers), mineral raw materials (geology), clinical medicine and pharmaceuticals, food industry, environmental control (analysis of drinking, technical and waste water), nuclear energy, metallurgy and chemical industry, as well as some features and problems associated with the preparation of samples for analysis by the FAES method. The review includes references to works on the practical application of FAES, published mainly from 1998 to 2023. 

The radioactive contamination of ground and surface water near a uranium mine in Malawi

Date: 2024
Authors: Majawa, L;Jegede, O;Tshivhase, V;Chobeka, B;Mokgele, T;
References: Brazilian Journal of Radiation Sciences 12 e2341
Keywords/Products: Meinhard;
Ground and surface water in the uranium mining area of Kayelekera in Malawi was assessed for concentration levels of radioactive metals. Potential health risks associated with the intake of these metals in drinking water from various sources were also estimated. Surface, groundwater and mine discharge water samples were collected and analysed for radio elemental concentration using inductively coupled plasma mass spectrometry analytical technique. The results indicated a high concentration of 238U in water samples from lower Sere river. The activity concentrations of 238U, 232Th and 40K were however below WHO recommended limit. Health risk assessment using average committed effective dose were below the global average. Excess lifetime cancer risk values with an average of  for borehole water was calculated and found to be below the global average. Radiologically, the water quality of Kayelekera area post uranium mining activities has not been compromised, however close monitoring and treating of drinking water is recommended

Large- and Small-Animal Studies of Safety, Pharmacokinetics (PK), and Biodistribution of Inflammasome-Targeting Nanoligomer in the Brain and Other Target Organs

Date: 2024
Authors: Risen, S;Kusick, B;Sharma, S;Gilberto, V;Brindley, S;Aguilar, M;Brown, J;McGrath, S;Chatterjee, A;Moreno, J;Nagpal, P;
References: bioRxiv ~ ~
Keywords/Products: ICP;ICP-MS;Meinhard;sample introduction;
Immune malfunction or misrecognition of healthy cells and tissue, termed autoimmune disease, is implicated in more than 80 disease conditions and multiple other secondary pathologies. While pan-immunosuppressive therapies like steroids offer some relief for systemic inflammation for some organs, many patients never achieve remission and such drugs do not cross the blood-brain barrier making them ineffective for tackling neuroinflammation. Especially in the brain, unintended activation of microglia and astrocytes is hypothesized to be directly or indirectly responsible for Multiple Sclerosis (MS), Amyotrophic Lateral Sclerosis (ALS), Parkinson’s Disease (PD), and Alzheimer’s Disease (AD). Recent studies have also shown that targeting inflammasome and specific immune targets can be beneficial for these diseases. Further, our previous studies have shown targeting NF-?B and NLRP3 through brain penetrant Nanoligomer cocktail SB_NI_112 (abbreviated to NI112) can be therapeutic for several neurodegenerative diseases. Here we show safety-toxicity studies, followed by pharmacokinetics (PK) and biodistribution in small- (mice) and large-animal (dog) studies of this inflammasome-targeting Nanoligomer cocktail NI 112. We conducted studies using four different routes of administration: intravenous (IV), subcutaneous (SQ), intraperitoneal (IP), and intranasal (IN), and identified the drug concentration over time using inductively coupled plasma mass spectrometry (ICP-MS) in the blood serum, the brain (including different brain regions), and other target organs like liver, kidney, and colon. Our results indicate the Nanoligomer cocktail has a strong safety profile, and shows high biodistribution (F ?0.98) and delivery across multiple routes of administration. Further analysis showed high brain bioavailability with a ratio of NI112 in brain tissue to blood serum ?30%. Our model accurately shows dose scaling, translation between different routes of administration, and interspecies scaling. These results provide an excellent platform for human clinical translation and predicting therapeutic dosage between different routes of administration.

Large- and Small-Animal Studies of Safety, Pharmacokinetics, and Biodistribution of Inflammasome-Targeting Nanoligomer in the Brain and Other Target Organs

Date: 2024
Authors: Risen, S;Kusick, B;Sharma, S;Gilberto, V;Brindley, S;Aguilar, M;Brown, J;McGrath, S;Chatterjee, A;Moreno, J;Nagpal, P;
References: ACS Pharmacology & Translational Science ~ ~
Keywords/Products: Meinhard;sample introduction;
Immune malfunction or misrecognition of healthy cells and tissue, termed autoimmune disease, is implicated in more than 80 disease conditions and multiple other secondary pathologies. While pan-immunosuppressive therapies like steroids can offer limited relief for systemic inflammation for some organs, many patients never achieve remission, and such drugs do not cross the blood-brain barrier, making them ineffective for tackling neuroinflammation. Especially in the brain, unintended activation of microglia and astrocytes is hypothesized to be directly or indirectly responsible for multiple sclerosis, amyotrophic lateral sclerosis, Parkinson’s disease, and Alzheimer’s disease. Recent studies have also shown that targeting inflammasomes and specific immune targets can be beneficial for these diseases. Furthermore, our previous studies have shown targeting NF-?B and NLRP3 through brain penetrant Nanoligomer cocktail SB_NI_112 (abbreviated as NI112) can be therapeutic for several neurodegenerative diseases. Here, we show safety-toxicity studies, followed by pharmacokinetics and biodistribution in small- (mice) and large-animal (dog) studies of this inflammasome-targeting Nanoligomer cocktail NI112. We conducted studies using four different routes of administration: intravenous, subcutaneous, intraperitoneal, and intranasal, and identified the drug concentration over time using inductively coupled plasma mass spectrometry in the blood serum, the brain (including different brain regions), and other target organs such as liver, kidney, and colon. Our results indicate that the Nanoligomer cocktail has a strong safety profile and shows high biodistribution (F ? 0.98) and delivery across multiple routes of administration. Further analysis showed high brain bioavailability with a ratio of NI112 in brain tissue to blood serum of ?30%. Our model accurately shows dose scaling, translation between different routes of administration, and interspecies scaling. These results provide an excellent platform for human clinical translation and prediction of therapeutic dosage between different routes of administration.

Differential impact of diesel exhaust particles on glutamatergic and dopaminergic neurons in Caenorhabditis elegans: A neurodegenerative perspective

Date: 2024
Authors: Chatterjee, N;González-Durruthy, M;Costa, M;Ribeiro, A;Vilas-Boas, V;Vilasboas-Campos, D;Maciel, P;Alfaro-Moreno, E;
References: Environment International ~ 108597
Keywords/Products: Concentric;Concentric nebulizer;Meinhard;
The growing body of evidence links exposure to particulate matter pollutants with an increased risk of neurodegenerative diseases. In the present study, we investigated whether diesel exhaust particles can induce neurobehavioral alterations associated with neurodegenerative effects on glutamatergic and dopaminergic neurons in Caenorhabditis elegans. Exposure to DEP at concentrations of 0.167?µg/cm2 and 1.67?µg/cm2 resulted in significant developmental delays and altered locomotion behaviour. These effects were accompanied by discernible alterations in the expressions of antioxidant genes sod-3 and gst-4 observed in transgenic strains. Behaviour analysis demonstrated a significant reduction in average speed (p?

Sample preparation - A crucial step to distinguish metallic and ionic platinum forms and their mobility in soil

Date: 2024
Authors: Kowalska, J;Bortka, K;Sadowska, M;Ki?ska, K;Krasnod?bska-Ostr?ga, B;
References: Chemosphere 352 141331
Keywords/Products: Meinhard;NexION;
The study is focused on one of the technology-critical elements (TCEs), Pt in the context of distinguishing ionic from metallic forms and assessing sorption capacity of soil. Solid-liquid extraction, cross-comparison of the results of two determination techniques and two decomposition methods enable quantitative determination of the ionic form and, indirectly, NPs in soil and plants. Information about ionic form is obtained after sample digestion with conc. HNO3 and AdSV determination, and total Pt content is determined after digestion using mixture of conc. HNO3 and conc. HCl. The recovery of Pt was in the range 99-110 % for both forms. The mobility (0.43 mol L-1 HAc) of Pt-NPs and Pt (II) was below 1 % even in the presence of citrates (after 2 month incubation). The long-term sorption study indicated that Pt retention (both forms) in the organic soil is related to formation of organic complexes, and the equilibrium is achieved after 2 days. When the soil is enriched in Fe2O3, stronger sorption is observed up to 2 days for both Pt forms (the mobility is 9-14 pp. lower), to finally achieve similar sorption as without modification, reaching 89/90 % for incubation with DI water, and 81/85 % with citrates. The addition of biocarbon/biochar does not play an important role in immobilization of Pt (II) and Pt-NPs.

Early-stage growth and elemental composition patterns of Brassica napus L. in response to Cd-Zn contamination

Date: 2024
Authors: T?zsér, D;Idehen, DO;Osazuwa, JD;Sule, JE;Ragyák, ÁZ;Sajtos, Z;Magura, T;
References: Chemosphere 351 141235
Keywords/Products: Agilent;ICP;Meinhard;POINT;
Soil contamination caused by the presence of Cd and the excess amount of Zn is a widespread concern in agricultural areas, posing significant risks to the growth and development of crops. In this paper, the early-stage development and metal (Cd and Zn) accumulation potential of rapeseed (Brassica napus L.) grown under different metal application schemes were assessed by determining radicle and hypocotyl length and the micro- and macro elemental composition of plantlets after 24, 72, and 120 h. The results indicated that the single and co-application of Cd and Zn significantly reduced the radicle and hypocotyl lengths. Accumulation intensity for Cd and Zn was affected by Cd and the combination of Cd and Zn in the solution, respectively. In addition, both metals significantly influenced the tissue Mn and had a minor effect on Cu and Fe concentrations. Both Cd and Zn significantly affected macro element concentrations by decreasing tissue Ca and influencing K and Mg concentrations in a dose- and exposure time-dependent manner. These findings specify the short-term and support the long-term use of rapeseed in remediation processes. However, interactions of metals are crucial in determining the concentration patterns in tissues, which deserves more attention in future investigations.

Exploitation of Luminescent Lanthanide Nanoparticles for a Sensitivity-Enhanced ELISA Detection Method

Date: 2024
Authors: Kassir, AA;Cheignon, C;Charbonnière, LJ;
References: Analytical chemistry 96 2107-2116
Keywords/Products: ICP;ICP-AES;Meinhard;Varian;
A new detection method based on the photoluminescence properties of dye-sensitized lanthanide nanoparticles (Ln NPs) was developed for enzyme-linked immunosorbent assays (ELISAs). In this method, the horseradish peroxidase (HRP) enzyme catalyzes the oxidation of phenol derivatives in the presence of hydrogen peroxide, providing dimers that are able to interact with the Ln NP surface and to efficiently photosensitize the Ln ions. Due to the very long emission lifetime of Ln, the time-gated detection of Ln NP luminescence allows the elimination of background noise due to the biological environment. After a comparison of the enzyme-catalyzed oxidation of various phenol derivatives, methyl 4-hydroxyphenyl acetate (MHPA) was selected as the most promising substrate, as the highest Ln emission intensity was observed following its HRP-catalyzed oxidation. After a meticulous optimization of the conditions of both the enzymatic reaction and the Ln sensitization (buffer, pH, concentration of the reactants, NP type, etc.), this new detection method was successfully implemented in a commercial insulin ELISA kit as a proof-of-concept, with an increased sensitivity compared to the commercial detection method.

Gravimetric, morphological, and chemical characterization of fine and ultrafine particulate matter inside fire stations

Date: 2024
Authors: Sousa, G;Teixeira, J;Azevedo, R;Almeida, A;Delerue-Matos, C;Morais, S;Wang, X;Rodrigues, F;Freitas, M;Oliveira, M;
References: Building and Environment ~ 111403
Keywords/Products: Concentric;Concentric nebulizer;iCAP;ICP;ICP-MS;Meinhard;Thermo;
Poor air quality inside buildings has direct implications for human health. The activity of firefighters causes cancer and promotes the development/aggravation of cardio-respiratory diseases. The indoor air quality inside fire stations remains poorly characterized. This work assesses firefighters’ daily exposure to fine (PM2.5, PM156nm) and ultrafine (PM50.4nm, PM30.8nm) particulate matter (PM) inside three microenvironments of fire stations, and, for the first time, characterizes the morphology and elemental content of collected PM. Fine PM fractions were predominant in all microenvironments. Fine and ultrafine PM concentrations were increased in the personal protective equipment (PPE) storage room than in the common area and garage [11.84-103.5 ?g/m3 versus 18.67-51.89 ?g/m3 and 22.57-70.69 ?g/m3; p > 0.05 and 4.78-46.02 ?g/m3 versus 3.03-40.99 ?g/m3 and 5.55-23.30 ?g/m3; p > 0.05]; values were below the guideline proposed for occupational exposure to respirable dust (5.0 mg/m3). The morphological analysis revealed the presence of organic matter, microorganisms, crystals, minerals, metals, and other unidentified substances in fine/ultrafine PM. Exposure to total PM-bound metals was increased in the garage comparatively to the common area and the PPE storage room (2765.0-46586.0 pg/m3 versus 2414.2-4568.6 pg/m3; p > 0.5). Cu, Zn, and Cr were the predominant PM-bound metals while Sb, Cd, and Tl were the less abundant. Exposure to PM-bound possible/probable carcinogenic metals (Ni, Cd, Sb, and Pb) accounted for 7.81-10.72% and 0.342-13.07% of fine and ultrafine PM, respectively. The data generated can support regulatory agencies in proposing air quality guidelines that promote occupational safety and health.

Hybrid ultrasound and photoacoustic contrast agent designs combining metal phthalocyanines and PBCA microbubbles

Date: 2024
Authors: Barmin, RA;Moosavifar, M;Zhang, R;Rütten, S;Thoröe-Boveleth, S;Rama, E;Ojha, T;Kiessling, F;Lammers, T;Pallares, RM;
References: Journal of materials chemistry. B 12 2511-2522
Keywords/Products: Meinhard;
Photoacoustic (PA) imaging is an emerging diagnostic technology that combines the penetration depth of ultrasound (US) imaging and the contrast resolution of optical imaging. Although PA imaging can visualize several endogenous chromophores to obtain clinically-relevant information, multiple applications require the administration of external contrast agents. Metal phthalocyanines have strong PA properties and chemical stability, but their extreme hydrophobicity requires their encapsulation in delivery systems for biomedical applications. Hence, we developed hybrid US/PA contrast agents by encapsulating metal phthalocyanines in poly(butyl cyanoacrylate) microbubbles (PBCA MB), which display acoustic response and ability to efficiently load hydrophobic drugs. Six different metal chromophores were loaded in PBCA MB, showing greater encapsulation efficiency with higher chromophore hydrophobicity. Notably, while the US response of the MB was unaffected by the loading of the chromophores, the PA characteristics varied greatly. Among the different formulations, MB loaded with zinc and cobalt naphthalocyanines showed the strongest PA contrast, as a result of high encapsulation efficiencies and tunable optical properties. The strong US and PA contrast signals of the formulations were preserved in biological environment, as demonstrated by in vitro imaging in serum and whole blood, and ex vivo imaging in deceased mice. Taken together, these findings highlight the advantages of combining highly hydrophobic PA contrast agents and polymeric MB for the development of contrast agents for hybrid US/PA imaging, where different types of information (structural, functional, or potentially molecular) can be acquired by combining both imaging modalities.

Effect of l-serine and magnesium ions on the functional properties of human phosphoserine phosphatase and its pathogenetic variants

Date: 2024
Authors: Marchesani, F;Comani, VB;Bruno, S;Mozzarelli, A;Carcelli, M;Pollegioni, L;Caldinelli, L;Peracchi, A;Campanini, B;
References: Biochimica et biophysica acta. Molecular basis of disease 1870 167034
Keywords/Products: Meinhard;
L-Ser supply in the central nervous system of mammals mostly relies on its endogenous biosynthesis by the phosphorylated pathway (PP). Defects in any of the three enzymes operating in the pathway result in a group of neurometabolic diseases collectively known as serine deficiency disorders (SDDs). Phosphoserine phosphatase (PSP) catalyzes the last, irreversible step of the PP. Here we investigated in detail the role of physiological modulators of human PSP activity and the properties of three natural PSP variants (A35T, D32N and M52T) associated with SDDs. Our results, partially contradicting previous reports, indicate that: i. PSP is almost fully saturated with Mg2+ under physiological conditions and fluctuations in Mg2+ and Ca2+ concentrations are unlikely to play a modulatory role on PSP activity; ii. Inhibition by L-Ser, albeit at play on the isolated PSP, does not exert any effect on the flux through the PP unless the enzyme activity is severely impaired by inactivating substitutions; iii. The so-far poorly investigated A35T substitution was the most detrimental, with a 50-fold reduction in catalytic efficiency, and a reduction in thermal stability (as well as an increase in the IC50 for L-Ser). The M52T substitution had similar, but milder effects, while the D32N variant behaved like the wild-type enzyme. iv. Predictions of the structural effects of the A35T and M52T substitutions with ColabFold suggest that they might affect the structure of the flexible helix-loop region.

Microwave-sustained inductively coupled atmospheric-pressure plasma (MICAP) for the elemental analysis of complex matrix samples

Date: 2024
Authors: Serrano, R;Grindlay, G;Gras, L;Mora, J;
References: Talanta 271 125666
Keywords/Products: ICP;ICP-OES;Meinhard;Type A;
Microwave induced plasma optical emission spectrometry (MIP-OES) has gained widespread attention in the last few years for trace elemental analysis. Among the new generation of MIPs it is worth to mention the microwave-sustained inductively coupled atmospheric-pressure plasma (MICAP) for which previous works have shown similar detection capabilities to those afforded by ICP-OES. Nevertheless, this instrument has not been applied yet to complex matrix sample analysis. Therefore, the goal of this work is to evaluate MICAP-OES performance (e.g., analytical figures of merit, matrix effects, etc.) for elemental analysis of samples of different nature (e.g., environmental, food and polymers). To this end, both spectral and non-spectral interferences were investigated for 19 elements (Ag, Al, As, B, Ca, Cd, Co, Cr, Cu, Fe, Ga, In, Mg, Mn, Ni, Pb, Sr, Tl, Zn) in the presence of inorganic acid, organic and saline solutions and compared to a 5 % w w-1 HNO3 solution. Unlike previous MIPs, experimental data showed that the optimum nebulizer gas flow rate for a given emission wavelength was mostly independent of matrix characteristics. Regarding matrix effects, this device was highly robust operating both inorganic acid and organic matrices. Interestingly, when operating saline matrices, changes on emission signal by easily ionizable elements were less significant than those early reported by alternative MIP cavities. Moreover, due to MICAP spectrometer design employed allows real-time simultaneous analysis, Rh, Pd, Sc and Y were suitable internal standards to minimize non-spectral interferences. Finally, MICAP-OES can be successfully applied to the elemental analysis of different complex matrix samples (i.e., CRM-DW1 Drinking water; BCR-146 Sewage sludge industrial; BCR-185 Bovine liver; BCR-278R Mussel tissue; NIST-1549 Non-fat milk powder; ERM-EC681k Polyethylene (high level) and BCR-483 Sewage sludge amended soil).

Exposome and Metabolome Analysis of Sugarcane Workers Reveals Predictors of Kidney Injury

Date: 2024
Authors: Stem, A;Brindley, S;Rogers, K;Salih, A;Roncal-Jimenez, C;Johnson, R;Newman, L;Butler-Dawson, J;Krisher, L;Brown, J;
References: Kidney International Reports ~ ~
Keywords/Products: Meinhard;
Introduction Sugarcane workers are exposed to potentially hazardous agrochemicals, including pesticides, heavy metals, and silica. Such occupational exposures present health risks and have been implicated in a high rate of kidney disease seen in these workers. Methods To investigate potential biomarkers and mechanisms that could explain chronic kidney disease (CKD) among this worker population, paired urine samples were collected from sugarcane cutters at the beginning and end of a harvest season in Guatemala. Workers were then separated into 2 groups, namely those with or without kidney function decline (KFD) across the harvest season. Urine samples from these 2 groups underwent elemental analysis and untargeted metabolomics. Results Urine profiles demonstrated increases in silicon, certain pesticides, and phosphorus levels in all workers, whereas heavy metals remained low. The KFD group had a reduction in estimated glomerular filtration rate (eGFR) across the harvest season; however, kidney injury marker 1 did not significantly change. Cross-harvest metabolomic analysis found trends of fatty acid accumulation, perturbed amino acid metabolism, presence of pesticides, and other known signs of impaired kidney function. Conclusion Silica and certain pesticides were significantly elevated in the urine of sugarcane workers with or without KFD. Future work should determine whether long-term occupational exposure to silica and pesticides across multiple seasons contributes to CKD in these workers. Overall, these results confirmed that multiple exposures are occurring in sugarcane workers and may provide insight into early warning signs of kidney injury and may help explain the increased incidence of CKD among agricultural workers.