Large Concentration Differences Research Articles

Coimmunocapture and Electrochemical Quantitation of Total and Phosphorylated Amyloid-β40 Monomers.

Phosphorylated proteins play important roles in the pathogenesis of Alzheimer's disease (AD). The most abundant constituent in AD's brain deposit is the amyloid-β40 peptide (Aβ40). Based on it, the degree of phosphorylated Aβ40 in body fluids (e.g., cerebrospinal fluid, CSF), which is defined by the ratio of phosphorylated Aβ40 to total Aβ40 (pAβ40/tAβ40), is anticipated to be an index for early diagnosis of AD. The major challenge in pAβ40/tAβ40 detection is the large concentration difference between two Aβ40 forms in the real samples, which usually requires multichannel equipment and complicated detection process. In this paper, we revealed the unexpected close affinities of the anti-Aβ40 antibody to Aβ40 (40.2 nM-1) and to pAβ40 (42.3 nM-1). Based on it, a convenient coimmunocapture and electrochemical quantitation of tAβ40 and pAβ40 was achieved on an anti-Aβ40 antibody immobilized Au electrode (anti-Aβ40/Au). Once Aβ40 and pAβ40 were synchronously captured on the anti-Aβ40/Au electrode, the tAβ40 levels in CSF samples were quantified with electrochemical impedance spectroscopy. With the signal amplification from Cd2+/Ti4+-functionalized titanium phosphate nanospheres (Cd2+/Ti4+@TiP) which was selective conjugated to pAβ40, concentrations of low abundant pAβ40 as low as 1 fM were readily measured by square wave voltammetry. Our results reveal that despite the concentrations of tAβ40 and pAβ40 fluctuate in each individual case, the concentration ratios of pAβ40/tAβ40 in CSF samples from AD patients are significant larger than those from healthy donors. It demonstrates that the degree of phosphorylated Aβ40 is hopeful to be an effective index for evaluating the AD progress and improving the accuracy of clinic AD diagnosis.

Elemental analysis of Brazilian coffee with ion beam techniques: From ground coffee to the final beverage

Brazilian coffee is well known worldwide due to its quality and richness in taste. The aim of the present study is to provide the elemental characterization of Brazilian coffee along different stages of the drip brewing process. To that end, samples from roasted ground coffee, spent coffee, paper filters and the final beverage were analyzed with one single ion beam technique, namely particle-induced X-ray emission (PIXE). In total, over 140 samples from 8 different Brazilian brands of ground coffee were analyzed. Large differences in some elemental concentrations were observed among different brands and among different batches of a single brand, which leads to high variances in the data. Concerning the beverage preparation, the analysis of the spent coffee shows that the transfer ratio from the ground coffee to the beverage differs for each element. Our results indicate that potassium and chlorine have the highest transfer ratio. Moreover, the concentration of rubidium is relatively high in drinking coffee. Finally, there is no influence of the elemental composition of paper filter in the preparation of drinking coffee.

Vertical distributions of black carbon aerosols over rural areas of the Yangtze River Delta in winter

Based on a field campaign in Shouxian, a rural site on the Yangtze River Delta, China, from December 14, 2016 to January 4, 2017, the vertical profiles of black carbon (BC) and planetary boundary layer (PBL) structures were studied. In total, 58 vertical profiles were obtained, including of the PM2.5, BC mass concentration (mBC) and relevant meteorological parameters. Four profile types were categorized: I: uniform vertical distributions (38%), II: higher values at lower altitudes (29%), III: bimodal distributions with high values near the ground and at higher altitudes (17%), and IV: unimodal distributions with high values at higher altitudes (11%). A further analysis confirmed that all types were mainly influenced by the PBL diurnal evolution and local emissions, while types III and IV were strongly associated with the temperature inversions at low altitudes. The diurnal variations of the BC vertical profiles mainly followed the evolution of the PBL. In the early morning, the average mBC within the PBL (MBL, BC) increased significantly, reaching the highest level in the diurnal cycles, i.e., approximately 13.0 μg m−3. The pollutants were confined to a thin layer <0.2 km above the ground, which contributed to the smoke produced by local residential biomass burning. Around noon, the accumulated BC in the layer was diluted as a result of the development of the PBL. The height of the PBL (HPBL) reached its maximum in the afternoon, with an average of 0.65 km, while MBL, BC dropped to its minimum, with an average of 7.8 μg m−3. As evening approached, the BC produced by local residential biomass burning gradually accumulated near the ground and linearly declined along the standardized height (HS) within the nocturnal boundary layer (NBL). There were large differences in the BC concentration within and above the PBL both in the daytime and at night.

Spinal myoclonus following neuraxial anesthesia: a literature review.

Spinal myoclonus (SM) is a rare neurologic movement disorder following neuraxial anesthesia (NA). SM following NA (SM-NA) has insufficient clinical information and its pathogenesis remains to be elucidated. The aim of this review article was to summarize the past cases and consider SM-NA pathophysiology. Based on our PubMed search, it was revealed that SM-NA develops within several hours after neuraxial local anesthetic (LA) administration and resolves in a day without leaving neurologic compilations. It occurs primarily in the lower extremities, but can sometimes spread upward and affect the upper extremities and trunk. Although statistical adjustments are indispensable, analysis of the previous cases provided important facts that seem to be related with the mechanism of SM-NA. The frequently used LAs for spinal anesthesia were hyperbaric. SM-NA occurrence was more frequent in women. After initiation of spinal anesthesia, intrathecal hyperbaric LA distributes cephalad. In the LA elimination process, the large concentration differences in intrathecal LA may induce the partially functioning spinal neurons, resulting in myoclonus generation. The morphological features of the lumbar spine in women can predispose to a higher LA concentration difference. SM-NA is an unpredictable and rare neural complication following NA and should be confirmed by basic experiments and large-scale researches.

Photocontrolled self-assembly of azobenzene nanocontainers in water: light-triggered uptake and release of lipophilic molecules.

An easy to synthesize azobenzene based amphiphile spontaneously self-assembles into monodisperse nanoaggregates in water. The large difference in the critical aggregation concentration between the E and Z stereoisomeric forms enables photocontrol of its aggregation state over a wide concentration range: light-triggered release and uptake of lipophilic molecules is achieved in aqueous solution.

Impact of the Great East Japan Earthquake on Polycyclic Aromatic Hydrocarbons in Sediments on the Coast of Matsushima Bay, Northern Japan

We investigated the concentration, composition, and distribution of polycyclic aromatic hydrocarbons (PAHs) in sediments from the Matsushima Bay area (Miyagi Prefecture, Japan) in 2013—an area that experienced significant destruction in the Great East Japan Earthquake and tsunamis of March 2011—using gas chromatography–mass spectrometry (GC-MS). Their PAH concentration and composition were compared with those of sediment samples collected in Tokyo Bay, which had not suffered similar impacts from the tsunamis. The PAH composition in the sediment collected in the Matsushima Bay area was dominated by phenanthrene, fluoranthene, and pyrene. These data suggest that the PAHs in the sediment are a result of combustion, and that oil pollution is now a negligible source of these pollutants in this area. The lowest total PAH concentration (84 μg/kg dry) was found in the outer area of the bay near Miyato-jima Island, an area permitting high-volume inflow and outflow from the open sea. The highest concentration (15,548 μg/kg dry) was at a former fishing harbor, located in the innermost area of the bay. The large difference in PAH concentrations between sites in Matsushima Bay may be attributable to particle redeposition after sediment disturbance by the tsunamis.

High-performance materials for effective sorptive removal of formaldehyde in air.

As formaldehyde (FA) is well-known for its carcinogenic potential, various techniques for its removal have been developed based on recovery (e.g., adsorption/absorption and condensation) or destructive treatment (e.g., incineration and thermal/ catalytic oxidation). Among them, adsorption has been one of the most preferable options due to its low price and simplicity. In this review, we summarize state-of-the-art knowledge about adsorption mechanisms with respect to its key controlling variables (e.g., surface chemical properties of adsorbent, temperature, and relative humidity) and adsorption performance of materials with particular emphasis on advanced materials (e.g., carbon nanotubes, metal-organic frameworks, graphene oxides, and porous organic polymers) and their modified forms in comparison with conventional sorbents (e.g., AC and zeolite). However, it is yet difficult to assess the adsorption capacity of each material on a parallel basis because adsorption experiments of each material were conducted under different conditions (e.g., large differences in the initial loading concentrations). The partition coefficient (PC) was employed for evaluating adsorption performance between different materials at an equivalent level to overcome the limitation based on adsorption capacity concept. For instance, among the list of the surveyed materials, the highest PC was recorded by γ-CD-MOF-K (31.2 mol kg-1 Pa-1). This study should offer valuable insights into the selection and development of outstanding materials for the sorptive removal of FA.

Evidence of canister contamination causing false positive detections in vapor intrusion investigation results

ABSTRACTWe have utilized the California GeoTracker database to evaluate field duplicate variability and the significance of sample contamination for groundwater and vapor samples collected from contaminated sites in California. Vapor duplicates are more variable than water duplicates with median percent difference in concentration of 25% compared to 7% for water samples. In addition, large differences in concentration were more common in vapor duplicates. For vapor analyte pairs, 20% of pairs had a percent difference in concentration of >300% while, for groundwater analyte pairs, only 3% had a percent difference of >300%. Contamination of samples during collection or analysis is also more significant for vapor samples. For water samples, sample contamination appears unlikely to result in false positive exceedances of drinking water standards; however, for vapor samples, sample contamination may result in false positive exceedances of indoor air screening values. For vapor samples, the use of reusable canisters and flow controllers is likely an important source of sample contamination.

Development of a novel unbalanced ammonia-water absorption-resorption heat pump cycle for space heating

Ammonia-water absorption-resorption heat pump (ARHP) is a promising technology for promoting efficient utilization of low-temperature thermal for space heating. This paper proposes a novel unbalanced ARHP cycle by replacing the condenser and evaporator in the conventional absorption heat pump (AHP) cycle with a high-pressure absorber and a low-pressure generator, respectively. The proposed cycle can work just depending on the concentration difference of ammonia-water solution under different pressure levels. A numerical model has been developed to investigate the feasible high-pressure/low-pressure (PH/PL) values to effect the thermodynamic cycle. The cycle's coefficient of performance (COP) under different PH/PL pair values and other given working conditions are studied. The maximum COP is 1.550 and the corresponding optimum PH/PL pair to effect the cycle is 1.40 MPa/0.38 MPa at a heat source temperature of 95 °C. When PH/PL pair value is 1.40/0.38 MPa, heat supply temperature of 44.5 °C and COP value of 1.331 can be obtained, which can basically meet the temperature demand of building floor heating. In addition, effects of different PH/PL pair values on solution circulation ratios and vapor discharge scopes of generators are discussed. It is concluded that the ideal PH/PL candidates yield large concentration difference between the inlet and outlet of generators and absorbers. Meanwhile, the solution circulation ratios of the two generators at ideal PH/PL pairs are acceptable values between 2.0 and 12.0. The cycle can work when the ambient temperature is above −7.5 °C and the driving heat source temperature is larger than 85 °C, which is potential in efficient utilization of commonly used stationary solar collectors for winter heating.

Energy drink exposures reported to Texas poison centers: Analysis of adverse incidents in relation to total sales, 2010–2014

The ill-defined term “energy drink” includes a disparate group of products (beverages, shots, concentrates, and workout powders) having large differences in caffeine content and concentration and intended use. Hence, inaccurate conclusions may be drawn when describing adverse events associated with “energy drinks”. The FDA is considering new regulation of these products but product specificity is needed to evaluate safety. To help address this, we queried Texas Poison Center Network data for single substance exposures to "energy drinks" from 2010 to 2014, then analyzed adverse events by product type. We specifically compared energy beverage exposures with sales data for the same time period to evaluate the safety profile of this category of energy drinks.Among 855 documented "energy drink" exposures, poison center-determined outcome severity revealed 291 with no/minimal effects, 417 judged nontoxic or minor/not followed, 64 moderate and 4 major effects, and no deaths. Serious complications included 2 seizures and 1 episode of ventricular tachycardia. Outcome severity by category for beverages: 11 moderate/1 major effects (none in children <17 years); shots: 19 moderate/2 major; non-liquids: 16 moderate/1 major; concentrates: 7 moderate; unknown: 10 moderate. Call incidence to poison centers for beverage type exposures was 0.58 (for moderate effects) and 0.053 (for major) per hundred million units sold.Small volume and concentrated products were associated with a greater number of adverse effects than beverage versions of "energy drinks".

Can anti-gravity running improve performance to the same degree as over-ground running?

ABSTRACTThis study examined the changes in running performance, maximal blood lactate concentrations and running kinematics between 85%BM anti-gravity (AG) running and normal over-ground (OG) running over an 8-week training period. Fifteen elite male developmental cricketers were assigned to either the AG or over-ground (CON) running group. The AG group (n = 7) ran twice a week on an AG treadmill and once per week over-ground. The CON group (n = 8) completed all sessions OG on grass. Both AG and OG training resulted in similar improvements in time trial and shuttle run performance. Maximal running performance showed moderate differences between the groups, however the AG condition resulted in less improvement. Large differences in maximal blood lactate concentrations existed with OG running resulting in greater improvements in blood lactate concentrations measured during maximal running. Moderate increases in stride length paired with moderate decreases in stride rate also resulted from AG training. The use of AG training to supplement regular OG training for performance should be used cautiously, as extended use over long periods of time could lead to altered stride mechanics and reduced blood lactate.

A novel enhanced diffusion sampler for collecting gaseous pollutants without air agitation

ABSTRACTA novel enhanced diffusion sampler for collecting gaseous phase polycyclic aromatic hydrocarbons (PAHs) without air agitation is proposed. The diffusion of target compounds into a sampling chamber is facilitated by continuously purging through a closed-loop flow to create a large concentration difference between the ambient air and the air in the sampling chamber. A glass-fiber filter-based prototype was developed. It was demonstrated that the device could collect gaseous PAHs at a much higher rate (1.6 ± 1.4 L/min) than regular passive samplers, while the ambient air is not agitated. The prototype was also tested in both the laboratory and field for characterizing the concentration gradients over a short distance from the soil surface. The sampler has potential to be applied in other similar situations to characterize the concentration profiles of other chemicals.

Differences in the distribution and optical properties of DOM between fresh and saline lakes in a semi-arid area of Northern China

In limnological environments, most organic carbon is present in the dissolved form. Dissolved organic carbon (DOC) is the main source of energy for microbial metabolism and biosynthesis, and also affects photosynthetic radiation level and the attenuation of ultraviolet irradiation to protect aquatic organisms. There are large differences in DOC concentration, source, and characteristics due to regional variations in water quality and basin characteristics. Reliable estimates of DOC and analysis of optical characteristics are crucial to understand the true role of lakes in the global carbon cycle. In this article, the distribution of DOC across 30 lakes in semi-arid areas of Northern China is reported. The data shows that saline lakes exhibited higher DOC concentrations than freshwater lakes, and the positive relationship between salinity and DOC was established (R2 = 0.42, p < 0.01, n = 196). The mean DOC concentration in eutrophic lakes was lower than in mesotrophic and oligotrophic lakes. Analysis of optical characteristics of CDOM indicated that saline lakes in this semi-arid regions contained abundant fulvic acid, and greater levels of autochthonous dissolved organic matter (DOM) with a lower molecular mass than fresh waters. The total suspended matter (TSM) is the main factor influencing on SUVA254 in both freshwater and saline lakes with a negative correlation. SUVA254 was negatively correlated with the salinity only in freshwater lakes, and with pH only in saline lakes. The result suggests that it was doubtful whether CDOM or SUVA254 alone can be a predictor of DOC concentration and other water quality parameters, especially in different types of lakes with different optical and physicochemical characteristics.

Electron donation characteristics and interplays of major volatile fatty acids from anaerobically fermented organic matters in bioelectrochemical systems

ABSTRACTAnaerobic fermentation liquid of waste organic matters (WOMs) is rich in volatile fatty acids (VFAs), which can be treated with bioelectrochemical systems for both electrical energy recovery and organics removal. In this work, four major VFAs in the fermented WOMs supernatant were selected to examine their electron donation characteristics for power output and their complicated interplays in microbial fuel cells (MFCs). Results indicated a priority sequence of acetate, propionate, n-butyrate and i-valerate when served as the sole electron donor for electricity generation. The MFC solely fed with acetate showed the highest coulombic efficiency and power density, and the longest period for electricity production. When two of the VFAs were added with equal proportion, both acids contributed positively to electricity generation, while the selective or competitive use of substrates by diverse microorganisms behaved as an antagonism effect to prolong the degradation time of each VFA. When acetate and propionate, the preferable substrates for electricity generation, were mixed in various proportions, their large concentration difference led to improved electrical performance but decreased organic removal rate.

Release of β-casomorphin-7 from bovine milk of different β-casein variants after ex vivo gastrointestinal digestion

The release of β-casomorphin-7 (BCM-7) in bovine milk with β-casein genetic variants A1, A2, F and I was assessed. An ex vivo gastrointestinal (GI) digestion model was applied and multiple reaction monitoring method for quantification of BCM-7 was set up using Triple-Q LC-ESI-MS specifically for the BCM-7 peptide. BCM-7 was released after digestion of milk of all variants, although with large differences in concentration between variants. Higher amounts of BCM-7 were found from milk samples of the A1 family (A1 and F) with 1.85–3.28 mg g−1 β-CN digested, whereas the A2 family (A2 and I) only released 0.01–0.06 mg g−1 β-CN digested. Compared with earlier findings on digestion of purified β-CN, this study showed larger differences in quantified BCM-7 between different milk types, potentially due to the different matrixes of the milk. However, all β-CN variants A1, A2, F and I released BCM-7 after GI digestion.

Claudin expression during early postnatal development of the murine cochlea

BackgroundClaudins are major components of tight junctions, which form the paracellular barrier between the cochlear luminal and abluminal fluid compartments that supports the large transepithelial voltage difference and the large concentration differences of K+, Na+ and Ca2+ needed for normal cochlear function. Claudins are a family of more than 20 subtypes, but our knowledge about expression and localization of each subtype in the cochlea is limited.ResultsWe examined by quantitative RT-PCR the expression of the mRNA of 24 claudin isoforms in mouse cochlea during postnatal development and localized the expression in separated fractions of the cochlea. Transcripts of 21 claudin isoforms were detected at all ages, while 3 isoforms (Cldn-16, − 17 and − 18) were not detected. Claudins that increased expression during development include Cldn-9, − 13, − 14, − 15, and -19v2, while Cldn-6 decreased. Those that do not change expression level during postnatal development include Cldn-1, − 2, − 3, − 4, − 5, − 7, − 8, −10v1, −10v2, − 11, − 12, −19v1, − 20, − 22, and − 23. Our investigation revealed unique localization of some claudins. In particular, Cldn-13 expression rapidly increases during early development and is mainly expressed in bone but only minimally in the lateral wall (including stria vascularis) and in the medial region (including the organ of Corti). No statistically significant changes in expression of Cldn-11, − 13, or − 14 were found in the cochlea of Slc26a4−/− mice compared to Slc26a4+/− mice.ConclusionsWe demonstrated developmental patterns of claudin isoform transcript expression in the murine cochlea. Most of the claudins were associated with stria vascularis and organ of Corti, tissue fractions rich in tight junctions. However, this study suggests a novel function of Cldn-13 in the cochlea, which may be linked to cochlear bone marrow maturation.

Survival of LA-MRSA in Dust from Swine Farms.

Dust is suspected to be an important factor in transmission of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) between pigs and pig farmers and their families. The aim of this study was to determine the rate of decay for Staphylococcus aureus and LA-MRSA in dust from swine farms. Electrostatic dust fall collectors (EDCs) were used for passive sampling of settling airborne dust in 11 stable sections from six swine farms. Extraction, plating, identification, and enumeration of cultivable S. aureus and LA-MRSA from the EDCs were performed after storage for 0–30 days postsampling. The survival of S. aureus was measured in 196 dust samples from all farms, and data were used to estimate the decay constant λ according to a model for exponential decay: N(t) = N0 × e−λt. The number of S. aureus colonies was up to 600-fold higher than the number of LA-MRSA colonies on MRSA selective agar. The data showed a good fit to the model (λ = 0.13, r2 = 0.86) even with a large difference in initial concentrations of S. aureus between stables. The loads of S. aureus and LA-MRSA in the dust were significantly reduced by storage time, and the half-life was 5 days for both S. aureus and LA-MRSA. In dust samples with high initial concentrations, LA-MRSA and S. aureus could still be cultivated 30 days after sampling. On all farms MRSA isolates belonged to the clonal complex (CC) 398, and at one farm some isolates also belonged to CC30. A screening for other Staphylococcus species in the farm dust revealed 13 different species numerically dominated by Staphylococcus equorum. Based on the exponential decay model, S. equorum had a half-life of 4 days. In conclusion, the presence of MRSA in airborne dust from five of six farms indicates that dust might be an important vehicle for transmission of LA-MRSA. LA-MRSA and S. aureus was found to survive well in farm dust with half-lives of 5 days, and dependent on the initial concentration they could be found in farm dust for weeks. The 99.9% die-off rate was 66 days for LA-MRSA. Thus, farm dust can pose an exposure risk for humans in the farm environment, but also when transported to other environments. On the other hand, the risk will decrease by time. These results provide important knowledge to diminish spread from farm environments to other environments on, e.g., tools or clothing, and in relation to cleaning of emptied LA-MRSA-positive stables.

DNA damage in Arctic seabirds: Baseline, sensitivity to a genotoxic stressor, and association with organohalogen contaminants

Environmental contaminants are found throughout Arctic marine ecosystems, and their presence in seabirds has been associated with toxicological responses. However, there are few studies of genotoxicity in Arctic avian wildlife. The purpose of the present study was to quantify deoxyribonucleic acid (DNA) damage in lymphocytes of selected seabird species and to examine whether accumulation of organohalogen contaminants (ΣOHCs) affects DNA damage. Blood was sampled from common eider (Somateria mollissima), black guillemot (Cepphus grylle), black-legged kittiwake (Rissa tridactyla), glaucous gull (Larus hyperboreus), arctic skua (Stercorarius parasiticus), and great skua (Stercorarius skua) in Kongsfjorden, Svalbard (Norway). Contaminant concentrations found in the 6 species differed, presumably because of foraging ecology and biomagnification. Despite large differences in contaminant concentrations, ranging from ΣOHCs 3.3 ng/g wet weight in the common eider to ΣOHCs 895 ng/g wet weight in the great skua, there was no strong difference among the species in baseline DNA damage or sensitivity to a genotoxic stressor (hydrogen peroxide). Baseline levels of DNA damage were low, with median values ranging from 1.7% in the common eider to 8.6% in the great skua. There were no associations between DNA damage and contaminants in the investigated species, suggesting that contaminant concentrations in Kongsfjorden are too low to evoke genotoxic effects, or possibly that lymphocytes are resistant to strand breakage. Clearly, genotoxicity is a topic for future studies of Arctic seabirds. Environ Toxicol Chem 2018;37:1084-1091. © 2017 SETAC.

Sex-specific differences in elemental movement from blood to hair

We investigated the relationships between the element concentrations in blood and hair to clarify the sex-specific differences in elemental movement from blood to hair, as we confirmed the presence of large sex-specific differences in the concentrations of certain elements in hair in our previous study. First, we compared the elemental concentrations in serum/plasma taken from healthy people ([Formula: see text] females, 142 males) and found that there were significant differences (up to 20%) between females and males in levels of phosphorus, sulfur, calcium, bromine, and lead. We then examined the sex-specific differences in the elemental transfer factors from blood to hair by analyzing plasma and hair samples that had been simultaneously collected from the same people (20 females, 21 males). Calcium and selenium showed significant differences in transfer factors from plasma to hair. Particularly, large sex-specific differences in the calcium concentration were explained by the difference in the transfer factors from blood to hair. We also examined the sex-specific differences among teenaged subjects alone ([Formula: see text] females, 9 males; average age was approximately 17 years old) and noted no significant difference in the transfer factors between sexes. Taken together, these findings indicate that the transfer factors themselves are influenced by the excretion of sex hormones.

Kinetic and Thermodynamic Control in Porphyrin and Phthalocyanine Self-Assembled Monolayers.

Porphyrins and phthalocyanines are ubiquitous in modern science and technology. Their stability, redox properties, and photoresponse make them candidates for numerous applications. Many of these applications rely on thin films, and these are critically dependent on the first monolayer. In this article, we focus on noncovalently bound self-assembled monolayers of porphyrins and phthalocyanines at the solution-solid interface with special emphasis on the kinetic and thermodynamic processes that define the films and their reaction chemistry. We first discuss the difference between film-formation kinetics and desorption kinetics from fully formed films. We then present evidence that many of these monolayers are controlled by adsorption kinetics and are not in thermodynamic equilibrium. Measurement of the solution-solid interface desorption energy by scanning tunneling microscopy is discussed, and data is presented for cobalt, nickel, and free base octaethylporphyrin. The activation energy for the desorption of these compounds into phenyloctane is about half of the computed desorption energy in vacuum, and this is discussed in terms of the role of the solvent. Preexponential factors are very low compared to desorption into vacuum, and this is attributed to a reduction in the entropy of activation due to the participation of solvent in the transition state. An example of the use of relative desorption kinetics to create a new binary surface structure is given. It is suggested that this is a synthesis route that may have been missed because of the large difference in solution concentrations required to drive binary film formation. Attention then turns to the axial reaction chemistry of metalloporphyrins and metallophthalocyanines supported on conducting surfaces. We show several examples of chemistry unique to the supported complexes: cases where the metal binds ligands more readily and cases where the substrate induces ligand loss. Understanding this new axial coordination chemistry is of great importance in catalysis, sensing, and the growth of 3D materials from a self-assembled template.