Science Progress (2002), 85 (4)

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Science Progress (2002), 85 (4), 297–317

Single crystal time-of-flight

neutron diffraction

J. PETERS AND W. JAUCH

The last century has seen a large development in diffraction techniques.

The time-of-flight neutron diffraction method is now so advanced that it

provides high precision results for position and thermal parameters, which

are complementary to other diffraction results from X-ray sources. Here we

review the history of neutron sources, the difficulties encountered with the

time-of-flight technique and an outlook for applications. In this context, we

will show the limitations of existing neutron sources and the expected

advantages of new spallation neutron sources. An overview of all corrections

to be taken into account with the wavelength-sorting technique will be

presented as well as actual results, how to overcome such problems, and

the special difficulty of integration of three-dimensional Bragg peaks.

Science Progress (2002), 85 (4), 319–345

Microporous materials

MARTIN P. ATTFIELD

All materials possess interatomic or interionic voids that are typically too

small for any molecular species to enter. However, there is a class of

crystalline materials that contain internal voids, and apertures, that are

large enough for molecular species to enter and pass through. These

materials are termed microporous and form a highly diverse group of

compounds that may be synthesised or occur as natural minerals. The composition

of microporous materials ranges from being exclusively inorganic

to inorganic-organic hybrids and their applications vary from 1 Mton

annual usage in detergents, to hosts for superconducting carbon nanotubes.

In this contribution, new and mature aspects of the synthesis, scope,

modification and application of microporous materials are covered to

provide the reader with an overview of this exciting field of materials

chemistry.

Science Progress (2002), 85 (4), 347–358

Comparative biology of gd T cells

ZHENG W. CHEN

Accumulative evidence suggests that resident gd T cells in epithelia are

biologically distinct from systemic gd T cells in the circulation. Murine

resident gd T cells have innate immune characteristics and play an important

role in tissue homeostasis after damages. In contrast, a unique subset

of circulating gd T cells in primates, like ab T cells, can mount adaptive

immune responses in infections. This article compares biological features

between resident and circulating gd T cells.

Science Progress (2002), 85 (4), 359–367

Gastrointestinal Diseases of

Napoleon in Saint Helena: causes

of death

JACQUES DI COSTANZO

The fact that Napoleon Ist died from gastric cancer seems to be well established.

Arguments for the hypothesis of chronic arsenic poisoning have

recently been developed in the literature. This study, focused on the gastrointestinal

diseases of Napoleon in Saint Helena, is based on a confrontation

between the clinical semiological anamnesis and the anatomical

data in the autopsy report by F. Antommarchi. Napoleon presented several

gastrointestinal diseases: gall-bladder lithiasis complicated with angiocholitis,

chronic colitis and certainly a gastric cancer. Death was consecutive

to perforation of the gastric lesion leading to haemorragic vomitis and

multiorgan failure. The description of the gastric lesions during autopsy is

consistent with the diagnosis of cancer. The course of the clinical events is

closely correlated with the anatomic lesions. There is strong evidence that

Napoleon died from an acute complication of his gastric disease.