bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and characterization of hyaluronan/chitosan scaffold cross‐ linked by 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide
Authors: Deng Yu , Liu Dengru , Du Guocheng , Li Xiufen , Chen Jian 
Published: February 2007

AbstractA novel biocompatible scaffold was prepared by cross‐linking hyaluronan (HA) and chitosan (CS). The carboxyl groups of HA were activated by 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide (EDC) and then cross‐linked with amino groups of CS by forming amide bonds. The HA/CS scaffold thus prepared was characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and differential scanning calorimetry. FTIR spectra showed that the absorbance of the amide (1550 cm−1) and carbonyl (1633 cm−1) bond in the cross‐linked scaffold was stronger than that in HA or CS. SEM micrographs showed that the cross‐linked scaffold produced at low EDC concentration had an intertwisted ribbon‐like microstructure, while the product prepared at higher EDC concentration had a porous structure. The concentration of EDC in the reaction system greatly affected the structure and properties of the HA/CS scaffold. The prepared scaffold could strongly resist degradation by hyaluronidase, free radicals in vitro and stress. Copyright © 2007 Society of Chemical Industry
Vitamin E succinate inhibits NF‐κB and prevents the development of a metastatic phenotype in prostate cancer cells: Implications for chemoprevention
Authors: Crispen Paul L. , Uzzo Robert G. , Golovine Konstantin , Makhov Peter , Pollack Alan , Horwitz Eric M. , Greenberg Richard E. , Kolenko Vladimir M. 
Published: February 2007

AbstractBACKGROUNDNF‐κB and AP‐1 transcriptional factors contribute to the development and progression of prostate malignancy by regulating the expression of genes involved in proliferation, apoptosis, angiogenesis, and metastasis.METHODSNF‐κB and AP‐1 activities were examined by TransAm assay. Cytokines levels were assessed by ELISA. ICAM‐1 and gp130 expression was examined by flow cytometry. Cell adhesion was examined by the ability of cells to adhere to fibronectin‐coated plates. Cell viability was determined by propidium iodide staining.RESULTSTreatment with α‐tocopherol succinate (VES) inhibits NF‐κB but augments AP‐1 activity, reduces expression of IL‐6, IL‐8, and VEGF, suppresses cell adhesion, ICAM‐1 and gp130 expression in androgen‐independent PC‐3, DU‐145, and CA‐HPV‐10 cells. VES supplementation also decreases the expression of anti‐apoptotic XIAP and Bcl‐XL proteins and sensitizes androgen‐dependent LNCaP cells to androgen deprivation.CONCLUSIONSOur findings propose a potential mechanism of VES‐mediated anti‐tumor activity and support the role of vitamin E analogs as potential chemopreventative agents against prostate cancer. Prostate 67: 582–590, 2007. © 2007 Wiley‐Liss, Inc.
The Design and Evaluation of Placebo Material for Crude Herbals: Artemisia afra Herb as a Model
Authors: Dube A. , Manthata L. N. , Syce J. A. 
Published: February 2007

AbstractHerbal materials are known to present significant challenges with regard to designing credible placebos. This study intended to demonstrate the possibility of designing placebo material for crude herbals and used Artemisia afra, a popular traditional herbal medicine in South Africa, as a model. To produce the placebo, step‐wise solvent extractions were conducted on the plant leaves and the process was monitored spectrophotometrically and using high performance liquid chromatography (HPLC) with diode array detection. The odour and taste between the placebo and A. afra was matched by inclusion of linalool and sodium saccharin, respectively. The muscle relaxant activity of the placebo was evaluated using an isolated guinea‐pig tracheal muscle preparation. The UV absorbance of the extracts and the HPLC chromatograms, showed that most of the phytochemical constituents had been removed and the placebo closely resembled the A. afra leaves. The EC50 of the placebo and the leaves were 4846.00 and 68.49 mg/mL, respectively, which showed that not only did the A. afra leaves possess muscle relaxant activity, but that the placebo did not possess any significant activity compared with the A. afra leaves (p value 0.0001). These results demonstrated that it is possible to design credible, pharmacologically inert placebo material for crude herbals. Copyright © 2007 John Wiley & Sons, Ltd.
The structure of the intertropical front over N.W. India during the S.W. Monsoon
Authors: Sawyer J. S. 
Published: February 2007

AbstractThis paper investigates the structure of the intertropical front over N.W. India by means of the daily radio‐sonde and meteorological flight observations made during ten days of undisturbed weather during the monsoon of 1945. The conclusions are incorporated in the schematic cross sections (Figs. 12 and 13).In the course of the investigation it is found that the winds in the continental air are notably sub‐geostrophic. No explanation of this is given.
Evaporation from extensive surfaces of water roughened by waves
Authors: Norris Ramalingam 
Published: February 2007

AbstractThe problem of evaporation from large expanses of water is of fundamental importance. The evaporation from oceans is of importance in studying the amount of water vapour which an air mass receives while flowing over the ocean. Among recent investigations on the problem of evaporation may be mentioned in particular those of Sverdrup (1936), Millar (1937), and Montgomery (1940). But the final conclusive results of these authors differ very much from each other. For instance, Sverdrup (1937–8) concludes that the evaporation from a hydrodynamically rough surface must be twice as great as that from a smooth surface, while Montgomery infers it to be about the same in both cases. The question is reconsidered below, the work of these authors being followed to a certain extent, but not entirely. The differences are emphasised wherever necessary. The present investigation leads to the result that the evaporation from a hydrodynamically rough surface must be about four times as great as that to be expected from a smooth surface of water.
The effect of freezing and melting processes on the daily temperature curve at quebec city
Authors: Longley Richmond W. 
Published: February 2007

AbstractA study was made of the frequency distribution of the daily maximum and minimum temperatures for the city of Quebec for the periods 1 February to 31 May and 1 September to 31 December. It was discovered that during the period when the snow was melting there was a damping effect of approximately 2°F on the maximum temperature on those days when the temperature rose above freezing. After the snow disappeared and the ground thawed out, there was a corresponding damping of about 1°F on the minimum temperature on those days when it approached freezing. The damping effect in the autumn is less than 1°F. Other features of these frequency distributions are also brought out.
Physical interactions between tropical and temperate latitudes
Authors: Priestley C. H. B. 
Published: February 2007

AbstractThe poleward transports of momentum and angular momentum, enthalpy, water vapour, and total energy are studied at a number of upper‐air stations in the high‐pressure belt. The results confirm earlier suggestions of a mean meridional circulation across this belt; this circulation is found to contribute about one half the total poleward transport of both energy and angular momentum, and also to make a substantial contribution to the maintenance of the total kinetic energy of the atmosphere. The meridional circulation appears notably stronger in winter than in summer. The poleward transport of angular momentum to the Westerlies reflects this variation, whereas there is relatively little seasonal variation in the contribution from eddy flux (horizontal rotations) or in the total generation of angular momentum in the Easterlies of low latitudes.Variations of eddy flux with height are examined and certain general features (Priestley, Q.J., 1949) confirmed. The lowest 500 mb of atmosphere make no appreciable contribution to the net eddy flow of momentum, the transport occurring mainly at the 300 mb and 200 mb levels.The results also provide a measure of the difference between total annual precipitation and evaporation in the tropical zone.
Observations with a directional raingauge
Authors: Lacy R. E. 
Published: February 2007

AbstractAn octagonal raingauge, which was set up to study the way in which rain impinged on vertical surfaces, is described. Observations made over a period of 12 years are analysed, showing that, in the London area, walls with moderate exposure to wind and facing approximately SW. receive most rain, equivalent to about 1/4 of the normal rainfall, and walls facing N. receive least, about 1/16 the normal rainfall. An equation connecting the mean incident angle of the rain on the ground with the wind speed is derived, and an attempt is made to obtain an indication of raindrop diameter.
Drop‐size distribution in cloud and fog
Authors: Best A. C. 
Published: February 2007

AbstractExperimental data relating to drop‐size distribution in cloud and fog are examined and it is shown that in many cases the size distribution can be represented by the formula

where F is the fraction of liquid water in the air comprised by drops with diameter less than x. The constant a increases with the liquid water content of the cloud. It is not clear what governs the value of the constant n but a reasonable mean value is about 3.3.It is shown that, if the drop‐size distribution can be described by the equation quoted above the median volume diameter is the most suitable parameter for describing the average size of the cloud particles when the value of n is not known.
The relation between thickness of cloud layers and their transmission of light
Authors: Atkins W. R. G. 
Published: February 2007

AbstractApparent minimal cloud‐transmission percentages for Bircham Newton are plotted against vertical distribution of clouds observed by aircraft, and cloud amount. With under 20 per cent transmission great cloud thickness is possible, but with over 30 per cent no great thickness of low cloud occurs. Percentage frequencies of minimal cloud transmission are given for a year.
On the propagation and growth of jet‐stream waves
Authors: Petterssen Sverre 
Published: February 2007

AbstractOn the assumption of adiabatic and frictionless motion general expressions for the rates of propagation and growth of wave‐shaped circulation patterns are derived, allowing the wind field to possess such general characteristics as vertical velocity, lateral shear, divergence, etc. The general equations are specialized to apply to sinusoidal wave models resembling the type of waves that occur in connection with strong concentrated currents (e.g., the jet stream) in the middle and upper troposphere in middle latitudes. It is shown that the rate of propagation of these waves is determined primarily by the wind speed, the wave length, the ‘width’ of the current, and the meridional variation of the Coriolis parameter while the Coriolis parameter itself is relatively unimportant. It is shown that the growth rate is determined primarily by the meridional variation of the Coriolis parameter and the orientation of the troughs and wedges relative to the meridians. Some comments are offered on the propagation of jet‐stream waves associated with ocean currents.
A cloud‐droplet sampler for use on aircraft
Authors: Squires P. , Gillespie C. A. 
Published: February 2007

AbstractAn instrument is described with which cloud‐droplet samples can be taken from an aircraft by exposing momentarily glass rods coated with magnesium oxide. Exposures can be repeated about every three seconds. (i.e., about every 200 m). The spectra found in a traverse through a cumulus are shown.Features of the distribution of spectra can be determined which could not readily be found by methods which average over some distance, or by sampling methods not capable of being repeated so often. The samples are too widely spaced, however, to yield a coherent sequence of spectra across a cumulus.
Schemes for the study of hemispheric exchange processes
Authors: Starr V. P. , White R. M. 
Published: February 2007

AbstractTwo alternative existing schemes for the classification of eddy‐exchange processes are examined. It appears that each scheme is adapted to the study of distinct physical questions concerning the atmosphere. Hemispheric wind data are used to illustrate the inherent differences of the two methods.A relatively high positive spatial correlation is found between the eastward and northward components of the mean vector wind along the latitude circle in the vicinity of 30°N. at the level of the jet stream.
Measurements of condensation nuclei over the North Atlantic
Authors: Moore D. J. 
Published: February 2007

AbstractMeasurements of the total concentration of condensation nuclei and of the concentration and size distribution of large sea‐salt nuclei have been made on board an Ocean Weather Ship in the North Atlantic over a period of three weeks. Total nucleus counts varied between 77/cm3 and 2,460/cm3, the numbers decreasing with increase in the intensity of vertical mixing as indicated by cloud type.The concentration of large nuclei (mass > 10−11 g) was found to increase markedly with wind speed and wave height, but no corresponding increase was found for the total nucleus population.An analysis of the visibility observations at the Ocean Weather Ship Stations ‘Item’ and ‘Jig’ shows that the opacity for a given humidity increases with wind speed and wave height and that this increase can be accounted for by the observed increase in the concentration of large nuclei.Consequently if the rate of production of small nuclei at the sea surface increases with wind speed, such increase (for wind speeds up to 18 m/sec) does not materially affect the total nucleus population a few metres above the surface.
Note on the structure of the high altitude strong‐wind belt in the Middle East in winter
Authors: Bannon J. K. 
Published: February 2007

AbstractBy referring the upper‐air observations at Habbaniya and Bahrein for January 1951 to the estimated central axis of the strong stream a meridional cross‐section is constructed showing the mean structure for that month of the strong‐wind belt in the upper troposphere over Iraq. This mean structure should apply to the stream on a particular day in contrast to the mean flow as usually computed which shows the average conditions above each observing station. The stream is found to be broad and without strong horizontal gradients. Its axis is at about 190 mb, its mean position about 32°N and the breadth of the region of highest speeds (100 kt or more) about 800 mi.
A sensitive recording dew‐balance
Authors: Jennings E. G. , Monteith J. L. 
Published: February 2007

AbstractThe instrument described gives a continuous record on photographic paper of the change in weight of a naturally exposed grass surface, 330 cm2 in area. The sensitivity is 2 mg cm−1 per cm of record and the time scale is 0.5 hr/cm. Observations suggest that on very calm nights the condensation of vapour reaching the surface by diffusion from the atmosphere is only a small fraction of the total ‘dew.’ The maximum rate of deposition that has been observed on short grass is 0.03 mm hr−1.
Air pollution aspects of the London fog of December 1952
Authors: Wilkins E. T. 
Published: February 2007

AbstractThis four‐day fog caused at least 4,000 deaths and much illness; it therefore ranks as the most disastrous event of its kind known to have occurred anywhere in the world. For the first time in an incident of this kind extensive measurements were made of the daily concentrations of smoke and sulphur dioxide and of the general pattern of pollution throughout the area.Mean concentrations of smoke and sulphur dioxide at 12 daily test‐sites increased sharply on the first day of the incident and, after 3 to 4 days, averaged 1.6 mg/m3 and 0.7 parts per million respectively, or about 5 to 6 times normal. At individual sites in the central London area concentrations rose to 10 times normal.There was a striking parallelism between the mean daily concentration of smoke and sulphur dioxide and the total number of deaths on those days but the latter returned the more slowly to normal.A few data, relating to a severe London fog of 1948, indicated that the concentrations of pollution then reached about 50 to 70 per cent of the 1952 values.The approximate distribution of sulphur dioxide is shown on a map which indicates zones of maximum pollution mainly in the riverside areas, and particularly Westminster and adjacent boroughs.
Five flights through a thunderstorm belt
Authors: Jones R. F. 
Published: February 2007

AbstractAnalysis of accelerometer and other aircraft‐instrument records taken on five flights through thunderstorms shows that it is possible to obtain the detailed structure of the vertical air currents within the clouds. A feature of the clouds studied was the close proximity of upward and downward air currents of comparable magnitude, exceeding 20 ft/sec on occasions. Frequency and intensity of gusts increased markedly on entry into cloud and correlation with the radar echo received from the storms showed that all the biggest gusts were recorded within the echoing volume. On four out of five occasions when lightning was seen the aircraft was not in any appreciable upward or downward current, and on all five occasions the cloud had already attained its maximum development.
A note on computed transports of angular momentum in a theoretical model of the general circulation
Authors: Rogers M. H. 
Published: February 2007

AbstractAngular momentum transports due to mean meridional circulations and horizontal exchange processes are computed for a theoretical model. It is found that, in high latitudes, the transport due to mean meridional circulations is less than 1 per cent of that due to horizontal exchange processes. In the tropics, however, the transport due to mean meridional circulations is seen to dominate that due to horizontal exchange processes. It is suggested that a variable coefficient of eddy viscosity would have to be used in order to explain observed motions on a synoptic scale.
Some aspects of the variability of annual rainfall over the British Isles for the standard period 1901–30
Authors: Gregory S. 
Published: February 2007

AbstractAlthough the map of mean annual rainfall in the Climatological Atlas of the British Isles is for the period 1901–30, those maps which illustrate aspects of the variability of annual rainfall have not been presented for the same period. In this paper, the relative variability for the standard period 1901–30 is mapped and examined, and compared with the 1881–1915 pattern. This is followed by a brief commentary on the distribution of years of highest and lowest rainfall, the percentage relationship between these extreme values and the average, and the extreme variability of the annual rainfall, all these also being for the period 1901–30.
Some recent measurements of humidity from aircraft up to heights of about 50,000 ft over southern England
Authors: Murgatroyd R. J. , Goldsmith P. , Hollings W. E. H. 
Published: February 2007

AbstractThe humidity of the air was measured with a pressurized Dobson‐Brewer hygrometer in a Canberra aircraft up to heights of about 50,000 ft over southern England on 35 occasions during 1954. The frost point decreased with increasing height in the stratosphere and usually approached a constant value of − 115°F to − 120°F a few thousand feet above the tropopause.
Preliminary studies of the distribution of particles at medium range from a ground‐level point source
Authors: Pasquill F. 
Published: February 2007

AbstractAs a basis for planning a comprehensive study of the diffusion of airborne material over distances up to 100 mi a small number of exploratory experiments was carried out during February‐April 1955, using as a tracer a fluorescent pigment similar to that described by Braham et al. in Trans. Amer. Geophys. Un., December 1952. Samples were taken at distances up to 40 mi downwind of a ground‐level source and at heights up to 4,000 ft, using an impactor with a receiving surface in the form of a drum, the instrument being carried across the cloud in a Land‐Rover and a Hastings aircraft of the Meteorological Office Research Flight based at R.A.E., Farnborough.The direction and speed of travel of the clouds were on the average closely in accordance with the measured vector mean wind over the first 2,000 or 3,000 ft, individual deviations therefrom being ± 5° in direction and ± 4 mi hr−1 in speed.The conditions were mainly moderately unstable in the lower layers with overhead inversions at heights ranging from 2,000 to 7,500 ft. Effective extreme cloud widths ranged from about 40° (angle subtended at source) at 5 mi to about 20° at 40 mi. Vertical diffusion in the layer between the ground and the inversion appeared to be an order of magnitude more rapid than in the lower atmosphere in neutral conditions of stability. No decisive evidence was found as regards the effect of an overhead inversion in limiting the extent of vertical diffusion.The difficulties encountered in obtaining and interpreting the distribution downwind of a source of short duration emphasize that it would be more profitable to use a longer duration source and to carry out the sampling operations away from the leading and trailing edges of the cloud.
Airflow over mountains: The lee‐wave amplitude
Authors: Corby G. A. , Wallington C. E. 
Published: February 2007

AbstractAlthough orographic lee waves are probably common over the British Isles, their amplitude is so critically dependent on airstream characteristics and on the scale of local topography that they are likely to be insignificant unless a variety of conditions is satisfied. Precise criteria for large‐amplitude waves cannot be formulated for airstreams in general, but simplification of the general problem illustrates the pronounced effect of mountain size and shape, stability and wind speed on the lee‐wave amplitude.
The decay of the ice‐nucleating properties of silver iodide released from a mountain top
Authors: Smith E. J. , Heffernan K. J. 
Published: February 2007

AbstractSilver‐iodide freezing nuclei, together with a tracer of zinc‐sulphide particles, were released from a mountain top and detected in an aircraft. The ice‐nucleating properties of the silver iodide decayed in the daytime but not at night. The ambient temperature did not appear to affect the daytime rate of decay. The top of the smoke plume rose no higher than in previous experiments when it was released from a flat plain.
Temperature differences in the South Tyne Valley, with special reference to the effects of air mass
Authors: Richardson W. E. 
Published: February 2007

AbstractObservations at three stations have been analysed to determine the teperature profile of a N‐S valley. The relationships between them have been classified, their frequencies tabulated, and further analyses undertaken linking these relationships to air‐mass types. An attempt has been made to correct the observed values for the period under review (October 1952 to May 1954) to the twelve years' basis used by Belasco for his work on air‐mass frequency. It is concluded that air‐mass properties have an effect upon the relationships other than those resulting from differences of wind speed and direction, radiation, and insolation.