Concentration Of Camphor Research Articles

A three-dimensional multiphase numerical model for the influence of Marangoni convection on Marangoni self-driven object

By means of coordinate transformation and the volume-of-fluid-level set multiphase flow method, a three-dimensional multiphase numerical model is established to simulate a Marangoni self-driven object. The forces on the Marangoni self-driven object are discussed as the driving force, viscous resistance, and pressure resistance. A typical disk-shaped, Marangoni self-driven object driven by the diffusion of camphor from its tail to water is utilized to perform a numerical study. Its motion evolution and force change in the whole process are represented quantitatively alongside the flow field and camphor concentration distribution in the flow domain. Meanwhile, the influence of Marangoni convection, which is induced by camphor diffusion at the moving gas–liquid interface, on surfer motion is surveyed. The results presented in this work can improve understanding of self-driven Marangoni propulsion since self-driven object motion and fluid movement details are difficult to acquire experimentally.

Microencapsulation of camphor using trimethylsilylcellulose

Microencapsulation of camphor by trimethylsilylcellulose was performed using oil-in-water emulsion method. Trimethylsilylcellulose (TMSC) with the DS value of 2.41 (CHN analysis) was synthesized by dissolving commercial cellulose in N, N-dimethylacetamide/LiCl followed by reacting with hexamethyldisilazane. Sodium dodecyl sulfate (SDS) in acidic aqueous solution and tetramethylammonium chloride (TMACl) in water were attempted as emulsifiers. The oil phase composed of TMSC and camphor in ethyl acetate was dispersed in emulsifier solution. The mass ratio of TMSC to camphor and emulsifier concentration were optimized to produce high quality microcapsules. Using the mass ratio of 3:7 and 1% (w/v) SDS solution gave well separated microcapsules of TMSC_C_SDS (1). The diameter size in the micron range (10–110 mm) and high camphor content (∼21.07%) were obtained from this sample. The larger size of the capsules obtained from TMACl system indicated the coalescence of the oil droplets. The hydrolysis of the external surface of the microcapsules was observed in the SDS system. However, this caused a minor effect on the cellulose stability in TMSC_C_SDS (1). The freshly prepared microcapsules of TMSC_C_SDS (1) showed the fast release of camphor during first 2 h and reached the equilibrium after 7 h.

Effect of Limonene, Camphor and Menthol on Cariogenic Oral Pathogens

Streptococci, Lactobacillus, and fungi take a significant role in caries development. It confirms the importance of controlling these microorganisms to prevent dental caries. Chemical methods are used to prevent plaque accumulation in addition to physical methods, which include the use of chemical mouthwashes like chlorhexidine. Chemicals, while beneficial, have many side effects. This study aimed to find the herbal compounds having fewer side effects. Three monoterpenes, menthol, limonene, and camphor in plants that have been shown to have an antibacterial effect have been prepared and by sensitization drug in 96-well plates exposed to Streptococcus mutans, Streptococcus salivarius, Streptococcus sobrinus, Lactobacillus casei, and several Candida spp.. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum fungicidal concentration (MFC) were identified. The menthol had the best inhibitory effect on yeast growth (MIC = 0.5-1 µg/ml), and the limonene composition had the lowest fungicidal concentration against Candida spp. (MFC = 1.9 µg/ml). Menthol at a concentration of 128 μg/mL had no bactericidal effect while it killed Lactobacillus. Strep.salivarius were killed at a concentration of 128 μg/ml of limonene. At the same concentration of camphor, Strep.mutans were killed. Monoterpenes exhibited great antimicrobial activity, which can use in mouthwashes formulation. Keywords: Monoterpenes, Streptococcus mutans, Candida albicans, Anti-Bacterial Compounds, Limonene, Menthol

Influence of Volatile Components from ‘Qiyueju’ (Chrysanthemum morifolium Ramat.) Flowerheads on the Mycelial Growth of Pleurotus ostreatus

Chrysanthemum is a traditional edible and medicinal flower, has many medicinal properties, and is used in the food and pharmaceutical industries. This study aimed to investigate the chemical composition of volatile components from ‘Qiyueju’ (Chrysanthemum morifolium Ramat.) flowerheads and their effect on Pleurotus ostreatus mycelial growth. The flower has been collected from the Yunwu Mountain region (Guizhou Province, China), and volatile components of ‘Qiyueju’ flowerheads have been obtained using headspace solid-phase micro-extraction (SPME). Gas chromatography-mass spectrometry (GC-MS) analysis of the volatile components has been carried out to reveal its chemical composition. A total of 67 volatile components have been identified, accounting for 95.28 % of the total volatile components. These volatile components have been dominated by camphor (48.64 %), followed by bornyl acetate (3.94 %), cis-β-Farnesene (3.55 %), sabinene (3.00 %), α-terpineol (2.65 %), Z,E-α-farnesene (2.55 %), and 1,8-cineole (2.43 %). In particular, the value of camphor was significantly above the range from 0 to 44.6 % in previous studies, most probably due to species, geographical location, seasonal factors, climatic conditions, and harvest time. The influence of volatile components on the mycelial growth of P. ostreatus was investigated using the growth rate method. The four selected major components exhibited strong sensitivity to P. ostreatus after five days. Notably, the fungus possessed the strongest sensitivity (EC50=0.175 μg/ml) and the best mycelial growth rate values of 6.10±0.03 mm/d when the camphor concentration was 1.25 μg/ml (P<0.05). Camphor also produced the best percentage of induction (47.30±8.96 %) at the same concentration. The four selected major components, especially camphor, from ‘Qiyueju’ flowerheads have some potential development value in terms of P. ostreatus culture medium and may be useful in the search for newer annexing agents in the culture substrate of edible fungi.

DEVELOPMENT AND EVALUATION OF MOUTH DISSOLVING ANTIINFLAMMATORY TABLET CONTAINING FENOPROFEN

Fenoprofen belongs to Biopharmaceutical Classification System (BCS) class II drugs which are poorly soluble in water. The objective of present research work was to prepare fast dissolving tablets of fenoprofen using varying concentrations of three different sublimating agents to improve the dissolution rate. Seven formulations were prepared containing different concentrations of camphor, ammonium bicarbonate and thymol as sublimating agent along with primogel as a superdisintegrant. Tablets were manufactured by direct compression method. The prepared tablets were evaluated for pre-compression and post-compression parameters result, for all formulations result was within official limits. DSC studies revealed that there were no interactions between the drug and the excipients used. From in vitro drug release studies the dissolution studies, cumulative percentage of drug release versus time was evaluated. It also reflects that the formulations F4 and F15 containing 45 mg and 67.5 mg of thymol respectively showed fast drug release of 100.00% and 99.56 % respectively in 30 minutes as compared with formulations containing other sublimating agents. Among all the formulations, F6 and F7 tablets showed complete drug release within 30 minutes and rapid dissolution.

Novel\ufeff markers to early detect degradation on cellulose nitrate-based heritage at the submicrometer level using synchrotron UV\u2013VIS multispectral luminescence

Cellulose nitrate (CN) is an intrinsically unstable material that puts at risk the preservation of a great variety of objects in heritage collections, also posing threats to human health. For this reason, a detailed investigation of its degradation mechanisms is necessary to develop sustainable conservation strategies. To investigate novel probes of degradation, we implemented deep UV photoluminescence micro spectral-imaging, for the first time, to characterize a corpus of historical systems composed of cellulose nitrate. The analysis of cinematographic films and everyday objects dated from the nineteenth c./early twentieth c. (Perlov's collection), as well as of photo-aged CN and celluloid references allowed the identification of novel markers that correlate with different stages of CN degradation in artworks, providing insight into the role played by plasticizers, fillers, and other additives in stability. By comparison with photoaged references of CN and celluloid (70% CN and 30% camphor), it was possible to correlate camphor concentration with a higher rate of degradation of the cinematographic films. Furthermore, the present study investigates, at the sub-microscale, materials heterogeneity that correlates to the artworks' history, associating the different emission profiles of zinc oxide to specific color formulations used in the late nineteenth and early twentieth centuries.

Partial Opening of Cytochrome P450cam (CYP101A1) Is Driven by Allostery and Putidaredoxin Binding.

Cytochrome P450cam (CYP101A1) catalyzes the regio- and stereo-specific 5-exo-hydroxylation of camphor via a multistep catalytic cycle that involves two-electron transfer steps, with an absolute requirement that the second electron be donated by the ferrodoxin, putidaredoxin (Pdx). Whether P450cam, once camphor has bound to the active site and the substrate entry channel has closed, opens up upon Pdx binding, during the second electron transfer step, or it remains closed is still a matter of debate. A potential allosteric site for camphor binding has been identified and postulated to play a role in the binding of Pdx. Here, we have revisited paramagnetic NMR spectroscopy data and determined a heterogeneous ensemble of structures that explains the data, provides a complete representation of the P450cam/Pdx complex in solution, and reconciles alternative hypotheses. The allosteric camphor binding site is always present, and the conformational changes induced by camphor binding to this site facilitates Pdx binding. We also determined that the state to which Pdx binds comprises an ensemble of structures that have features of both the open and closed state. These results demonstrate that there is a finely balanced interaction between allosteric camphor binding and the binding of Pdx at high camphor concentrations.

Covalent conjugation of single-walled carbon nanotube with CYP101 mutant for direct electrocatalysis

Covalent linkage between the single-walled carbon nanotube (SWCNT) and CYP101 through a specific site of the enzyme can provide a novel method of designing efficient enzyme electrodes using this prototype cytochrome P450 enzyme. We have chemically modified the SWCNT with linker 4-carboxy phenyl maleimide (CPMI) containing maleimide functional groups. The enzyme was covalently attached on to the SWCNT through the maleimide group of the linker (CPMI) to the thiolate group of the surface exposed Cys 58 or Cys 136 of the CYP101 forming a covalently immobilized protein on the nanotube. Thin film of the modified SWCNT-CPMI-CYP101conjugate was made on a glassy carbon (GC) electrode. Direct electrochemistry of the substrate (camphor)-bound enzyme was studied using this immobilized enzyme electrode system and the redox potential was found to be −320mV vs Ag/AgCl (3 M KCl), which agrees with the redox potential of the substrate bound enzyme reported earlier.The electrochemically driven enzymatic mono-oxygenation of camphor by this immobilized enzyme electrode system was studied by measurement of the catalytic current at different concentrations of camphor. The catalytic current was found to increase with increasing concentration of camphor in presence of oxygen. The product formed during the catalysis was identified by mass-spectrometry as hydroxy-camphor.

Arbuscular mycorrhizae and rhizobacteria improve growth, nutritional status and essential oil production in Ocimum basilicum and Satureja hortensis

The effects of arbuscular mycorrhiza fungi (AMF) species (Glomus intraradices and G. mosseae), nitrogen (N) fertilizer and plant growth-promoting rhizobacteria (PGPR) on growth characteristics, essential oil (EO) content, nutrient uptake and components of medicinal plants basil (Ocimum basilicum) and satureja (Satureja hortensis) were studied. The use of these fertilizers significantly (P < 0.05) increased plant height, root length, fresh and dry weights of shoots and roots, number of shoot branches and number of inflorescences per plant, EO content, phosphorus (P), nitrogen (N), iron (Fe), potassium (K), and copper (Cu) content. Moreover, application of AMF and PGPR significantly (P < 0.05) enhanced linalol, methyl chavicol, trans-geraniol, camphor and limonene concentrations in basil EO and carvacrol, thymol, p-cymene, α-terpinene and γ-terpinene in satureja EO components. G. mosseae application achieved the highest increases in basil and satureja EO percentage by 39 % and 25 %, respectively, compared to plants treated with mineral fertilizer, and 80 % and 50 %, respectively, compared to unfertilized plants. The highest N, K, Fe and P concentrations in basil and satureja were obtained when PGPR or G. mosseae were used. This study shows that application of biofertilizers not only improves yields in medicinal plants, but they also play a significant role in increasing their bioactive compounds and plant nutrition.

171 Inhibition of pure culture Salmonella Newport by camphor and eucalyptol in vitro

Abstract Volatile oils have potent antimicrobial activities that have allowed them to be used as food preservatives for millennia. The impact of concentrations of the monoterpene volatile oils camphor and eucalyptol on the growth of the cattle and foodborne pathogen Salmonella Newport was evaluated by examining changes in optical density (600 nm). Cultures of S. Newport were grown in Tryptic Soy Broth (TSB) overnight and inoculated into fresh TSB tubes at an initial concentration of ~106 CFU/mL in the presence of monoterpene concentrations (0 – 9.85 mM) and were incubated at 39℃. Final optical density and maximum specific growth rates (h-1) were determined. Data were analyzed using a PROC GLM procedure in SAS 9.4 for a 2*5 repeated measure factorial. Overall, there was a concentration (P &amp;lt; 0.01) and a time by concentration (P &amp;lt; 0.01) effect, but no differences between monoterpene types (P = 0.28) were observed. Camphor and eucalyptol concentrations of 3.28 and 9.85 mM reduced (P &amp;lt; 0.05) S. Newport growth. The highest dose (9.85 mM) of camphor and eucalyptol immediately inhibited S. Newport growth. Maximum specific growth rate was reduced (P &amp;lt; 0.01) by both monoterpenes compared to controls, most particularly at 9.85 mM concentrations, but were not different between the two monoterpenes. Collectively, our results suggest that monoterpenes at high concentrations can reduce the growth of Salmonella Newport; however, to fully understand practical implementation of monoterpene effects on foodborne or animal pathogens, studies using both mixed culture and in vivo models are needed. Tuesday, July 21, 2020

Unravelling camphor mediated synthesis of TiO2 nanorods over shape memory alloy for efficient energy harvesting

We demonstrated a cost-effective and scalablechemical vapor deposition(CVD) process for the production of high quality and dense rutile titanium dioxide nanorods (R-TiO2 NR) based on camphor (Cinnamomum camphora) decomposition overshape memory alloy (nitinol). The topography of the camphor-based R-TiO2 NR was studied underfield emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) which revealed high coverage of R-TiO2 NR over the substrate. The phase purity of R-TiO2 NR was established by X-ray diffraction measurements performed at different camphor concentrations and substrate temperatures. Raman spectroscopy and X-ray photoelectron spectroscopyconfirmed the chemical and the elemental composition of the nanorods grown over nitinol, which suggest the formation of high-quality R-TiO2 NR. Further, R-TiO2 NR was used as photoanode in 1 M KOH solution for efficient energy harvesting application by indicating a high photocurrent density of 550 µA/cm2 at 1.23 V vs RHE (reversible hydrogen electrode), indicating excellent light trapping mechanism with efficient charge separation and extraction. The proposed CVD process is a suitable method for large scale production of R-TiO2 NR over nitinol, which can be potentially employed in sensors and various other biomedical applications.

Organic ultraviolet filters in nearshore waters and in the invasive lionfish (Pterois volitans) in Grenada, West Indies.

Sunscreens and other personal care products use organic ultraviolet (UV) filters such as oxybenzone, 4-methylbenzylidene camphor, Padimate-O, and octyl methoxycinnamate to prevent damage to human skin. While these compounds are effective at preventing sunburn, they have a demonstrated negative effect on cells and tissues across taxonomic levels. These compounds have a relatively short half-life in seawater but are continuously re-introduced via recreational activities and wastewater discharge, making them environmentally persistent. Because of this, testing seawater samples for the presence of these compounds may not be reflective of their abundance in the environment. Bioaccumulation of organic ultraviolet filters in a high-trophic level predator may provide greater insight to the presence and persistence of these compounds. To address this, the present study collected seawater samples as well as muscle and stomach content samples from the invasive Pacific lionfish (Pterois volitans) in the nearshore waters of Grenada, West Indies to examine the use of lionfish as potential bioindicator species. Seawater and lionfish samples were collected at four sites that are near point sources of wastewater discharge and that receive a high number of visitors each year. Samples were tested for the presence and concentrations of oxybenzone, 4-methylbenzylidene camphor (4-MBC), Padimate-O, and octyl methoxycinnamate (OMC) using liquid chromatography-mass spectrometry. Oxybenzone residues were detected in 60% of seawater samples and OMC residues were detected in 20% of seawater samples. Seawater samples collected in the surface waters near Grenada’s main beach had oxybenzone concentrations more than ten times higher than seawater samples collected in less frequently visited areas and the highest prevalence of UV filters in lionfish. Residues of oxybenzone were detected in 35% of lionfish muscle and 4-MBC residues were detected in 12% of lionfish muscle. Padimate-O was not detected in either seawater or lionfish samples. No organic UV filters were detected in lionfish stomach contents. Histopathologic examination of lionfish demonstrated no significant findings attributed to UV filter toxicity. These findings report UV filter residue levels for the first time in inshore waters in Grenada. Results indicate that lionfish may be bioaccumulating residues and may be a useful sentinel model for monitoring organic ultraviolet filters in the Caribbean Sea.

Controlled Island Formation of Large-Area Graphene Sheets by Atmospheric Chemical Vapor Deposition: Role of Natural Camphor.

Camphor-based mono-/bilayer graphene (MLG) sheets have been synthesized by very facile atmospheric chemical vapor deposition processes on Si/SiO2, soda lime glass, and flexible polyethylene terephthalate films. The effect of camphor concentration with respect to distance between camphor and the Cu foil (D) has been varied to investigate the controlled formation of a homogeneous graphene sheet over a large area on Cu foil. Raman studies show a remarkable effect of camphor at a typical distance (D) to form a monolayer to multilayer graphene (MULG) sheet. The signature of MLG to MULG sheets appears due to increase in the number of nucleation sites, even over the subsequent domains that contribute stacks of graphene over each other as observed by high-resolution transmission electron microscopy images. Moreover, the increase in camphor concentration at a particular distance generates more defect states in graphene as denoted by D band at 1360 cm–1. Uniform distribution of large-area MLG demonstrates an intense 2D/G ratio of ∼2.3. Electrical and optical measurements show a sheet resistance of ∼1 kΩ/sq with a maximum transmittance of ∼88% at 550 nm for low camphor concentration. An improvement in the rectification and photodiode behavior is observed from the diodes fabricated on n-Si/MULG as compared to n-Si/MLG in dark and light conditions.

Oxidative stress-mediated apoptotic cell death induced by camphor in sod1-deficient Schizosaccharomyces pombe.

Camphor is one of the monoterpenes widely used in cosmetics, pharmaceutics and the food industry. In this study, we aimed to assess the oxidative, cytotoxic and apoptotic effects of camphor on the fission yeast (Schizosaccharomyces pombe), which is a promising unicellular model organism in mechanistic toxicology and cell biology. Since Sod1 is the main radical scavenger in the cell, we used sod1 mutants to understand whether camphor-induced ROS accumulation caused higher cytotoxicity and apoptosis. Camphor exposure (0-2000 mg L-1) caused significant cytotoxicity in yeast, particularly in sod1Δ cells. DCFDA (2,7-dichlorodihydrofluorescein diacetate) fluorescence and NBT (p-nitro-blue tetrazolium chloride) reduction increased (at least 2.5-3-fold in sod1Δ cells) in correlation with camphor concentrations (800-1200 mg L-1), showing higher ROS levels and oxidative stress. Moreover, cells, stained with acridine orange/ethidium bromide, showed an apoptotic morphology with nuclear fragmentation and condensation. DAPI (4',6-diamidino-2-phenylindole) staining was used to validate the apoptotic nuclear morphology. Dramatically increased mitochondrial impairment, which was higher in sod1Δ cells than in wild type cells, was shown by rhodamine 123 staining. In conclusion, camphor-induced excessive ROS production, which could not be prevented significantly in sod1 mutants, caused a dramatic increase in mortality rates due to intrinsic apoptosis revealed by mitochondrial impairment and apoptotic nuclear morphology. The potential effects of camphor on apoptotic cell death and the underlying mechanisms were clarified in the unicellular eukaryotic model, S. pombe.

Chemical characterization of Lavandula dentata L. essential oils grown in Uberaba-MG

ABSTRACT: The essential oils of the different parts of Lavandula dentata L. (inflorescences and aerial part without inflorescences) collected in the city of Uberaba (minas Gerais State)were obtained by hydro distillation, and their chemical composition was determined by gas chromatography coupled to mass spectrometry and compared to the chemical composition of essential oil of Lavandula hybrida and Lavandula officinalis. It was observed that the essential oils of the studied species have varied chemical composition and are composed mainly of monoterpenes. The essential oils of L. hybrida and L. officinalis showed a higher concentration of linalool and linaline acetate, while L. dentata L. presented higher concentration of fenchone, eucalyptol and camphor. Results indicate that the essential oil composition of L. dentata L. grown in Uberaba is similar to those produced in Curitiba - PR, providing a promising perspective for the cultivation and extraction of essential oils of this species in Minas Gerais.

Synthesis and characterization of carbon nanospheres by catalytic CVD method

Carbon nanospheres (CNSs) were successfully prepared and synthesized by Catalytic Chemical Vapor Deposition (CCVD) by using camphor as carbon source only, over iron Cobalt (Fe-Co) saturated zeolite at temperature between (700 oC and 900 °C), with different concentrations of camphor, and reaction time. The synthesized CNSs were characterized using Scanning Electron Microscopy (SEM), X-ray diffraction spectroscopy (XRD), and Fourier Transform Infrared (FTIR). The carbon spheres in different sizes between 100 nm and 1000 nm were investigated. This work has done by two parts, first preparation of the metallic catalyst and second part formation CNSs by heat treatment.

Power law observed in the motion of an asymmetric camphor boat under viscous conditions.

We investigated the velocity of an asymmetric camphor boat moving on aqueous solutions with glycerol. The viscosity was controlled by using several concentrations of glycerol into the solution. The velocity decreased with an increase in the glycerol concentration. We proposed a phenomenological model, and we showed that the velocity decreased with an increase in the viscosity according to power law. Our experimental result agreed with the one obtained from our model. These results suggest that a decay length of the camphor concentration at the front side of the boat is sufficiently shorter than that of the rear side.

Acaricidal and insecticidal properties of Coriandrum sativum oils and their major constituents extracted by three different methods against stored product pests

Essential oils of Coriandrum sativum were extracted by three different methods, including steam distillation (SDE), solvent (SE) and supercritical fluid extraction (SFE), to determine their acaricidal and insecticidal properties against Plodia interpunctella, Sitotroga cerealella and Tyrophagus putrescentiae. The fumigant bioassay against P. interpunctella, S. cerealella and T. putrescentiae revealed the strongest activity (LD50 9.38, 18.76 and 4.19 μg/cm3) of oil obtained via SDE, followed by extraction via SE (LD50 > 75.20, 21.11, and > 75.20 μg/cm3) and SFE (LD50 > 75.20, 27.36, and > 75.20 μg/cm3). The contact bioassay against T. putrescentiae revealed the most potent activities of oil obtained via SDE (LD50 19.29 μg/cm2), followed by oil via SE and SFE. The chemical composition of C. sativum oils obtained by SDE, HE and SFE was analyzed by GC–MS. The C. sativum oil obtained by SDE contained linalool (66.80%) compared with oils obtained by SE and SFE (70.67–70.80%). However, camphor (6.46%) was detected in SDE but not in the other two extracts. Based on the LD50 values of six major compounds derived from the three C. sativum oils against P. interpunctella, S. cerealella and T. putresceentiae, camphor was considered the most active (2.32, 19.31 and 3.24 μg/cm3, respectively) insecticide. The three values were about real camphor concentration in the oil via SDE. These results indicate that camphor contributes to the acaricidal and insecticidal activities of oil extracted via SDE of C. sativum seeds.

Effects of pure plant secondary metabolites on methane production, rumen fermentation and rumen bacteria populations in vitro.

In this study, the effects of seven pure plant secondary metabolites (PSMs) on rumen fermentation, methane (CH4 ) production and rumen bacterial community composition were determined. Two in vitro trials were conducted. In trial 1, nine concentrations of 8-hydroxyquinoline, α-terpineol, camphor, bornyl acetate, α-pinene, thymoquinone and thymol were incubated on separate days using in vitro 24-hr batch incubations. All compounds tested demonstrated the ability to alter rumen fermentation parameters and decrease CH4 production. However, effective concentrations differed among individual PSMs. The lowest concentrations that reduced (p<.05) CH4 production were as follows: 8mg/L of 8-hydroxyquinoline, 120mg/L of thymoquinone, 240mg/L of thymol and 480mg/L of α-terpineol, camphor, bornyl acetate and α-pinene. These concentrations were selected for use in trial 2. In trial 2, PSMs were incubated in one run. Methane was decreased (p<.05) by all PSMs at selected concentrations. However, only 8-hydroxyquinoline, bornyl acetate and thymoquinone decreased (p<.05) CH4 relative to volatile fatty acids (VFAs). Based on denaturing gradient gel electrophoresis analysis, different PSMs changed the composition of bacterial communities to different extents. As revealed by Ion Torrent sequencing, the effects of PSMs on relative abundance were most pronounced in the predominant families, especially in Lachnospiraceae, Succinivibrionaceae, Prevotellaceae, unclassified Clostridiales and Ruminococcaceae. The CH4 production was correlated negatively (-.72; p<.05) with relative abundance of Succinivibrionaceae and positively with relative abundance of Ruminococcaceae (.86; p<.05). In summary, this study identified three pure PSMs (8hydroxyquinoline, bornyl acetate and thymoquinone) with potentially promising effects on rumen CH4 production. The PSMs tested in this study demonstrated considerable impact on rumen bacterial communities even at the lowest concentrations that decreased CH4 production. The findings from this study may help to elucidate how PSMs affect rumen bacterial fermentation.

Period of Oscillatory Motion of a Camphor Boat Determined by the Dissolution and Diffusion of Camphor Molecules.

Here, we investigated the oscillatory motion of a camphor boat on water to clarify how the dynamics of camphor concentration profile determines the period of oscillation. The boat, which was made of a plastic plate and a camphor disk, was glued below the plate at a distance from the edge. The dependence of oscillation period on temperature and viscosity of the water phase was measured in experiments. We reproduced the experimental results by calculating the period of oscillatory motion by considering the experimental values of physicochemical parameters describing the time evolution of camphor concentration profile and the friction acting on a boat, such as diffusion and dissolution rates of camphor, viscosity of the water phase, and the threshold concentration of camphor necessary to accelerate the boat from the resting state. The increase in the period of oscillatory motion at low temperatures was explained by the reduced dissolution rate of camphor into the water phase.