Weak Aggregation Research Articles

Flavonoids from Millettia nitida var. hirsutissima with their anticoagulative activities and inhibitory effects on NO production

Two new compounds, (2R)-7,3'-dihydroxy-6,4'-methoxyflavan (1) and (3R)-7,4'-dihydroxy-2'-methoxyisoflavan (2), along with 12 known flavonoids (3-14), were isolated from the vine stems of Millettia nitida var. hirsutissima. The structures of the isolated compounds were elucidated based on spectroscopic analyses and comparison of literature data. All of the isolates were evaluated for their effects on in-vitro anticoagulative assay and on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated RAW264.7 macrophages. As a result, all compounds showed weak antiplatelet aggregation activities and compounds 4, 5, 7, 8 and 9 demonstrated antithrombin activity with a good dose-effect relationship from 5 to 100 μg mL⁻¹ in rabbit plasma. Compounds 8, 9, 10 and 14 exhibited inhibitory effects on LPS-induced NO production in RAW264.7 macrophages with IC₅₀ values of 4.79 ± 0.20, 8.23 ± 0.35, 5.23 ± 0.11 and 6.30 ± 0.30 μg mL⁻¹, respectively.

DNA binding and nuclease activity of a water-soluble sulfonated manganese(III) corrole

The interaction of a water-soluble sulfonated Mn(III) corrole Mn(tpfc)(SO3Na)2 [tpfc = 5,10,15-tris(pentafluorophenyl)corrole] with calf thymus DNA (ct-DNA) has been studied by spectroscopic methods, and the nuclease activity of this complex has also been examined by agarose gel electrophoresis. Mn(tpfc)(SO3Na)2 exhibits weak aggregation tendency in buffer solution and can bind to ct-DNA via an outside binding mode with a binding constant of 1.25 × 104 M−1. The observed increase in Stern–Volmer quenching constant with increasing temperature indicates that the competition of the manganese corrole and ethidium bromide with ct-DNA is a dynamic process. Moreover, the manganese corrole displays good chemical nuclease activity in the presence of hydrogen peroxide via oxidative cleavage of DNA.

Abnormal Whole Blood Thrombi in Humans with Inherited Platelet Receptor Defects

To delineate the critical features of platelets required for formation and stability of thrombi, thromboelastography and platelet aggregation measurements were employed on whole blood of normal patients and of those with Bernard-Soulier Syndrome (BSS) and Glanzmann’s Thrombasthenia (GT). We found that separation of platelet activation, as assessed by platelet aggregation, from that needed to form viscoelastic stable whole blood thrombi, occurred. In normal human blood, ristocetin and collagen aggregated platelets, but did not induce strong viscoelastic thrombi. However, ADP, arachidonic acid, thrombin, and protease-activated-receptor-1 and -4 agonists, stimulated both processes. During this study, we identified the genetic basis of a very rare double heterozygous GP1b deficiency in a BSS patient, along with a new homozygous GP1b inactivating mutation in another BSS patient. In BSS whole blood, ADP responsiveness, as measured by thrombus strength, was diminished, while ADP-induced platelet aggregation was normal. Further, the platelets of 3 additional GT patients showed very weak whole blood platelet aggregation toward the above agonists and provided whole blood thrombi of very low viscoelastic strength. These results indicate that measurements of platelet counts and platelet aggregability do not necessarily correlate with generation of stable thrombi, a potentially significant feature in patient clinical outcomes.

CHARACTERISTICS AND LAND POTENTIAL FOR VEGETABLE DEVELOPMENT IN TEMANGGUNG DISTRICT, CENTRAL JAVA

Vegetables are mostly grown in mountainous areas with an altitude >400 m a.s.l., such as Temanggung, Central Java. The steep slope farming considers very little environmental suitability and sustainability. This study was conducted in 2004, covering a total area of 87,223 ha. Soil samples were analyzed for soil texture, pH, C, N, P, K, CEC, exchangeable cations, and base saturation. Soil characteristics data were used for land suitability evaluation for vegetables crops using the Automated Land Evaluation System (ALES) program. The results showed that 36,992 ha (42.4%) of the area is located in the elevation of 400-700 m a.s.l. and about 46,786 ha (53.6%) with elevation >700 m a.s.l. The district is dominated by volcanic parent materials (83.31%), deriving Andisols with shallow ( 15% covering 40,600 ha (46.55%) area. The district’s annual rainfall ranges from 2,375-3,054 mm with 7-9 wet months (rainfall >200 mm) and <3 dry months (rainfall <100 mm). Land suitability analysis indicated that <15% of the total area is very suitable (S1) for vegetables. The majority of the land is moderately suitable (S2) and marginally suitable (S3) for asparagus, garlic, green beans, chili, long beans, potatoes, cabbage and tomatoes, with limiting factors of steep slope, coarse to stony texture, high nutrient retention and low water availability. Other limiting factors include high rainfall, weak aggregates of the Andisols, and steep slopes, causing a high erosion hazard, unless proper soil conservation measures are implemented. Selection and implementation of locally adaptable conservation techniques and P nutrient management are important for sustainable vegetable farming in this area.

Coherent and Incoherent Interactions between Cofacial Π-Conjugated Oligomer Dimers in Macrocycle Templates

The interactions between two π-conjugated oligomers templated in molecular scaffolds are revealed as a function of separation and orientation, providing models of intermolecular interactions in bulk organic semiconductor materials. For a variety of dimer geometries (acyclic and macrocyclic) of the same model oligomer, no change in fluorescence spectra, fluorescence dynamics, or low-temperature single-molecule emission characteristics is observed. A small red-shift and slowing of fluorescence in the most closely spaced macrocyclic dimer structure is thought to arise both due to an intramolecular solvatochromic shift as well as from weak intramolecular aggregate formation. No corresponding effect is observed in bulk films of the acyclic model oligomer, implying the absence of intermolecular aggregate or excimer formation due to random relative dipole orientations. The largest effect of intramolecular geometry of the model dimer structures is seen in transient fluorescence depolarization, where an open ring geometry leads to rapid depolarization, compared to the corresponding macrocycle, due to the presence of a range of molecular transition dipole moment orientations. Self-assembled monolayers of the molecules on HOPG investigated by scanning-tunneling microscopy further illustrate the conformational variability of the open dimers in contrast to the fixed conformation of the closed dimers.

Validated SNPs for eGFR and their associations with albuminuria

Albuminuria and reduced glomerular filtration rate are manifestations of chronic kidney disease (CKD) that predict end-stage renal disease, acute kidney injury, cardiovascular disease and death. We hypothesized that SNPs identified in association with the estimated glomerular filtration rate (eGFR) would also be associated with albuminuria. Within the CKDGen Consortium cohort (n= 31 580, European ancestry), we tested 16 eGFR-associated SNPs for association with the urinary albumin-to-creatinine ratio (UACR) and albuminuria [UACR >25 mg/g (women); 17 mg/g (men)]. In parallel, within the CARe Renal Consortium (n= 5569, African ancestry), we tested seven eGFR-associated SNPs for association with the UACR. We used a Bonferroni-corrected P-value of 0.003 (0.05/16) in CKDGen and 0.007 (0.05/7) in CARe. We also assessed whether the 16 eGFR SNPs were associated with the UACR in aggregate using a beta-weighted genotype score. In the CKDGen Consortium, the minor A allele of rs17319721 in the SHROOM3 gene, known to be associated with a lower eGFR, was associated with lower ln(UACR) levels (beta = -0.034, P-value = 0.0002). No additional eGFR-associated SNPs met the Bonferroni-corrected P-value threshold of 0.003 for either UACR or albuminuria. In the CARe Renal Consortium, there were no associations between SNPs and UACR with a P< 0.007. Although we found the genotype score to be associated with albuminuria (P= 0.0006), this result was driven almost entirely by the known SHROOM3 variant, rs17319721. Removal of rs17319721 resulted in a P-value 0.03, indicating a weak residual aggregate signal. No alleles, previously demonstrated to be associated with a lower eGFR, were associated with the UACR or albuminuria, suggesting that there may be distinct genetic components for these traits.

Dead zones as safe havens for planetesimals: influence of disc mass and external magnetic field

(Abridged) Planetesimals embedded in a protoplanetary disc are stirred by gravitational torques exerted by density fluctuations in the surrounding turbulence. In particular, planetesimals in a disc supporting fully developed magneto-rotational turbulence are readily excited to velocity dispersions above the threshold for catastrophic disruption, halting planet formation. We aim to examine the stirring of planetesimals lying instead in a magnetically-decoupled midplane dead zone, stirred only by spiral density waves propagating out of the disc's magnetically-coupled turbulent surface layers. We extend previous studies to include a wider range of disc models, and explore the effects of varying the disc column density and external magnetic field strength. [...] The strength of the stirring is found to be independent of the gas surface density, which is contrary to the increase with disc mass expected from a simple linear wave picture. The discrepancy arises from the shearing out of density waves as they propagate into the dead zone, resulting in density structures near the midplane that exert weaker stochastic torques on average. We provide a simple analytic fit to our numerically obtained torque amplitudes that accounts for this effect. The stirring on the other hand depends sensitively on the net vertical magnetic flux, up to a saturation level above which magnetic forces dominate in the turbulent layers. For the majority of our models, the equilibrium planetesimal velocity dispersions lie between the thresholds for disrupting strong and weak aggregates, suggesting that collision outcomes will depend on material properties. However, discs with relatively weak magnetic fields yield reduced stirring, and their dead zones provide safe-havens even for the weakest planetesimals against collisional destruction.

Evaluation of platelet aggregometry in dogs using the Multiplate platelet analyzer: impact of anticoagulant choice and assay duration

To investigate the performance of the Multiplate platelet function analyzer with regards to: (1) the use of 3 different anticoagulants (ie, citrate, hirudin, and heparin) and (2) the evaluation of optimal assay time. Prospective observational in vitro study. University veterinary teaching hospital. Twenty clinically healthy dogs and 3 ill dogs. None. A total of 184 analyses were performed with duplicate measurements in each test cell and results are reported as mean of the 2 measurements. Analyses were performed on blood samples from 20 dogs collected in citrate, hirudin, or heparin. A total of 4 analyses were performed on every blood sample using adenosine diphosphate, collagen, and arachidonic acid as agonists as well as a control with 0.9% sodium chloride (buffer). Aggregation in hirudin samples was significantly increased compared with heparin at all analysis times except at 6 minutes when using ADP as agonist; however, hirudin samples also demonstrated significant aggregation in the buffer control, compared to both citrate and heparin. Citrated samples yielded significantly lower aggregation compared with both hirudin- and heparin-stabilized samples at 6 and 12 minutes when ADP and collagen were used as agonists, and at most analysis times with arachidonic acid. The assay performed best at shorter analyses times, whereas longer analyses times yielded larger variation in data. There was a good aggregation response and acceptable analytical variation in both heparin- and hirudin-anticoagulated samples with all tested agonist at the concentrations recommended by the manufacturer. The results suggest that heparin may be superior as anticoagulant for Multiplate analyses in dogs and that short analyses times are preferable. Spontaneous platelet autoaggregation in hirudin samples warrants careful evaluation of results using this anticoagulant, especially at longer test times. The use of citrate is discouraged for Multiplate analyses in dogs due to a weak aggregation response.

Solute‐Induced Microstructural Transition from Weak Aggregates towards a Curved Film of Surface‐Active Extractants

Solute‐Induced Microstructural Transition from Weak Aggregates towards a Curved Film of Surface‐Active Extractants

Analysis on the Relationship and its Dynamics Between Rural Settlements and Linear Features Using Gis and Rs

Abstract The relationship between spatial patterns of rural settlements and environment and its dynamics were analyzed in Daxing District, Beijing in the recent 20 years using landsat TM images. Results showed that too much of land in total was used for the rural settlements in the study area with a rapid growth, and it had a great potential for land intensive utilization; the rural settlements were rather small, with weak aggregation and high random expanse in spatial distribution; highways, rivers and channels were important factors that affected the spatial distribution of rural settlements, while railways and expressways exhibited little influence. Accordingly, to guarantee the unified and balanced development of rural and urban construction, planning for villages and towns are required, and considering the convenience of road transportation and water use is an important principle for the selection of central towns and the systematic planning of rural settlements; on the other hand, areas along the hi...

Problems of particle aggregation in ceramics

Abstract Three types of problem are presented to illustrate the thesis that small interatomic forces between ceramic particles have a major influence on the aggregates formed during processing and on the final ceramic product microstructure and strength. The first is a theoretical problem of ceramic particle aggregation to define the weak interatomic forces between spheres. The second concerns the better processing that can be applied to dispersed particles to deliver improved ceramic properties by adding polymer to ceramic dispersions to reduce particle attractions which lead to aggregation. The last is the application of polymer extrusion to make improved ceramic fuel cells which can start up in a short time to provide auxiliary power to new applications. The conclusion is that understanding and controlling weak aggregation forces between particles during powder processing can lead to better ceramic microstructures and products.

On the dynamics of planetesimals embedded in turbulent protoplanetary discs with dead zones

(abridged) Accretion in protoplanetary discs is thought to be driven by [...] turbulence via the magnetorotational instability (MRI). Recent work has shown that a planetesimal swarm embedded in a fully turbulent disc is subject to strong excitation of the velocity dispersion, leading to collisional destruction of bodies with radii R_p < 100 km. Significant diffusion of planetesimal semimajor axes also arises, leading to large-scale spreading of the planetesimal population throughout the inner regions of the protoplanetary disc, in apparent contradiction of constraints provided by the distribution of asteroids within the asteroid belt. In this paper, we examine the dynamics of planetesimals embedded in vertically stratified turbulent discs, with and without dead zones. Our main aims are to examine the turbulent excitation of the velocity dispersion, and the radial diffusion, of planetesimals in these discs. We employ three dimensional MHD simulations [...], along with an equilibrium chemistry model [...] We find that planetesimals in fully turbulent discs develop large random velocities that will lead to collisional destruction/erosion for bodies with sizes below 100 km, and undergo radial diffusion on a scale \sim 2.5 au over a 5 Myr disc life time. But planetesimals in a dead zone experience a much reduced excitation of their random velocities, and equilibrium velocity dispersions lie between the disruption thresholds for weak and strong aggregates for sizes R_p < 100 km. We also find that radial diffusion occurs over a much reduced length scale \sim 0.25 au over the disc life time, this being consistent with solar system constraints. We conclude that planetesimal growth via mutual collisions between smaller bodies cannot occur in a fully turbulent disc. By contrast, a dead zone may provide a safe haven in which km-sized planetesimals can avoid mutual destruction through collisions.

Effect of recycled coarse aggregate on concrete compressive strength

The effect of recycled coarse aggregate on concrete compressive strength was investigated based on the concrete skeleton theory. For this purpose, 30 mix proportions of concrete with target cube compressive strength ranging from 20 to 60 MPa were cast with normal coarse aggregate and recycled coarse aggregate from different strength parent concretes. Results of 28-d test show that the strength of different types of recycled aggregate affects the concrete strength obviously. The coarse aggregate added to mortar matrix plays a skeleton role and improves its compressive strength. The skeleton effect of coarse aggregate increases with the increasing strength of coarse aggregate, and normal coarse aggregate plays the highest, whereas the lowest concrete strength occurs when using the weak recycled coarse aggregate. There is a linear relationship between the concrete strength and the corresponding mortar matrix strength. Coarse aggregate skeleton formula is established, and values from experimental tests match the derived expressions.

Electrochemical cell with solid oxide electrolyte and oxygen pump thereof

The paper presents the scientific basis and technical implementation of a method for obtaining oxygen by extraction from air using an electrochemical cell based on a solid oxide cell (SOC) with anion-conducting solid electrolyte. A nanopowder of a weak aggregate of the YSZ solid electrolyte and LSM fine powder was used to manufacture SOC. The electrolyte-electrode SOC structure was formed as a tube by joint pressing of functional layers and the further co-sintering at the temperature of 1200°C. The characteristics of an electrochemical cell of the oxygen pump based on a thin-wall tube of the YSZ supporting electrolyte (150 μm) with symmetrical electrodes based on LSM (∼20 μm) are studied. A prototype of a compact oxygen generator (oxygen pump) is developed and manufactured with an electrochemical part based on three serially connected SOCs. The connection is implemented in the form of metallic couplings of the Crofer 22 APU steel. The method of reaction magnetron sputtering was used to protect current leads from corrosion by applying a coating based on a MnxCo3 − xO4 spinel. The efficiency of a demonstration prototype at 800°C was 9 l/h at the power consumption of 50 W. The current density through SOC was 1.1 A/cm2. The prototype was designed to contain no noble metal components. It is shown that the engineering approach applied allows manufacturing effective nanostructural SOCs and devices on their basis.

Distribution of phosphorus in size fractions of sandy soils with different fertilization histories

AbstractA major challenge in sustainable crop management is to ensure adequate P supply for crops, while minimizing losses of P that could negatively impact water quality. The objective of the present study was to investigate the effects of long‐term applications of different levels of mineral fertilizers and farmyard manure on (1) the availability of P, (2) the relationship between soil C, N, and P, and (3) the distribution of inorganic and organic P in size fractions obtained by wet sieving. Soil samples were taken from the top 20 cm of a long‐term (29 y) fertilization trial on a sandy Cambisol near Darmstadt, SW Germany. Plant‐available P, determined with the CAL method, was little affected by fertilization treatment (p &lt; 0.05) and was low to optimal. The concentration of inorganic and organic P extracted with a NaOH‐EDTA solution (PNaOH‐EDTA) averaged about 350 mg (kg dry soil)–1, with 42% being in the organic form (Po). Manure application tended to increase soil C, N, and Po concentrations by 8%, 9%, and 5.6%, respectively. Across all treatments, the C : N : Po ratio was 100 : 9.5 : 2 and was not significantly affected by the fertilization treatments. Aggregate formation was weak due to the low clay and organic‐matter content of the soil, and the fractions &gt; 53 μm consisted predominantly of sand grains. The different fertilization treatments had little effect on the distribution of size fractions and their C, N, and P contents. In the fractions &gt; 53 μm, PNaOH‐EDTA ranged between 200 and 300 mg kg–1, while it reached 1260 mg kg–1 in the fraction &lt; 53 μm. Less than one third of PNaOH‐EDTA was present as Po in the fractions &gt; 53 μm, while Po accounted for 70% of PNaOH‐EDTA in the smallest fraction (&lt; 53 μm). Therefore, 16% and 28% of PNaOH‐EDTA and Po, respectively, were associated with the smallest fraction, even though this fraction accounted for &lt; 5% of the soil mass. Therefore, runoff may cause higher P losses than the soil P content suggests in this sandy soil with a weak aggregate formation. Overall, the results indicate that manure and mineral fertilizer had similar effects on soil P fractions.

Grazing changes topography-controlled topsoil properties and their interaction on different spatial scales in a semi-arid grassland of Inner Mongolia, P.R. China

Semiarid steppe ecosystems account for large terrestrial areas and are considered as large carbon (C) sinks. However, fundamental information on topsoil sensitivity to grazing is lacking across different spatial scales including the effects of topography. Our interdisciplinary approach considering soil chemical, physical, and vegetation properties included investigations on pit scale (square-metre scale), plot scale (hectare scale), and the scale of a landscape section (several hectares). Five different sites, representing a grazing intensity gradient, ranging from a long-term grazing exclosure to a heavily grazed site were used. On the pit scale, data about aggregate size distribution, quantity of different soil organic carbon (SOC) pools, SOC mineralisation, hydraulic conductivity and shear strength was available for topsoil samples from representative soil profiles. Spatial variability of topographical parameters, topsoil texture, bulk density, SOC, water repellency, and vegetation cover was analysed on the basis of regular, orthogonal grids in differently grazed treatments by using two different grid sizes on the plot scale and landscape section. On the pit scale, intensive grazing clearly decreased soil aggregation and the amount of fresh, litter-like particulate organic matter (POM). The weak aggregation in combination with animal trampling led to an enhanced mineralisation of SOC, higher topsoil bulk densities, lower infiltration rates, and subsequently to a higher risk of soil erosion. On the plot scale, the effects of soil structure disruption due to grazing are enhanced by the degradation of vegetation patches and resulted in a texture-controlled wettability of the soil surface. In contrast, topsoils of grazing exclosures were characterised by advantageous mechanical topsoil characteristics and SOC-controlled wettability due to higher POM contents. A combined geostatistical and General Linear Model approach identified topography as the fundamental factor creating the spatial distribution of texture fractions and related soil parameters on the scale of a landscape section. Grazing strongly interfered with the topography-controlled particle relocation processes in the landscape and showed strongest effects on the aboveground biomass production and biomass-related soil properties like SOC stocks. We conclude that interdisciplinary multi-scale analyses are essential (i) to differentiate between topography- and grazing-controlled spatial patterns of topsoil and vegetation properties, and (ii) to identify the main grazing-sensitive processes on small scales that are interacting with the spatial distribution and relocation processes on larger scales.

Aggregation of molecules in liquid pyridine and its solutions: Raman spectra and quantum-chemical calculations

In solutions of pyridine–propan-2-ol the ring vibration band of the hydrogen-bonded aggregates (H-aggregates) is shifted towards greater frequencies and changes its position with the change of pyridine concentration. The application of the mixture diluting method in a large amount of a neutral solvent (triple mixture) allows one to “resolve” the aggregates band structure. The observed doublet structure of the band is connected with the presence of two types of H-aggregates in liquid mixture. Quantum-chemical calculations confirm the high-frequency shift of 992 cm − 1 band of pyridine in the formation of aggregates with propan-2-ol. Similar calculations for isolated aggregates of pyridine–methyl alcohol show that several types of aggregates are possible including closed three-molecular H-aggregates of pyridine molecule with two molecules of methyl alcohol. Calculations show also that the pyridine molecules can form among themselves a weak dimer aggregate with two intermolecular hydrogen bonds.

Photosensitized isomerization of olefin with benzophenone-conjugated amphiphilic graft copolymers

Two kinds of amphiphilic graft copolymers, PAA- g-P(MMA- co-BP) and P(AA- co-BP)- g-PMMA, consisting of polar poly(acrylic acid) (PAA), less polar poly(methyl methacrylate) (PMMA), and benzophenone (BP) photosensitizing units, have been synthesized. These polymers, when used as a photosensitizer for isomerization of trans- β-methylstyrene, show a sensitization activity controlled by solvents. In benzene and chloroform, P(AA- co-BP)- g-PMMA forms a micelle structure consisting of aggregated P(AA- co-BP) core with dissolved PMMA units at the outer sphere. This suppresses a triplet energy transfer (TET) from the excited state BP units to olefin and, hence, shows lower sensitization activity than a bulk sensitizer (4-methoxybenzophenone: MBP). In methanol, both polymers form a weak aggregate of less polar PMMA units containing dissolved PAA units. The internal cavity of the aggregate is less polar and stabilizes the excited state BP units. This accelerates a TET from the excited state BP units to olefin and shows higher sensitization activity than MBP.

Platelet aggregation in severe sepsis

Severe sepsis and multiple organ distress syndrome remain a diagnostic and therapeutic challenge for intensive therapy. Platelet activating factor forms a bridge between inflammation and clot formation. Our study surveys the effect of severe sepsis on platelet function and focuses on spontaneous aggregation in severely ill patients. Daily arterial blood samples were collected from 45 patients (average age of 60.7 ± 13) for five consecutive days following admission and 30 healthy controls. Platelet aggregation was measured using adrenaline (ADR), adenosine diphosphate (ADP), collagen (COL) and normal saline (SAL). Clinical status was observed using Multiple Organ Dysfunction Score (MODS) and Sequential Organ Failure Assessment (SOFA) score systems. Inducible aggregation deteriorated in septic patients in all 5 days with ADR, ADP and COL (P < 0.05) while SAL aggregation was increased during intensive care. Low platelet patients showed weak inducible aggregation with ADP throughout, with ADR on the 2nd, 3rd, 4th and 5th days and with COL on the 1st, 2nd and 3rd days. SAL aggregation showed no significance. No significant difference was seen between platelet functions comparing survivors and non-survivors. In the spontaneous aggregative group, platelet count was insignificantly higher, while procalcitonin levels were lower in 1st, 3rd and 4th days and no significant difference was observed in lactate levels. We demonstrated the presence of spontaneous platelet activity while overall inducible platelet aggregation is significantly deteriorated in septic patients. There were significant differences in inducible aggregation between normal and low platelet count groups. Inducible platelet function had no predictive value in the outcome.

Transmission Electron Microscopy Observation of Corrosion Behaviors of Platinized Carbon Blacks under Thermal and Electrochemical Conditions

Carbon blacks such as Vulcan XC-72 are widely used to support platinum (Pt) or Pt alloy catalysts in proton exchange membrane fuel cells. Despite their widespread use, carbon blacks are susceptible to corrosion during fuel cell operations. In this work, the corrosion behaviors of platinized Vulcan XC-72 nanoparticles under thermal and electrochemical conditions were monitored by transmission electron microscopy (TEM). The thermal corrosion experiment was carried out in a gas-cell TEM, which allows for a direct observation of the thermal oxidation behavior of the nanoparticles. The electrochemical corrosion experiment was performed outside of the TEM by loading the nanoparticles on a TEM grid and then electrochemically corroding them step by step followed by taking TEM images from exactly the same nanoparticles after each step. This work revealed four types of structural changes: (i) total removal of structurally weak aggregates, (ii) breakdown of aggregates via neck-breaking, (iii) center-hollowed primary particles caused by an inside-out corrosion starting from the center to outer region, and (iv) gradual decrease in the size of primary particles caused by a uniform removal of material from the surface. These structural changes took place in sequence or simultaneously depending on the competition of carbon corrosion dynamical processes. The results obtained from this work provide insight on carbon corrosion and its effects on fuel cells’ long-term performance and durability.