CARBON nanotubes1 are expected to have a wide variety of interesting properties. Capillarity in open tubes has already been demonstrated2–5, while predictions regarding their electronic structure6–8 and mechanical strength9 remain to be tested. To examine the properties of these structures, one needs tubes with well defined morphologies, length, thickness and a number of concentric shells; but the normal carbon-arc synthesis10,11 yields a range of tube types. In particular, most calculations have been concerned with single-shell tubes, whereas the carbon-arc synthesis produces almost entirely multi-shell tubes. Here we report the synthesis of abundant single-shell tubes with diameters of about one nanometre. Whereas the multi-shell nanotubes are formed on the carbon cathode, these single-shell tubes grow in the gas phase. Electron diffraction from a single tube allows us to confirm the helical arrangement of carbon hexagons deduced previously for multi-shell tubes1.

Single-shell carbon nanotubes of 1-nm diameter

The interest in nanoscale materials stems from the fact that new properties are acquired at this length scale and, equally important, that these properties * To whom correspondence should be addressed. Phone, 404-8940292; fax, 404-894-0294; e-mail, mostafa.el-sayed@ chemistry.gatech.edu. † Case Western Reserve UniversitysMillis 2258. ‡ Phone, 216-368-5918; fax, 216-368-3006; e-mail, burda@case.edu. § Georgia Institute of Technology. 1025 Chem. Rev. 2005, 105, 1025−1102

Chemistry and properties of nanocrystals of different shapes.

Worldwide commercial interest in carbon nanotubes (CNTs) is reflected in a production capacity that presently exceeds several thousand tons per year. Currently, bulk CNT powders are incorporated in diverse commercial products ranging from rechargeable batteries, automotive parts, and sporting goods to boat hulls and water filters. Advances in CNT synthesis, purification, and chemical modification are enabling integration of CNTs in thin-film electronics and large-area coatings. Although not yet providing compelling mechanical strength or electrical or thermal conductivities for many applications, CNT yarns and sheets already have promising performance for applications including supercapacitors, actuators, and lightweight electromagnetic shields.

/pdf/carbon-nanotubes-present-and-future-commercial-applications-1nhq3xy4hh.pdf

Carbon Nanotubes: Present and Future Commercial Applications

Nanoparticles — particles in the size range 1–100 nm — are emerging as a class of therapeutics for cancer. Early clinical results suggest that nanoparticle therapeutics can
show enhanced efficacy, while simultaneously reducing side effects, owing to properties such as more targeted localization in tumours and active cellular uptake. Here, we
highlight the features of nanoparticle therapeutics that distinguish them from previous anticancer therapies, and describe how these features provide the potential for
therapeutic effects that are not achievable with other modalities. While large numbers of preclinical studies have been published, the emphasis here is placed on preclinical and clinical studies that are likely to affect clinical investigations and their implications for advancing the treatment of patients with cancer.

Nanoparticle therapeutics: an emerging treatment modality for cancer

Department of Materials Science, University of Patras, 26504 Rio Patras, Greece, Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vass. Constantinou Avenue, 116 35 Athens, Greece, Institut de Biologie Moleculaire et Cellulaire, UPR9021 CNRS, Immunologie et Chimie Therapeutiques, 67084 Strasbourg, France, and Dipartimento di Scienze Farmaceutiche, Universita di Trieste, Piazzale Europa 1, 34127 Trieste, Italy

Chemistry of Carbon Nanotubes

The reaction between B(C
 6
F
 5
)
 3
 and
[Fe(η-C
 5
H
 5
)(CO)
 2
Me] gave the
unexpected product
[Fe{C
 6
F
 4
C(O)Me-2}(η-C
 5
H

 5
)(CO)] 1 which reacts with the donor molecules
L = PMe
 3
, PPh
 3
 or Bu
 t
NC
giving
[Fe{C
 6
F
 4
C(O)Me-2}(η-C
 5
H

 5
)L].* Likewise
[{Fe[C
 6
F
 4
C(O)Me-2](η-C
 5
H
 
5
)}
 2
(µ-dppe)]* was formed from 1 and
Ph
 2
P(CH
 2
)
 2
PPh
 2
 (dppe). The
formation of the compound where L = PMe
 3
 is
shown to proceed via initial formation of
[Fe{C
 6
F
 4
C(O)Me-2}(η-C
 5
H

 5
)(CO)(PMe
 3
)]*. The reaction between
B(C
 6
F
 5
)
 3
 and
[M(η-C
 5
H
 5
)(CO)
 3
Me]
(M = Mo or W) gave the compounds
[M{C
 6
F
 4
C(O)Me-2}(η-C
 5
H

 5
)(CO)
 2
]. The compounds
[M{C
 6
F
 3
X-5-C(O)Me-2}(η-C
 5

H
 5
)(CO)
 2
]* (M = Mo or W) where
X = H were prepared from the compounds where
X = F via unusual C–F bond-activation
reactions. The compound
[Fe{C
 6
F
 3
H-5-C(O)Me-2}(η-C
 5

H
 5
)(PMe
 3
)] was prepared by photolysis of a
mixture of
[Fe{C
 6
F
 3
H-5-C(O)Me-2}(η-C
 5

H
 5
)(CO)] and PMe
 3
. The asterisk indicates
the crystal structure has been determined.

Synthesis of fluorophenyl derivatives of iron, molybdenum and tungstenvia B(C6F5)3 and unusualcarbon–fluorine bond reactions

An alternative to the Balhausen and Alcock models for bis-(π-cyclopentadienyl)metal systems, based on new structural data, is described.

A bonding model for bent bis-(π-cyclopentadienyl) metal compounds

Maximal static expiratory and inspiratory mouth pressures (PEmax and PImax) and quadriceps femoris muscle strength were measured in 25 patients aged 16-28 years with cystic fibrosis (mean FEV1 46% predicted). Mean (SD) PEmax was 64% (18%) predicted (below 75% predicted in 16 of the 25 patients), and PImax was 64% (24%) predicted (below 75% predicted in 14 patients). Quadriceps muscle strength was 68% (20%) predicted (below 75% predicted in 17 patients). The relatively small reduction in respiratory muscle strength in these patients was unlikely to have contributed appreciably to their respiratory problems.

https://thorax.bmj.com/content/thoraxjnl/45/10/750.full.pdf

Respiratory muscle function in cystic fibrosis.

The effect of intravenous aminophylline on the contractile function of the diaphragm was studied in four normal subjects. The contractility of the diaphragm was assessed by the measurement of transdiaphragmatic pressure (Pdi) after right phrenic nerve stimulation at 1 Hz. Pdi was measured before and during aminophylline infusion (6 mg/kg over 30 minutes), during which therapeutic concentrations of theophylline were attained (mean 13.8 mg/l, range 8.5-20.2). The Pdi achieved was not affected by aminophylline. This result suggests that theophylline at therapeutic concentrations has little effect on the contractility of the normal human diaphragm.

https://thorax.bmj.com/content/thoraxjnl/40/4/288.full.pdf

Malcolm L. H. Green

Papers

Synthesis of fluorophenyl derivatives of iron, molybdenum and tungstenvia B(C6F5)3 and unusualcarbon–fluorine bond reactions

A bonding model for bent bis-(π-cyclopentadienyl) metal compounds

Respiratory muscle function in cystic fibrosis.

Effect of aminophylline on the human diaphragm.

Electron beam induced in situ clusterisation of 1D ZrCl4 chains within single-walled carbon nanotubes