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Describes the use of laboratory experiments termed hands-on demonstrations that are designed to reinforce the concepts covered in lecture with emphasis on maximizing the sense content (sight, smell, hearing) to improve retention by the student. (GS)

Describes a laboratory teaching method in which students are given a simulated research problem to solve in groups by planning and laboratory work. (MLH)

Modern astronomical spectrographs continue to require accurate high resolution atomic data for interpretation of many astrophysical spectra. The Imperial College London laboratory astrophysics program using high resolution Fourier Transform spectrometry is described.

Background High-throughput sequencing of cell-free DNA fragments found in human plasma has been used to non-invasively detect fetal aneuploidy, monitor organ transplants and investigate tumor DNA. However, many biological properties of this extracellular genetic material remain unknown. Research that further characterizes circulating DNA could substantially increase its diagnostic value by allowing the application of more sophisticated bioinformatics tools that lead to an improved signal to noise ratio in the sequencing data. Methods In this study, we investigate various features of cell-free DNA in plasma using deep-sequencing data from two pregnant women (>70X, >50X) and compare them with matched cellular DNA. We utilize a descriptive approach to examine how the biological cleavage of cell-free DNA affects different sequence signatures such as fragment lengths, sequence motifs at fragment ends and the distribution of cleavage sites along the genome. Results We show that the size distributions of these cell-free DNA molecules are dependent on their autosomal and mitochondrial origin as well as the genomic location within chromosomes. DNA mapping to particular microsatellites and alpha repeat elements display unique size signatures. We show how cell-free fragments occur in clusters along the genome, localizing to nucleosomal arrays and are preferentially cleaved at linker regions by correlating the mapping locations of these fragments with ENCODE annotation of chromatin organization. Our work further demonstrates that cell-free autosomal DNA cleavage is sequence dependent. The region spanning up to 10 positions on either side of the DNA cleavage site show a consistent pattern of preference for specific nucleotides. This sequence motif is present in cleavage sites localized to nucleosomal cores and linker regions but is absent in nucleosome-free mitochondrial DNA. Conclusions These background signals in cell-free DNA sequencing data stem from the non-random biological cleavage of these fragments. This sequence structure can be harnessed to improve bioinformatics algorithms, in particular for CNV and structural variant detection. Descriptive measures for cell-free DNA features developed here could also be used in biomarker analysis to monitor the changes that occur during different pathological conditions. Electronic supplementary material The online version of this article (doi:10.1186/s12920-015-0107-z) contains supplementary material, which is available to authorized users.

The e(0,0) (D 2Σ+–X 2Πr) band of NO has been recorded by using a vacuum ultraviolet Fourier transform spectrometer from Imperial College, London, with synchrotron radiation at the Photon Factory, KEK, Japan, as a continuum light source. Analysis of the e(0,0) band provides accurate rotational line positions and term values as well as the photoabsorption cross sections. Molecular constants of the v=0 level of the D 2Σ state have been determined as T0=53 291.10±0.10 cm−1, B0=1.991 07±0.000 05 cm−1, and D0=(6.6±0.1)×10−6 cm−1. Accurate rotational line strengths have also been obtained and the sum of the line strengths for all rotational lines is determined as 2.18×10−15 cm2 cm−1. The band oscillator strength of the e(0,0) band is determined to be (2.47±0.12)×10−3.

The e(1,0) band of NO was measured at high resolution (0.06 cm−1) by the vacuum ultraviolet (VUV) Fourier transform spectrometer from Imperial College, London, using synchrotron radiation at the Photon Factory, KEK, Japan, as a continuum light source. Such resolution facilitates a line by line analysis of the NO e(1,0) band which yields accurate rotational line positions and term values as well as the photoabsorption cross sections. The molecular constants of the D(1) 2 Σ level are found to be T0=55 570.582±0.055 cm−1, Bv=1.979 66±0.000 19 cm−1, Dv=(5.8±4.7)×10−5cm−1, γ=−0.127±0.008 cm−1 and γD=−(1.03±0.04)×10−3 cm−1. The sum of the line strengths for all rotational transitions of the NO e(1,0) band is determined as 2.55×10−15 cm2 cm−1, corresponding to a band oscillator strength of 0.002 88±0.000 17.

Fourier transform spectroscopic measurements of the absorption bands of the Herzberg III (A′ 3Δu–X 3Σg−) of O2 at 295 K have been made with a resolution of 0.06 cm−1 in the wavelength region 240 to 275 nm. Rotational line positions are determined with an accuracy of 0.005 cm−1, and rotational term values are presented for the vibrational levels, v′=4–11. Precise band oscillator strengths of the (4,0)–(11,0) bands are obtained for the first time by direct measurement by summing the cross sections of individual rotational lines of the bands. The rotational line strengths and the branching ratios are also presented for the same bands. The continuity relationship for the band oscillator strengths to photodissociation continuum cross sections has been applied to the three-band systems.

Line-by-line photoabsorption cross-sections of the NO δ(1,0) band were measured with the VUV Fourier transform spectrometer from Imperial College, London, using synchrotron radiation at Photon Factory, KEK, Japan, as a continuum light source. The analysis of the NO δ(1,0) band provides accurate rotational line positions and term values as well as the photoabsorption cross-sections. The molecular constants of the C(1) 2Π level are found to be T0=54 690.155±0.03 cm−1, Bv=1.944 06±0.000 62 cm−1, Dv=(5.91±0.42)×10−5 cm−1, AD=−0.0187±0.0050 cm−1, p=−0.0189±0.0037 cm−1, and q=−0.015 21±0.000 20 cm−1. The sum of the line strengths for all rotational transitions of the NO δ(1,0) band is determined as 4.80×10−15 cm2 cm−1, corresponding to a band oscillator strength of 0.0054±0.0003.

Results are presented of a comparative study in which three distinct high-resolution experimental techniques (vacuum-ultraviolet laser spectroscopy, laser-induced fluorescence spectroscopy and vacuum-ultraviolet Fourier-transform spectroscopy) were used to study predissociation in the Schumann-Runge bands of O2 B 3Σu−(v′)←X 3Σg−(v″) with v′=13 and 14. Our measurements are the first to be performed at high resolution for these levels and represent a significant advance on previous knowledge, characterizing completely the fine-structure and rotation dependencies of the B 3Σu−(v=13 and 14)-state predissociation for the first time. The measured fine-structurespecific linewidths will result in significant improvements in the parameterization of models describing predissociation of the B-state and will have an impact on the development of realistic photochemical models of the terrestrial atmosphere. Good agreement was found between linewidths measured using vacuum-ultraviolet laser spectroscopy and laser-induce...

The platinum isotope anomaly observed in the chemically peculiar HgMn star ? Lupi has been confirmed by analysis with new high-resolution laboratory spectra recorded with the VUV Fourier transform spectrometer at Lund University. The ? Lupi platinum composition is shown to be a mixture of isotopes 196 and 198. Recent observations made with the Hubble Space Telescope Goddard High-Resolution Spectrograph (HST/GHRS) of a similar temperature HgMn star, HR 7775, have also been analyzed; these show that line profiles of Pt II are best fitted by the terrestrial isotopic mixture. Fits of synthetic spectra to the observations yield a logarithmic abundance of platinum of log NPt = +6.05 for ? Lupi and log NPt = +6.50 for HR 7775, on a scale of log NH = +12.00.

The extension to the visible and ultraviolet regions of Fourier transform spectroscopy (FTS), traditionally regarded as a technique for the infrared, has increased the range of its applications to analytical atomic spectroscopy, astrophysics and atmospheric physics. The relative advantages of FTS and grating spectroscopy have to be assessed differently at these shorter wavelengths; it is shown that the very accurate wavenumber scale and the high resolution attainable are usually the most important advantages offered by FTS. The signal-to-noise ratios that can be obtained with the two types of spectrometer with the same source and the same resolution are compared for absorption and emission spectra, and for scanning and multi-channel grating spectrometers. The suitability of FTS for upgrading databases, both for atomic emission spectroscopy and for astrophysical and atmospheric physics applications, is discussed and illustrated with examples of advances made in all these fields.

The joint project between NIST and Imperial College London to measure spectra of singly-ionized iron-group elements using Fourier transform and high-resolution grating spectroscopy is described.

Accurate high resolution atomic and molecular data are required for interpretation of many astrophysical spectra. The Imperial College London laboratory astrophysics program using high resolution Fourier Transform spectrometry is described.

Photoabsorption cross section measurements of the Herzberg I bands (A3Σu+−X3Σg−) of O2 have been made by Fourier transform spectrometry with a resolution of 0.06 cm−1 in the wavelength region 240‐270 nm. Precise band oscillator strengths of the (4,0)–(11,0) bands are obtained by direct measurement, and for some of the strong bands, they are significantly higher than the previous experimental values. The rotational line strengths and the branching ratios are also presented for the same bands. The dissociation energy of O2 is discussed.

Inductively coupled plasma spectra of 33 elements were acquired using a high resolution FT spectrometer in the UV/VIS spectral region. Spectra were recorded from 20000 to 53000 cm −1 (500 to 189 nm) with a resolution of 0.1 cm −1 . From these spectra, a line table with a total number of 2229 lines was compiled listing the wavelength, wavenumber, signal-to-noise ratio and line width of each line. This table is given at the end of the paper. Furthermore, some special features of FT spectra are discussed in comparison to grating spectra.

The combined band oscillator strength of the δ(0,0) and β(7,0) bands of nitric oxide has been measured in absorption by utilizing a vacuum ultraviolet Fourier transform spectrometer to resolve the rotational line profiles. We give accurate rotational line positions of the δ(0,0) and β(7,0) bands, and improved term values up to J=19.5 for the C 2Π(v=0) and J=8.5 for the B 2Π(v=7) levels, measured from the ground state. A deperturbation procedure has been used on the mixed levels, and the calculated molecular constants are in good agreement with previous work.

We report on a series of high resolution molecular spectroscopy measurements performed at Imperial College. We present: the first high resolution measurements of the absorption cross section of the xSO2 (x = 32,33,34 and 36) isotopologues; and completion of a multi-temperature study of the UV spectrum of SO2.

New measurements, by high resolution IR-VUV Fourier Transform spectrometry, of accurate atomic data (wavelengths, energy levels, transition probabilities) for astrophysics applications are presented.

Spectra of nickel, emitted from hollow cathode discharges, have been recorded in the region 1700-55 000 A (58 800-1800 cm−1). Fourier transform spectrometers were used above 1800 A, yielding very high accuracy and resolution. The number of classified Ni I lines has increased from 1071 to 1996. 289 of the lines have been resolved in 2-4 isotope components. The term system derived from the observations comprises 286 energy levels. The term structure and the coupling conditions have been studied by means of ab initio and parametric theory.

The synthesis of some new o-azidodiphenylmethanes 3b, 10, 15, 18, 21 and 22 is described. The first-order kinetics of the thermal decomposition in trichlorobenzene of these and some previously studied azides (3a, 3c and 3d) has been studied in the range 140–180 K. The initial step is evolution of nitrogen and formation of a nitrene intermediate, which reacts to give a 10H-azepinoindole together with some amine. Rate constants for the first step were compared with those for product formation and show it to be the rate-determining factor. Electron-donating substituents para to the azide group stabilise the incipient nitrene by resonance interactions (rate constants correlate with σR+) yielding higher proportions of amine products, which result from the spin forbidden singlet–triplet nitrene transition. Substituents at the 4′-position influence the nature of the products but not decomposition rates. A new compound, 1a-methoxy-1a,9b-dihydro-1H-cyclo-propa[1′,2′:3,4]pyridol[1,2-a]indole (28), is obtained from 2-azido-4′-methoxydiphenylmethane (3d) in addition to the expected azepinoindole and amine. Kinetic measurements show that it is an intermediate in one, but not the sole, route to formation of 8-methoxyazepinoindole 27 from 3d.

Wavelengths and wavenumbers are presented for 290 lines in the spectrum of the Iron-Neon hollow cathode lamp. The lines are all strong, stable, well resolved lines in Fe I or Fe II ; the range covered is from 424 nm to 4.2 μm (23600 to 2354 cm -1 ). The measurements were made by Fourier transform spectrometry with a wavenumber precision of ±0.0003 cm -1 or better. The absolute accuracy, based on visible region Ar II standards, varies from 0.001 cm -1 at 20000 cm -1 to 0.0005 cm -1 at 2300 cm 1- . The absolute scale used is the same as that employed in earlier work, covering the range from 17350 to 55000 cm -1 . The intensities, damping parameters (Lorentzian component of line profile) and observed signal to noise ratios of the lines are also tabulated. Auxiliary experiments showed that lines of large Doppler width or high damping parameter suffer significant wavenumber shifts ; such lines have been excluded from the list. It is also shown that the wavenumbers of unbroadened lines are the same in large (950 mA, 4 mB) and small (20 mA, 10 mB) hollow cathode lamps.

The involvement of Zn2+ in the inhibitory action of insulin and phenformin on bulk proteolysis was studied in the Langendorff rat heart with a Zn(2+)-buffering perfusate (0.1 mM citrate, physiological complete amino acids and 0.2% albumin). Proteins were biosynthetically labeled in vitro for 10 min with [3H]leucine. Rapidly degraded proteins were eliminated during a 3-h preliminary degradation without insulin or added Zn2+ (2 mM nonradioactive leucine). Insulin (5 nM), the lysosomal inhibitor chloroquine (30 μM), and the biguanide antihyperglycemic agent phenformin (2 μm) each caused a sustained 35–40% inhibition of [3H]leucine release beginning within 1–2 min and reaching a maximum at 1–1.5 h. When these agents were combined, their simultaneous proteolytic inhibitory effects were not appreciably > the effect of chloroquine alone. Infusion of supraphysiological perfusate Zn2+ (>15 μM) mimicked the inhibitory effect of insulin and chloroquine on lysosomal proteolysis. Infusion of supraphysiological Co2+, Mn2+, Fe2+, and Cr3+ (30 μM, 0.5 h) caused no change in proteolysis; however, 30 μM Cu2+ caused a slight inhibition. Presumptive chelation of the background (∼20 nM) Zn2+ by infusion of 3 μM CaNa2 EDTA caused no change in protein degradation over 1–2 h. The infusion of a physiological concentration of 1 or 5 microM Zn2+ (as ZnCl2) caused no change in protein degradation over 1–2 h. Biguanides are known to reversibly form a Zn2+ complex with affinity < that of Zn2+ for EDTA. Prior infusion of 3 μM CaNa2 EDTA inactivated the proteolytic inhibitory effect of maximal (2 μM) phenformin over at least 1.25 h of concurrent infusion. restoration of physiological 2 μM Zn2+ immediately restored the insulin-mimetic proteolytic inhibitory action of phenformin under continued 3 μM CaNa2 EDTA (5 μM total Zn2+, 2 μM nonchelated Zn2+). The time course and potency of submaximal insulin (

The wavelengths of the thorium and neodymium lines used in the Butcher stellar chronometer have been remeasured, together with those of weak blended lines of iron and nickel. The results are presented; the absolute accuracy achieved ranges from 0.21 mA for the thorium line to 1.52 mA for the weak iron line. The uncertancy of the wavelengths presented in the literature or deducible from published energy levels is discussed in detail. The database used for astrophysiscs proves to be much older and much less accurate than is often assumed. New instruments, especially Fourier transform spectrometers, offer the possibility of remeasurement to the higher standards needed to interpret current astrophysical observations.

SELEX S&AS is developing a family of infrared sensors for earth observation missions. The spectral bands cover shortwave infrared (SWIR) channels from around 1μm to long-wave infrared (LWIR) channels up to 15μm. Our mercury cadmium telluride (MCT) technology has enabled a sensor array design that can satisfy the requirements of all of the SWIR and medium-wave infrared (MWIR) bands with near-identical arrays. This is made possible by the combination of a set of existing technologies that together enable a high degree of flexibility in the pixel geometry, sensitivity, and photocurrent integration capacity. The solution employs a photodiode array under the control of a readout integrated circuit (ROIC). The ROIC allows flexible geometries and in-pixel redundancy to maximise operability and reliability, by combining the photocurrent from a number of photodiodes into a single pixel. Defective or inoperable diodes (or "sub-pixels") can be deselected with tolerable impact on the overall pixel performance. The arrays will be fabricated using the "loophole" process in MCT grown by liquid-phase epitaxy (LPE). These arrays are inherently robust, offer high quantum efficiencies and have been used in previous space programs. The use of loophole arrays also offers access to SELEX's avalanche photodiode (APD) technology, allowing low-noise, highly uniform gain at the pixel level where photon flux is very low.

High resolution spectrographs on astronomical telescopes create demands for accurate high resolution UV/VUV atomic data for interpretation of astrophysical spectra. Atomic spectroscopy combining high resolution VUV Fourier Transform and grating spectroscopy is described.

Accurate laboratory SO2photoabsorbtion cross sections are essential for the meaningful interpretation of planetary atmospheres. New laboratory measurements of SO2spectra at low temperatures using high resolution VUV Fourier Transform spectroscopy are described.

Photoabsorption measurements of NO bands have been made by vacuum-ultraviolet Fourier transform spectrometry with a resolution of 0.12 cm(-1) in the wavelength region of 166.2-196.2 nm. Accurate line positions are obtained for the delta(upsilon,0) bands with upsilon=2, 3, the epsilon(upsilon,0) bands with upsilon=2, 3, and the beta(upsilon,0) bands with upsilon=10,12,14. Absolute term values are found for the corresponding upper levels C(2,3), D(2,3), and B(10,12,14). Accurate rotational line integrated cross sections have also been obtained for the lines in these bands. Integrated cross sections reported in our earlier papers [J. Chem. Phys. 109, 1751 (1998); 112, 2251 (2000); 115, 3719 (2001); 116, 155 (2002); 117, 10621 (2002); 119, 8373 (2003)] have been revised, and the results reported here comprise the delta(upsilon,0) bands with upsilon=0-3, the epsilon(upsilon,0) bands with upsilon=0-3, the beta(upsilon,0) bands with upsilon=6,7,9-12,14, and the gamma(3,0) band. For each band, the band oscillator strength is obtained from the sum of the line strengths of all rotational lines, and these are compared with other published values.

Accurate new high-resolution UV and VUV atomic and molecular data for astrophysics and atmospheric physics are needed. Extension of Fourier transform spectroscopy into the VUV at Imperial College is outlined, and laboratory spectroscopy applications described.

We report on recent measurements at Imperial College using our high resolution VUV Fourier Transform Spectrometer to study atomic and molecular spectra relevant to astrophysics and atmospheric physics.

High resolution studies using Fourier transform spectrometry of the spectra emitted in the visible and ultraviolet regions by a microwave boosted glow discharge source have shown that when the source is operated in the dc (unboosted) mode, two anomalous forms of line profile occur for some analyte elements. (1) Some Fe I lines appear to have a triangular base of half-width about five times greater than that of the line proper. (2) Some Fe II and Ti II lines exhibit satellites about 8 cm(-1) wide and an intensity of up to 2% of the peak value on either side of the main line. Both effects depend on the carrier gas and its pressure and are much less pronounced or even absent in the boosted mode. They could both affect the accuracy of analytical results, particularly for depth-profiling. Further studies are in progress.

The relative advantages of Fourier transform and grating spectrometry in the visible and ultraviolet regions for the particular purposes of wavelength, width standard and intensity calibration are compared. The results of some feasibility studies on McCrone wavelength standards and on different standard lamps are discussed. Finally, some thoughts on the future prospects for FTS in this field are presented.

Fourier transform spectroscopy (FTS) combines the advantages of high resolution (sufficient to resolve Doppler line widths) with large optical throughput and an accurately linear wavenumber scale. The resolving power of about a million required for studies of atoms or molecules at 300 K has previously been achieved with the Imperial College FT spectrometer for VUV wavelengths down to 178 nm, the cut-off of the silica beamsplitter. This beamsplitter has a unique configuration, designed to ensure alignment at short wavelengths. We have now extended the wavelength range further into the VUV by replacing it with a similar beamsplitter made from a single MgF2 crystal. The performance of the spectrometer with the new beamsplitter has been evaluated, and emission spectra from hollow cathode lamps have been recorded down to about 150 nm with a resolution of 0.08 cm-1, representing a resolving power of 850,000.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Four distinct processes mediating protein degradation were identified in the Langendorff perfused rat heart. Hearts were biosynthetically labeled in vitro with [3H]leucine for 10 min. The subsequent release of [3H]leucine at 1.5-min intervals (2 mM nonradioactive leucine) was determined from 20 min to 8 h after labeling in rhythmically contracting hearts. Rapid turnover proteins were eliminated during the first 3 h; this degradation was not inhibited by insulin (5 nM) or isoproterenol (0.5 microM). However, the nontoxic thiol reactive agent diamide (100 microM) caused a complete inhibition of the [3H]leucine release from rapidly degraded proteins. After the elimination of rapidly degraded proteins at 3 h, the release of [3H]leucine was inhibited 35-40% by insulin (5 nM) or the lysosomal inhibitor chloroquine (30 microM), thereby defining a second vesicular process. The beta-agonist isoproterenol (0.5 microM) or the nonselective alpha-agonist naphazoline (100 microM) caused 30-35% proteolytic inhibitions, defining a third adrenergic-responsive process. The inhibitory effects of simultaneously combined insulin and chloroquine did not exceed the effect of either agent alone. However, the combined effects of insulin and isoproterenol were additive, inhibiting two-thirds of basal degradation. Beginning at 3 h after labeling a 75% proteolytic inhibition resulted from the thiol reactive agents diamide (100 microM) or N-ethylmaleimide (10 microM); the thiol protease active site inhibitor trans-epoxysuccinly-L-leucylamino-(4-quinidino)butane (50 microM) caused 65% inhibition. The 75% inhibition caused by diamide includes both the insulin-responsive and beta-adrenergic-responsive pathways. A novel fourth proteolytic process (25% of proteolysis) was thereby distinguished from the above three by its resistance to inhibition by insulin, adrenergic agonists, thiol reactive agents, or thiol protease inhibitor. Only the adrenergic-responsive process was correlated with changes in contractile rhythm or fibrillation.

The spectrum and extended term analysis of V II are presented. Fourier transform spectrometry was used to record high resolution spectra of singly ionized vanadium in the region 1492-5800 A (67020-17260 cm–1) with vanadium-neon and vanadium-argon hollow cathode lamps as sources. The wavenumber uncertainty for the center of gravity of the strongest lines is typically 0.002 cm–1, an improvement of an order of magnitude over previous measurements. Most of the lines exhibit partly resolved hyperfine structure. The V II energy levels in the 1985 compilation of Sugar and Corliss have been confirmed and revised, with the exception of the high-lying 4f levels and eight of the lower levels. Thirty-nine of the additional eighty-five high levels published by Iglesias et al. have also been confirmed and revised, and three of their missing levels have been found. The energy uncertainty of the revised levels has been reduced by about an order of magnitude. In total, 176 even levels and 233 odd levels are presented. Wavenumbers and classifications are given for 1242 V II lines.

Current work with the visible-UV FT spectrometer at Imperial College is directed at improving the data base for the astrophysically and analytically important transition elements, using complementary data from the IR obtained at the National Solar Observatory, starting with iron, chromium and cobalt. This paper highlights the gains and problems of FTS for this type of work.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Pathways of bulk protein degradation controlled by insulin and isoprenaline (isoproterenol) were distinguished in Langendorff-perfused rat hearts. Proteins were biosynthetically labelled in vitro with [3H]leucine, followed by addition of 2 mM non-radioactive leucine to competitively prevent reincorporation. Rapidly degraded proteins were eliminated during a 3 h preliminary perfusion period without insulin. One third of bulk myocardial protein degradation was inhibited by isoprenaline as described previously. An insulin concentration of 5 nM maximally inhibited proteolysis, beginning within 2 min. Inhibition reached 32% within 1.25 h and 35% after 1.5 h. The minimum effective insulin concentration was approx. 10-50 pM, which caused 10-20% inhibition. Following 3 h of perfusion without insulin, the lysosomal inhibitor, chloroquine (30 microM), inhibited 38% of bulk degradation. The 35% proteolytic inhibition caused by insulin was followed by very little further inhibition on subsequent concurrent infusion of chloroquine, i.e. the inhibitory effects of insulin and chloroquine were not additive. In contrast, prior inhibition of lysosomal proteolysis by insulin or chloroquine did not prevent the subsequent additive inhibition caused by isoprenaline. Insulin and beta-agonists additively inhibited approx. two-thirds of bulk degradation. The biguanide antihyperglycaemic agent phenformin (2 microM) inhibited 35% of bulk degradation, beginning at 2 min and reaching a near maximum at approx. 1.25-1.5 h. Following inhibition of proteolysis with phenformin (20 microM), subsequent infusion of chloroquine (30 microM) produced only a slight additional inhibition. Following inhibition of 35% of degradation by 1.5 h of perfusion with insulin (5 nM), subsequent exposure to phenformin (2 microM) produced only a slight additional inhibition which did not exceed 38% of basal proteolysis. Thus insulin and phenformin both inhibit lysosomal proteolysis; however, the adrenergic-responsive pathway is distinct.

We describe an optimized microarray method for identifying genome-wide CpG island methylation called microarray-based methylation assessment of single samples (MMASS) which directly compares methylated to unmethylated sequences within a single sample. To improve previous methods we used bioinformatic analysis to predict an optimized combination of methylation-sensitive enzymes that had the highest utility for CpG-island probes and different methods to produce unmethylated representations of test DNA for more sensitive detection of differential methylation by hybridization. Subtraction or methylation-dependent digestion with McrBC was used with optimized (MMASS-v2) or previously described (MMASS-v1, MMASS-sub) methylation-sensitive enzyme combinations and compared with a published McrBC method. Comparison was performed using DNA from the cell line HCT116. We show that the distribution of methylation microarray data is inherently skewed and requires exogenous spiked controls for normalization and that analysis of digestion of methylated and unmethylated control sequences together with linear fit models of replicate data showed superior statistical power for the MMASS-v2 method. Comparison with previous methylation data for HCT116 and validation of CpG islands from PXMP4, SFRP2, DCC, RARB and TSEN2 confirmed the accuracy of MMASS-v2 results. The MMASS-v2 method offers improved sensitivity and statistical power for high-throughput microarray identification of differential methylation.

The β(6,0) (B 2Πr–X 2Πr) and γ(3,0) (A 2Σ+–X 2Πr) bands of NO have been recorded using a vacuum ultraviolet Fourier transform spectrometer with synchrotron radiation as light source. The analysis of the β(6,0) and γ(3,0) bands of NO provides accurate rotational line positions and term values. Molecular constants of the v=6 level of the B 2Πr and v=3 level of the A 2Σ+ have been determined. Accurate rotational line strengths have also been obtained. The band oscillator strength of the β(6,0) and γ(3,0) bands are determined to be 0.48×10−4 and 2.69×10−4, respectively.

A high-resolution ultraviolet–visible Fourier transform spectrometer has been used to record spectra from a Grimm-type glow discharge source with and without supplementary microwave excitation. Various cathodes were used (copper, aluminium, iron and chromium) with argon or neon as the carrier gas. True line profiles were recorded directly, so that line shapes could be studied easily. Close lines could be distinguished and identifications made unambiguously, even when major changes in relative intensities occurred. In this paper, information is presented on the effects of the excitation conditions on the iron and chromium spectra, using relative intensity measurements on a very large number of spectral lines. The results emphasize that any ‘excitation temperatures’ deduced from data on a limited number of lines are meaningless. The contribution of charge exchange processes to the excitation of ionic lines is discussed in detail. Line profile measurements will be reported in a subsequent paper.

The synthesis of some new o-azidodiphenylmethanes 3b, 10, 15, 18, 21 and 22 is described. The first-order kinetics of the thermal decomposition in trichlorobenzene of these and some previously studied azides (3a, 3c and 3d) has been studied in the range 140–180 K. The initial step is evolution of nitrogen and formation of a nitrene intermediate, which reacts to give a 10H-azepinoindole together with some amine. Rate constants for the first step were compared with those for product formation and show it to be the rate-determining factor. Electron-donating substituents para to the azide group stabilise the incipient nitrene by resonance interactions (rate constants correlate with σR+) yielding higher proportions of amine products, which result from the spin forbidden singlet–triplet nitrene transition. Substituents at the 4′-position influence the nature of the products but not decomposition rates. A new compound, 1a-methoxy-1a,9b-dihydro-1H-cyclo-propa[1′,2′:3,4]pyridol[1,2-a]indole (28), is obtained from 2-azido-4′-methoxydiphenylmethane (3d) in addition to the expected azepinoindole and amine. Kinetic measurements show that it is an intermediate in one, but not the sole, route to formation of 8-methoxyazepinoindole 27 from 3d.

The wave numbers of 167 Fe i lines between 26 000 and 34 100 cm−1 (385–293 nm), 146 Fe i lines between 33 700 and 51 400 cm−1 (297–195 nm), and 221 Fe ii lines between 35 900 and 54 600 cm−1 (279–183 nm) are measured with a relative precision of 30 parts in 109 by Fourier-transform spectrometry. Bridging techniques are used to place the measurements on the same Ar ii–based absolute wave-number scale as previously measured visible spectra. The uncertainty in the absolute wavelengths is limited by small source shifts and the accuracy of the available standards and is estimated to be 0.002 cm−1 (0.008 pm at 200 nm). This is an order of magnitude better than that of the majority of current UV standards.

The extension of high resolution FTS into the ultra-violet (λ≥175 nm) is described briefly and illustrated by two applications. In the hollow cathode spectrum of iron, wavelength measurements have been made with an accuracy from 1∶109 in the visible to 1∶108 in the UV. In atomic emission spectroscopy with ICP or glow discharges, full spectral information, with completely resolved line profiles, is obtained.

Organo-tin catalysts have been used to prepare a large number of new carbamates of tertiary alcohols. Cyclization of carbamates of unsaturated tertiary alcohols leads to the formation of 2-oxazolidinones, and provides a new synthetic route for some of these compounds.