Journal: Physical Review Materials

Article Title: Phase stabilities of MgCO3 and MgCO3 -II studied by Raman spectroscopy, x-ray diffraction, and density functional theory calculations

doi: 10.1103/physrevmaterials.4.055001

Figure Lengend Snippet: FIG. 7. Raman spectra of MgCO3 (magnesite) + MgCO3-II (C2/m) obtained during decompression down to ambient conditions. Frequencies of the (C3O9)6−ring bending (light grey) are observed down to ∼40 GPa. The concomitant presence of a characteristic mode (CO2− 3 –stretching mode) of MgCO3 (magnesite) indicated in dark grey shows the coexistence of magnesite and metastable MgCO3-II. MgCO3 (magnesite) is recovered at low pressures and ambient conditions.

Article Snippet: The sample was heated from both sides with a pulsed CO2 laser (Diamond K-250 from Coherent, λ = 10.6 μm) [28].

Techniques:

Journal: Cell biochemistry and function

Article Title: Fullertubes inhibit mycobacterial viability and prevent biofilm formation by disrupting the cell wall.

doi: 10.1002/cbf.3963

Figure Lengend Snippet: FIGURE 1 Dispersions of fullerenes (C60) and fullertubes (C90) show antimicrobial activity against Mycobacterium smegmatis and Mycobacterium abscessus cells in log‐phase (104 colony‐forming units (CFUs)/mL) were exposed for 40 h with shaking at 37°C to C60 or C90 as dispersions in oleic acid:dimethyl sulfoxide (DMSO; 1:3, v/v) at final concentrations of 0.2 μg/mL or 1 μg/mL in culture medium. (A) CFUs/ mL from duplicates of a representative experiment are shown as average ± SD. (B) Viability of M. smegmatis cells exposed to C60 or C90 is shown as a percent of control cells exposed to oleic acid:DMSO. Percent survival values (average ± SD) from three independent experiments. (C) CFUs/ mL of M. abscessus cells exposed for 205 h to C60 or C90 at a concentration of 1 μg/mL. (D) Percent survival of M. abscessus compared to oleic acid:DMSO control. One‐way analysis of variance and Tukey's HSD post hoc test were performed to determine significance. *p < .05; ****p < .0001.

Article Snippet: We adapted the procedure detailed in an earlier study to probe the envelope integrity of Msm.15 Planktonic, log‐phase Msm cells were exposed to dispersions of C90 or C60 at final concentrations of 0.2 μg/mL or the oleic acid:DMSO control (0.02% v/v final concentration) for 2 h. The cells were washed with 0.85% NaCl in ultrapure water and exposed to the 2X SYTO‐9/PI solution (LIVE/ DEAD BacLight Bacterial Viability Kit, Molecular Probes) and incubated at room temperature in the dark for 15min, after which the green fluorescence (Ex.

Techniques: Activity Assay, Control, Concentration Assay

Journal: Cell biochemistry and function

Article Title: Fullertubes inhibit mycobacterial viability and prevent biofilm formation by disrupting the cell wall.

doi: 10.1002/cbf.3963

Figure Lengend Snippet: FIGURE 2 Exposure of Mycobacterium smegmatis and Mycobacterium abscessus to C60 or C90 induces changes in cell morphology. Scanning electron micrographs of untreated cells, cells exposed to 1:3 oleic acid:dimethyl sulfoxide (0.1%, v/v) and cells exposed to dispersions of C60 and C90 at 0.2 μg/mL. M. smegmatis cells were observed after 2 and 24 h and M. abscessus cells were observed after 24 h of exposure. The cells were collected over a 0.22‐micron polycarbonate filter, dried, and sputter‐coated with a gold coating at a thickness of 2 nm. The cells were imaged at a voltage of 3.00 kV and a magnification of 15,000×. Representative fields are shown for each treatment.

Article Snippet: We adapted the procedure detailed in an earlier study to probe the envelope integrity of Msm.15 Planktonic, log‐phase Msm cells were exposed to dispersions of C90 or C60 at final concentrations of 0.2 μg/mL or the oleic acid:DMSO control (0.02% v/v final concentration) for 2 h. The cells were washed with 0.85% NaCl in ultrapure water and exposed to the 2X SYTO‐9/PI solution (LIVE/ DEAD BacLight Bacterial Viability Kit, Molecular Probes) and incubated at room temperature in the dark for 15min, after which the green fluorescence (Ex.

Techniques:

Journal: Cell biochemistry and function

Article Title: Fullertubes inhibit mycobacterial viability and prevent biofilm formation by disrupting the cell wall.

doi: 10.1002/cbf.3963

Figure Lengend Snippet: FIGURE 3 Exposure of Mycobacterium smegmatis to C60 or C90 induces changes in acid‐fast staining morphology. M. smegmatis cells in log‐ phase (104colony‐forming units/mL) were exposed for 40 h with shaking at 37°C to C60 or C90 as dispersions in oleic acid:dimethyl sulfoxide (1:3, v/v) at final concentrations of 0.2 μg/mL in culture. The cells were collected and stained with carbolfuchsin for acid‐fast staining. The cells were viewed and photographed under brightfield at 1000×. Representative fields for each group across three independent experiments are depicted.

Article Snippet: We adapted the procedure detailed in an earlier study to probe the envelope integrity of Msm.15 Planktonic, log‐phase Msm cells were exposed to dispersions of C90 or C60 at final concentrations of 0.2 μg/mL or the oleic acid:DMSO control (0.02% v/v final concentration) for 2 h. The cells were washed with 0.85% NaCl in ultrapure water and exposed to the 2X SYTO‐9/PI solution (LIVE/ DEAD BacLight Bacterial Viability Kit, Molecular Probes) and incubated at room temperature in the dark for 15min, after which the green fluorescence (Ex.

Techniques: Staining

Journal: Cell biochemistry and function

Article Title: Fullertubes inhibit mycobacterial viability and prevent biofilm formation by disrupting the cell wall.

doi: 10.1002/cbf.3963

Figure Lengend Snippet: FIGURE 4 Mycobacterium smegmatis cell envelope integrity is compromised, and permeability is increased by exposure to C60 or C90. (A) The relative green (Ex. 485 nm/Em. 528 nm)/red (Ex. 530 nm/Em. 590 nm) fluorescence ratios of M. smegmatis cells treated with C60 or C90 or control cells exposed only to oleic acid:dimethyl sulfoxide (DMSO) (1:3, v/v). Cells were washed after exposure to carbon nanomaterials and then stained with a 2X SYTO‐9/propidium iodide solution. Treated cells were exposed to C60 or C90 (0.2 μg/mL) for 2 h. The ratios were calculated against the M. smegmatis + oleic acid:DMSO control and normalized using colony‐forming units (CFUs) obtained from agar plating. The kinetics of ethidium bromide (EtBr) accumulation in the presence of 0.4 µg/mL C60 (B) and C90 (C) compared to verapamil (VP, 75 μg/mL) and oleic acid:DMSO controls are shown. A representative experiment from three independent repeats is depicted. (D) The normalized fluorescence at the 60 min endpoint after EtBr accumulation in the presence of 0.4 μg/mL C60 or C90. (E) The relative green fluorescence (Ex. 485 nm/Em. 528 nm) of M. smegmatis cells treated with C60 or C90 (0.2 μg/mL) for 2 h and exposed to dichlorodihydrofluorescein diacetate. The relative green fluorescence ratios are calculated against the M. smegmatis + oleic acid:DMSO control and normalized using CFUs obtained from agar plating. Average ± SD over three independently performed experiments are depicted. (F) The normalized fluorescence at the 60 min endpoint after EtBr efflux in the presence of 0.4 μg/mL C60 or C90. Statistical significance calculated by one‐way analysis of variance with a post hoc Tukey test. *p < .05, **p < .01, ***p < .001.

Article Snippet: We adapted the procedure detailed in an earlier study to probe the envelope integrity of Msm.15 Planktonic, log‐phase Msm cells were exposed to dispersions of C90 or C60 at final concentrations of 0.2 μg/mL or the oleic acid:DMSO control (0.02% v/v final concentration) for 2 h. The cells were washed with 0.85% NaCl in ultrapure water and exposed to the 2X SYTO‐9/PI solution (LIVE/ DEAD BacLight Bacterial Viability Kit, Molecular Probes) and incubated at room temperature in the dark for 15min, after which the green fluorescence (Ex.

Techniques: Permeability, Fluorescence, Control, Staining

Journal: Cell biochemistry and function

Article Title: Fullertubes inhibit mycobacterial viability and prevent biofilm formation by disrupting the cell wall.

doi: 10.1002/cbf.3963

Figure Lengend Snippet: FIGURE 5 Fullerenes and fullertubes inhibit pellicle biofilm formation in Mycobacterium smegmatis. Cells exposed to fullertubes and fullerenes were allowed to form biofilms under static conditions at 37°C for 72 h in glass tubes. Biofilm formation was then quantified by staining with Crystal Violet and measuring absorbance at 600 nm. (A) Floating biofilm formation after 3 days in the presence of 0.2 and 0.4 μg/mL of C60 and C90 concentrations. (B) Quantitation of biofilm formation in the presence of fullertubes and fullerenes compared to controls exposed to oleic acid:dimethyl sulfoxide. Average ± SD from three independent experiments are depicted. Statistical significance was determined by one‐way analysis of variance with Tukey's post hoc test. *p < .05; ****p < .0001.

Article Snippet: We adapted the procedure detailed in an earlier study to probe the envelope integrity of Msm.15 Planktonic, log‐phase Msm cells were exposed to dispersions of C90 or C60 at final concentrations of 0.2 μg/mL or the oleic acid:DMSO control (0.02% v/v final concentration) for 2 h. The cells were washed with 0.85% NaCl in ultrapure water and exposed to the 2X SYTO‐9/PI solution (LIVE/ DEAD BacLight Bacterial Viability Kit, Molecular Probes) and incubated at room temperature in the dark for 15min, after which the green fluorescence (Ex.

Techniques: Staining, Quantitation Assay

Journal: Cell biochemistry and function

Article Title: Fullertubes inhibit mycobacterial viability and prevent biofilm formation by disrupting the cell wall.

doi: 10.1002/cbf.3963

Figure Lengend Snippet: FIGURE 6 Fullertubes and fullerenes do not induce dormancy in Mycobacterium smegmatis or show synergistic action with isoniazid. M. smegmatis (Msm) cells were exposed to C90 or C60 (0.2 μg/mL) for 2 h at 37°C, and then exposed to isoniazid at a final concentration of 2 or 10 µg/mL for an additional 24 h at 37°C. Appropriate serial dilutions were spread‐plated onto Middlebrook 7H10 agar plates or assayed for most probable numbers (MPN). Data shown as average ± SD for colony‐forming units/mL and MPN index values per milliliter from a representative experiment shown. Three independent repeats performed. The 95% confidence limits (lower, upper) for MPN were as follows: Msm + Oleic:dimethyl sulfoxide, (3.7, 42); Msm + C60, (0.46, 9.4); Msm + C90, (0.09, 1.8). Statistical significance was determined by one‐way analysis of variance with Tukey's post hoc test. ***p < .001.

Article Snippet: We adapted the procedure detailed in an earlier study to probe the envelope integrity of Msm.15 Planktonic, log‐phase Msm cells were exposed to dispersions of C90 or C60 at final concentrations of 0.2 μg/mL or the oleic acid:DMSO control (0.02% v/v final concentration) for 2 h. The cells were washed with 0.85% NaCl in ultrapure water and exposed to the 2X SYTO‐9/PI solution (LIVE/ DEAD BacLight Bacterial Viability Kit, Molecular Probes) and incubated at room temperature in the dark for 15min, after which the green fluorescence (Ex.

Techniques: Concentration Assay