bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanoparticle characterization by continuous contrast variation in small-angle X-ray scattering with a solvent density gradient
Authors: Garcia-Diez Raul , Gollwitzer Christian , Krumrey Michael
Published: December 2014

Many low-density nanoparticles show a radial inner structure. This work proposes a novel approach to contrast variation with small-angle X-ray scattering based on the constitution of a solvent density gradient in a glass capillary in order to resolve this internal morphology. Scattering curves of a polymeric core–shell colloid were recorded at different suspending medium contrasts at the four-crystal monochromator beamline of PTB at the synchrotron radiation facility BESSY II. The mean size and size distribution of the particles as well as an insight into the colloid electron density composition were determined using the position of the isoscattering points in the Fourier region of the scattering curves and by examining the Guinier region in detail. These results were corroborated with a model fit to the experimental data, which provided complementary information about the inner electron density distribution of the suspended nanoparticles.
Ultra-small-angle X-ray scattering study of second-phase particles in heat-treated Zircaloy-4
Authors: Srirangam Prakash , Idrees Yasir , Ilavsky Jan , Daymond Mark R.
Published: December 2014

The ultra-small-angle X-ray scattering (USAXS) technique has been used to investigate and to quantify the morphology and size distribution of second-phase particles in Zircaloy-4 under various heat-treatment conditions. The alloy samples were solutionized in the β phase field at 1293 K for 15 min and then cooled at different rates, including water quenching, air cooling and furnace cooling. The water-quenched samples were subsequently subjected to a thermal aging treatment at 873 K for different aging times (30, 60, 120 and 300 min). The USAXS results show that water quenching and air cooling from the β phase field produces a narrow size distribution of fine-size precipitates with an average diameter of 300–800 Å, while furnace cooling resulted in coarsening of the particles, with a broad size distribution having an average precipitate size of 600–1200 Å. Further, the furnace-cooled sample shows a higher volume fraction of particles than the water-quenched or air-cooled sample. The USAXS results on the quenched then aged samples show that aging at 873 K for 10 min resulted in very fine size precipitates with an average diameter of 200–350 Å. A rapid precipitation with the highest number density of second-phase particles amongst all the heat-treated samples (4.3 × 1020 m−3) was observed in the sample aged for 10 min at 873 K. Particles of larger size and with a broad size distribution were observed in the sample aged at 873 K for 300 min. A bimodal type of particle size distribution was observed in all the heat-treated samples. Important parameters in the characterization of second-phase particles, such as the average size, size distribution, volume fraction and number density, were evaluated and quantified. These parameters are discussed for both β heat-treated and aged specimens. Transmission and scanning transmission electron microscopy characterization were carried out on all heat-treated samples, to assist in interpretation and to substantiate the results from the USAXS measurements.
KWS-1 high-resolution small-angle neutron scattering instrument at JCNS: current state
Authors: Feoktystov Artem V. , Frielinghaus Henrich , Di Zhenyu , Jaksch Sebastian , Pipich Vitaliy , Appavou Marie-Sousai , Babcock Earl , Hanslik Romuald , Engels Ralf , Kemmerling Günther , Kleines Harald , Ioffe Alexander , Richter Dieter , Brückel Thomas
Published: December 2014

The KWS-1 small-angle neutron scattering (SANS) instrument operated by the Jülich Centre for Neutron Science (JCNS) at the research reactor FRM II of the Heinz Maier-Leibnitz Zentrum in Garching near Munich has been recently upgraded. The KWS-1 instrument was updated, from its active collimation apertures to the detector cabling. Most of the parts of the instrument were installed for the first time, including a broadband polarizer, a large-cross-section radio-frequency spin flipper, a chopper and neutron lenses. A custom-designed hexapod in the sample position allows heavy loads and precise sample positioning in the beam for conventional SANS experiments as well as for grazing-incidence SANS under applied magnetic field. With the foreseenin situpolarization analysis the main scientific topic of the instrument tends towards magnetism. The performance of the polarizer and flipper was checked with a polarized3He cell at the sample position. The results of these checks and a comparison of test measurements on a ferrofluid in a magnetic field with polarized and nonpolarized neutrons are presented.
An X-ray diffractometer using mirage diffraction. Erratum
Authors: Fukamachi Tomoe , Jongsukswat Sukswat , Ju Dongying , Negishi Riichirou , Hirano Keiichi , Kawamura Takaaki
Published: December 2014

Errors in the article by Fukamachi, Jongsukswat, Ju, Negishi, Hirano & Kawamura [J. Appl. Cryst.(2014),47, 1267–1272] are corrected.
An optical chopper for generation of short X-ray pulses to allow in-house time-resolved photocrystallography. Corrigendum
Authors: Kamiński Radosław , Benedict Jason B. , Nottingham Gary , Coppens Philip
Published: December 2014

In the paper by Kamińskiet al.[J. Appl. Cryst.(2014),47, 1765–1768], Jason B. Benedict is missing from the list of authors. The complete list of authors should be Radosław Kamiński, Jason B. Benedict, Gary Nottingham and Philip Coppens.
Constitutional Change inEngland and the Diffusion of Regulatory Initiative, 1660–1714
Authors: Pettigrew William A.
Published: December 2014

This article places a new account of theEnglish state's changing framework for economic regulation alongside what economic historians have demonstrated about the phasing and arenas of economic growth between 1660 and 1714. It places studies of parliamentary legislation into a broader examination of the state's means of regulation (which included the privy council and parliament) and sets this account of regulatory actions against a new account of the changing ways in which petitions approached the state as a regulatory body and how the state responded to those approaches. It also offers a more textured account of the changing styles of economic regulation in this period and of the important (though neglected) role played by commercial interests groups. It argues that the executive colluded with these interests during the Restoration period to use the state to increase the scale ofEngland's overseas trade. With the rising importance of parliament after 1689 regulatory initiative diffused to either local interests which focused on infrastructure projects or trading interests bent on defeating regulating statutes in ways that would lead to deregulation as other constitutional means of regulation (especially the privy council) retreated from view. The state continued to regulate to protect manufacturing (which also provided customs revenue) and to support the monopoly of theEastIndiaCompany (which provided money and materiel for the wars againstLouisXIV). As such the article offers a broader and more agile means to understand the economic connotations of constitutional change in this critical period.
Loop electrosurgical excision procedure and risk of vaginal infections during pregnancy: an observational study
Authors: Stout MJ , Frey HA , Tuuli MG , Cahill AG , Odibo AO , Roehl KA , Macones GA
Published: December 2014

Objective

To investigate the risk for preterm birth associated with vaginal infections in pregnancies after a loop electrosurgical excision procedure (LEEP), compared with women with no prior LEEP.

Design

Multicentre retrospective cohort study.

Setting

USA.

Population

Women with LEEP between 1996 and 2006 were compared with two unexposed groups who had cervical biopsy or Pap test, without any other cervical procedure, in the same calendar year.

Methods

The first pregnancy progressing beyond 20 weeks of gestation in women with prior LEEP was compared with pregnancy in women without LEEP. Stratified analysis according to the presence or the absence of vaginal infection during pregnancy was used to investigate whether the risk for preterm birth differed according to the presence or the absence of infection. The interaction between LEEP and vaginal infection was investigated using multivariable logistic regression with interaction terms, as well as the Mantel–Haenszel test for homogeneity.

Main outcome measures

Spontaneous preterm birth (<37 and <34 weeks of gestation).

Results

Of 1727 patients who met the inclusion criteria, 34.4% (n = 598) underwent LEEP prior to an index pregnancy. There was no increased risk for vaginal infections among women with LEEP compared with women without LEEP. Chlamydia infection and LEEP demonstrated significant interaction, suggesting that the presence of chlamydia infection in women with a history of LEEP augments the risk for preterm birth, compared with women with no history of LEEP.

Conclusions

Vaginal infections during pregnancy in women with a history of LEEP may be associated with an increased risk for preterm birth, compared with women with no history of LEEP.
The relationship between sleep quality and functional exercise capacity in COPD
Authors: Chen Rui , Tian Jing‐wei , Zhou Lu‐qian , Chen Xin , Yan Hai‐yan , Zeng Bin , Zhang Ming‐sheng
Published: December 2014

Background

Poor sleep is often associated with a series of health problems in patients with chronic obstructive pulmonary disease (COPD), but the relationship between sleep quality and functional exercise capacity has not been previously investigated.

Aims

To evaluate the relationship between quality of sleep and functional exercise capacity in clinically stable COPD.

Methods

One hundred three consecutive subjects with stable COPD were recruited. The subjects were assessed with the Pittsburgh Sleep Quality Index (PSQI) and divided into poor sleep group (PSQI >5) and good sleep group (PSQI ≤5). Subjects were also assessed with spirometry, 6‐min walk distance (6MWD), oxygen saturation (SPO2), the Epworth Sleepiness Scale, Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale, COPD Assessment Test (CAT), Modified Medical Research Council dyspnea scale and quadriceps muscle function.

Results

Poor sleep was present in 43.69% of the patients with COPD. Subjects with poor sleep had shorter 6MWD (t = −3.588, P < 0.001), greater age (t = 2.519, P = 0.013), worse quality of life (t = 5.487, P < 0.001) and more depression (t = 6.576, P < 0.001) or anxiety (t = 4.245, P < 0.001) symptoms. 6MWD showed significant negative correlations with the PSQI global score (r = −0.373, P < 0.001). Multiple stepwise regresion analysis showed that PSQI global score was an independent psychological predictor of 6MWD, and 6MWD was the only physical predictor of PSQI total score in patients with COPD.

Conclusion

There is a close relationship between sleep quality and functional exercise capacity in patients with COPD.
Hybrid Uptakes of Neoliberal Conservation in Namibian Tourism‐based Development
Authors: Silva Julie A. , Motzer Nicole
Published: December 2014

Neoliberal conservation schemes involving nature‐based tourism are implemented throughout the developing world to address rural poverty. Drawing on socio‐economic surveys and in‐depth interviews, this article uses the case of Uibasen Conservancy in Namibia to investigate social responses to neoliberal conservation. We find that people's aspirations for upward economic and social mobility lead them to participate in neoliberal conservation projects in an attempt to combine economic opportunities created by nature‐based tourism with traditional livelihood strategies. In this case, certain aspects of neoliberal conservation are perceived as a source of hope for non‐elites seeking to achieve economic self‐sufficiency and to ascend social hierarchies. We find that intra‐community power struggles dominate discourses of discontent and local‐level conflict which consequently masks the disruptive and anomic forces of the global tourism industry. We additionally provide insight into specific social contexts that may increase the allure of neoliberal conservation and explain why marginalized individuals may embrace some neoliberal logics despite — or, perhaps, because of — their disruptive tendencies.
Efficacy of metal and plastic stents for transmural drainage of pancreatic fluid collections: A systematic review
Authors: Bang Ji Young , Hawes Robert , Bartolucci Albert , Varadarajulu Shyam
Published: December 2014

Background and Aim

Metal stents are being used more frequently for transmural endoscopic drainage of pancreatic fluid collections (PFC) despite lack of data. The present systematic review was conducted to compare the rates of treatment success, adverse events and recurrence between patients undergoing metal versus plastic stent placement for endoscopic transmural drainage of PFC.

Methods

MEDLINE and EMBASE were searched to identify all published manuscripts that evaluated metal stents for endoscopic transmural drainage of PFC. All published studies from the same period involving plastic stent placement for PFC drainage that included >50 patients were also identified. Main outcome measures were to compare the rates of treatment success, adverse events and recurrence between the metal and plastic stent cohorts.

Results

Seventeen studies (881 patients) met inclusion criteria. There was no difference in overall treatment success between patients treated with plastic and metal stents (81% [95% CI, 77–84%] vs 82% [95% CI, 74–88%]) for both pseudocysts (85% [95% CI, 81–89%] vs 83% [95% CI, 74–89%]) and walled‐off necrosis (70% [95% CI, 62–76%] vs 78% [95% CI, 50–93%]). Also, there was no difference in the rates of adverse events (16% [95% CI, 14–39%] vs 23% [95% CI, 16–33%]) or recurrence (10% [95% CI, 8–13%] vs 9% [95% CI, 4–19%]) between plastic and metal stents.

Conclusions

Current evidence does not support routine placement of metal stents for transmural drainage of PFC. Randomized trials are needed to justify the use of metal stents for PFC drainage.
Tooth discolouration and internal bleaching after the use of triple antibiotic paste
Authors: Kirchhoff A. L. , Raldi D. P. , Salles A. C. , Cunha R. S. , Mello I.
Published: December 2014

Aim

To assess the discolouration of teeth with closed and open apices after placement of triple antibiotic paste (TAP, ciprofloxacin, metronidazole and minocycline) in the pulp chamber and whether discolouration could be reversed by internal bleaching procedures.

Methodology

Twenty extracted human mandibular premolars were divided into 2 groups (n = 10): teeth with closed apices (CA) and teeth with open apices (OA). After conventional access, the TAP was sealed in the pulp chamber for 3 weeks. The paste was removed by a rinse with sodium hypochlorite (NaOCl) and a mixture of sodium perborate and distilled water was sealed in the pulp chamber for 1, 2 and 3 weeks. The shade was measured by a spectrophotometer at six time periods: baseline (T0), after 3 weeks of placement of TAP (T1), after removal of TAP with a NaOCl rinse (T2) and after 1 (T3), 2 (T4) and 3 (T5) weeks of internal bleaching with sodium perborate paste. Data were collected based on the CIELAB‐CIE1976 (L*a*b*) system and analysed using t‐tests and anova.

Results

A significant decrease in the mean values of L* (lightness) was observed after treatment with TAP (T1, P < 0.05). Considerable increases in these values after bleaching with sodium perborate (T3 < T4 < T5) were found in both groups. The only significant difference in the intergroup analysis was between T1 and T2, in which ΔE values in the OA group were higher (P = 0.04).

Conclusions

TAP discoloured the tooth structure, but discolouration could be reversed with sodium perborate paste. In general, teeth with closed and open apices had the same rates of discolouration and bleaching.
Consumer attitudes towards and satisfaction with emergency contraception counselling: experience from clinic and retail pharmacy settings
Authors: Ragland Denise , Battle Marlene , Kueter Teddi J , Payakachat Nalin
Published: December 2014

Objective

To collectively assess consumer attitudes towards and satisfaction with emergency contraception (EC) counselling by student pharmacists in two different locations: an academic healthcare clinic and a retail pharmacy.

Methods

EC counselling was provided by trained student pharmacists utilizing a standardized education toolkit. Participants were asked to rate the counselling at the end of the knowledge survey. In addition to descriptive statistics, we compared the self-reported attitudes and satisfaction with the counselling between the two sites.

Key findings

The majority of participants from both settings rated ‘strongly agree’ on the attitude and satisfaction statements for the EC counselling. Participants from the clinic setting rated higher in two of the four statements than the participants from the retail setting.

Conclusions

Participants had positive attitudes towards and were highly satisfied with the EC counselling in both settings. EC counselling should be encouraged in practice settings.
The soil microbial community predicts the importance of plant traits in plant–soil feedback
Authors: Ke Po‐Ju , Miki Takeshi , Ding Tzung‐Su
Published: December 2014

Reciprocal interaction between plant and soil (plant–soil feedback, PSF) can determine plant community structure. Understanding which traits control interspecific variation of PSF strength is crucial for plant ecology. Studies have highlighted either plant‐mediated nutrient cycling (litter‐mediated PSF) or plant–microbe interaction (microbial‐mediated PSF) as important PSF mechanisms, each attributing PSF variation to different traits. However, this separation neglects the complex indirect interactions between the two mechanisms.

We developed a model coupling litter‐ and microbial‐mediated PSFs to identify the relative importance of traits in controlling PSF strength, and its dependency on the composition of root‐associated microbes (i.e. pathogens and/or mycorrhizal fungi).

Results showed that although plant carbon: nitrogen (C : N) ratio and microbial nutrient acquisition traits were consistently important, the importance of litter decomposability varied. Litter decomposability was not a major PSF determinant when pathogens are present. However, its importance increased with the relative abundance of mycorrhizal fungi as nutrient released from the mycorrhizal‐enhanced litter production to the nutrient‐depleted soils result in synergistic increase of soil nutrient and mycorrhizal abundance. Data compiled from empirical studies also supported our predictions.

We propose that the importance of litter decomposability depends on the composition of root‐associated microbes. Our results provide new perspectives in plant invasion and trait‐based ecology.
Flexibility Structure and Capacity Design with Human Resource Considerations
Authors: Akşin O. Zeynep , Çakan Nesrin , Karaesmen Fikri , Örmeci E. Lerzan
Published: December 2014

Most service systems consist of multidepartmental structures with multiskill agents that can deal with several types of service requests. The design of flexibility in terms of agents' skill sets and assignments of requests is a critical issue for such systems. The objective of this study was to identify preferred flexibility structures when demand is random and capacity is finite. We compare structures recommended by the flexibility literature to structures we observe in practice within call centers. To enable a comparison of flexibility structures under optimal capacity, the capacity optimization problem for this setting is formulated as a two‐stage stochastic optimization problem. A simulation‐based optimization procedure for this problem using sample‐path gradient estimation is proposed and tested, and used in the subsequent comparison of the flexibility structures being studied. The analysis illustrates under what conditions on demand, cost, and human resource considerations, the structures found in practice are preferred.
Use of aripiprazole for delirium in the elderly: a short review
Authors: Kirino Eiji
Published: December 2014

The effects and tolerability of antipsychotics in delirium treatment remain controversial. Compared to other antipsychotics, aripiprazole differs in pharmacological activity because it exerts its effect as a dopamine D2 partial agonist. The guidelines of the American Psychiatric Association rank aripiprazole highly among antipsychotics with regard to safety, and this drug is likely to be useful for delirium treatment. Here, we reviewed the efficacy and safety of aripiprazole for delirium. The results of our literature review on the efficacy and safety of delirium treatments suggest that aripiprazole is an effective treatment option for delirium in the elderly. Aripiprazole is as effective as other antipsychotics in improving delirium symptoms, and it is safer because it is less likely to cause extrapyramidal symptoms, excessive sedation, and weight gain. However, these findings are based on only a few clinical studies of elderly patients with delirium. Therefore, further investigations are necessary.
THE SYNERESIS OF BLOOD CLOTS
Authors: Pickering J. W. , Hewitt J. A.
Published: December 2014

(1) The syneresis of gels formed in wide‐mouthed vessels after the recalcification of oxalate and citrate plasmas is modified by (2) the speed of recalcification, (b) the temperature of the plasma (c) the amount of the surfaces exposed to forces of adhesion.

(2) The presence of fat globules and of “blood‐dust” in the before mentioned plasmas does not apparently affect the development of the contraction of clots.

(3) The effects of variations of the speed of recalcification and of variations of temperature may be wholly or partly masked when the recalcified gel is formed in small bore tubes.

(4) Release of the gel from adhesion to the vessel walls permits syneresis.

(5) The development of syneresis in recalcified oxalate and citrate plasmas in contact with flat glass plates is modified by variations in temperature and by other factors at present undetermined.

(6) When coagulation is delayed by the anticoagulants named, varying types of syneresis are found. Variations of temperature and the degree of exposure to the forces of adhesion modify the contraction of the clots formed.

(7) During the disappearance of platelets after the intravascular injection of “peptone” and of thymus nucleic acid the clots when formed exhibit typical syneresis.

(8) Blood platelets are apparently not the primary cause of syneresis.

(9) Adhesion plays an important part in the inhibition of syneresis.

(10) The absence of platelets may delay the contraction of clots by modifying the viscosity and adhesiveness of blood.

(11) The effect of contact on the coagulation of blood is continuous up to the formation of a contracted clot.

(12) Attention is drawn to the possible importance of changes of viscosity of the blood in haemorrhagic states.

(13) The anomalies apparent by a comparison of the records of various workers on the coagulation and syneresis of normal and of pathological bloods are commented on.

The authors are indebted to Dr P. A. Levene for a most generous supply of pure thymus and yeast nucleic acid.
THE MEASUREMENT OF THE DIAMETER OF ERYTHROCYTES. IV.—THE EFFECT OF ANTICOAGUI, ANTS AND OF VARIATIONS IN DRYING AND FIXING
Authors: Ponder Eric , Saslow George
Published: December 2014

1. It is shown that the mean diameter of cells in plasma is the same whether hirudin, heparin, or oxalate is used as an anticoagulant. The mean diameter in serum is the same as in plasma.

2. The statement of several observers that human red cells do not shrink on drying is shown to rest upon a technical error.

3. The mean diameter of dried cells is not altered by variations in the manner of drying, nor by the use of fixatives after drying is complete.
THE PERMANENT RESULTS OF DENERVATION OF A CUTANEOUS AREA
Authors: Sharpey-Schafer E.
Published: December 2014

In a cutaneous area which has been completely denervated by section of all the nerve fibres distributed to it, i.e. an area in which there is no overlapping or accessory supply of uncut nerve‐fibres and in which sufficient time has elapsed for regeneration of the cut nerves to take place, those fibres which subserve pain are permanently hypersensitive and confer a disagreeable character upon any sensation evoked by mechanical stimuli. The ordinary sensation of touch is not properly appreciated, being obscured by this hypersensitiveness to pain. A stimulation such as would produce a pleasant sensation of tickling on a normal cutaneous surface causes an unpleasant sensation of tingling over the denervated area. If the blunt point of a heated or cooled metal rod is allowed to come in contact with the area, the warm or cold feeling is complicated by the concomitant disagreeable sensation caused by contact of the rod with the skin. But if the rod is not allowed to touch the skin, the sensations of warmth or cold are felt without such concomitant disagreeable sensation.

Stated briefly, the following is the permanent condition of the original denervated area, as tested three years after section of the nerve supplying the area:—

The sensation of touch is abolished or is at any rate obscured by a concomitant sensation of pain.

Appreciation of warmth and cold has returned but in a somewhat diminished degree as compared with a normal area.

Sensation of pain is increased over the originally denervated area as compared with that felt over a normal area.

Trophic conditions are less favourable than in parts where the nerve‐supply has not been interfered with.
ON THE SPINAL PARASYMPATHETIC. PHYSIOLOGICAL SIGNIFICANCE OF THE SPINAL PARASYMPATHETIC SYSTEM IN RELATION TO THE DIGESTIVE TRACT
Authors: Kuré Ken , Ichiko Kin‐ichi , Ishikawa Kyusaburo
Published: December 2014

1. The vagus supply to the stomach includes, besides parasympathetic fibres, a great number of sympathetic fibres. Some of the sympathetic fibres exert an inhibitory influence upon its peristalsis. The parasympathetic fibres in the vagus are distributed all over the stomach, but they especially supply abundantly the cardia and fundus region.

2. The number of parasympathetic fibres which run to the intestine varies according to the individual animal; thus in one they amounted to 119, and in another there were only 13. It follows that the grade and region of innervation must show individual differences.

3. The greater splanchnic contains, besides the well‐known inhibitory fibres, many spinal parasympathetic excitatory fibres, coming from the dorsal roots of the thoracic segments. Their excitatory action is disclosed when the inhibitory fibres are interrupted by the application of nicotine to the cœliac ganglion. The spinal parasympathetic fibres supply not only the intestine but the stomach, especially its pyloric region. In the dog, the left splanchnic supplies more fibres to the stomach than the right, the right supplying only the pylorus. Both splanchnics have an excitatory action upon the intestine, after the sympathetic inhibitory fibres have been interrupted. The right splanchnic supplies especially the uppermost portion of the small intestine. In the cat, the greater splanchnic acts more effectively upon the stomach than in the dog.

4. The spinal parasympathetic fibres supply the intestine segmentally through the lumbar sympathetic trunk. Their excitatory action may be greater than the inhibitory action of the sympathetic fibres, so that stimulation of the lumbar sympathetic trunk without nicotine application is enough to provoke contraction and peristalsis of the corresponding region of the intestine. The lower part of the lumbar sympathetic trunk (4th and 5th ganglion) innervates the first portion of the large intestine. Stimulation of this part of the lumbar sympathetic causes contraction of the large intestine. Section of all rami communicates results in relaxation of the small intestine and of the upper part of the large intestine, but not of the uppermost part of the small intestine.

Nicotine application to the ganglia of the sympathetic trunk is followed by contraction and increased peristalsis of the small intestine (with the exception of its uppermost part); the upper part of the large intestine being also involved.
THE ACTION OF DRUGS ON THE PULMONARY CIRCULATION
Authors: Alcock P. , Berry J. L. , de Burgh Daly I.
Published: December 2014

In isolated lung preparations of the dog under negative pressure ventilation and perfused with defibrinated blood

1. Acetylcholine in the smallest effective doses causes a slight fall in pulmonary arterial pressure (or an increase in inflow), and in large doses a rise in pulmonary arterial pressure (or decrease in inflow). With small doses the venous outflow may show a slight decrease which is converted to an increase on raising the dose of acetylcholine.

2. The effects described above are in part, if not solely, independent of bronchomotor mechanisms.

3. The pulmonary arterial pressure rise or fall due to acetylcholine injections occur in nicotinised preparations, are enhanced by eserine and suppressed by atropine.

4. The apparent relationship between the type of vascular response to acetylcholine and the height of the perfusion pressure which is described, is determined by factors which are peculiar to the perfusion apparatus and which govern the concentration of the ester in the blood reaching the lungs. No evidence has been obtained that the degree of distension of the pulmonary blood‐vessels determines their response to acetylcholine.

5. Adrenaline in small doses may have no effect upon the pulmonary arterial pressure yet cause an increase in venous outflow.

6. A method is described for measuring the blood inflow and outflow from lungs under negative pressure ventilation.

The expenses of the research have been defrayed by a grant to one of us (I. de B. D.) from the Government Grant Committee of the Royal Society, to whom we express our thanks.
THE EFFECT OF INSULIN ADMINISTRATION ON THE RESPONSE OF THE PANCREAS TO PARASYMPATHETIC STIMULATION
Authors: Hebb Catherine O.
Published: December 2014

1. In the rabbit, the normal effect of electrical stimulation of the vagal nerves is to increase the flow of secretion from the pancreas and the concentration of enzymes in the juice.

2. Administration of insulin diminishes or reverses this effect, subsequent stimulation of the parasympathetic nerves producing either a smaller positive effect on the gland or a marked inhibition of the secretion.

3. This is not due to exhaustion of the acinous cells, since after insulin administration the injection of glucose or a large dose of pilocarpine or acetylcholine still produces an increased output of enzymes from the gland.

4. During insulin hypoglycæmia, if the vagi are intact, the output of lipase from the pancreas progressively diminishes, whereas when the vagi have been severed the output of lipase remains constant.

5. Some evidence was obtained that injection of glucose enhances the normal secretory effect of vagal stimulation on the pancreas.

The expenses of this investigation were defrayed by a grant given to the writer by the Banting Research Foundation of Toronto, whose help is hereby gratefully acknowledged.

I wish to express my appreciation of the helpful advice and criticism of Dr B. P. Babkin, under whose direction this work was carried out. I should like also to thank Dr D. L. Thomson for criticism of the manuscript of this paper. I am indebted to Miss J. F. Oswald for assistance in the preparation of the manuscript for press.
Sheep cardiac sarcoplasmic reticulum calcium‐release channels: modification of conductance and gating by temperature.
Authors: Sitsapesan R , Montgomery R A , MacLeod K T , Williams A J
Published: December 2014

1. The gating and conduction properties of single calcium‐release channels of sheep isolated cardiac junctional sarcoplasmic reticulum membranes incorporated into planar phospholipid bilayers were investigated under voltage clamp conditions at temperatures between 4 and 32 degrees C. 2. Single channel conductance was reduced linearly when temperature was decreased from 32 to 5 degrees C with a Q10 value of 1.5 between 10 and 20 degrees C. The apparent activation enthalpy for conductance between 32 and 5 degrees C was 6.16 +/‐ 1.2 kcal/mol. 3. Cooling the channel increased open probability (Po) when activating cytosolic calcium concentrations were varied within the range 0.1‐100 microM. At an activating free calcium concentration of 10 microM, channel Po increased from 0.13 +/‐ 0.05 at 23 degrees C to 0.69 +/‐ 0.07 at 5‐10 degrees C. 4. At sub‐activating calcium concentrations (100 pM) or high concentrations of calcium (greater than or equal to 1000 microM), the calcium‐release channel remained closed at 23 degrees C. Cooling the channel under these conditions did not increase Po. 5. Lifetime analysis indicates that with calcium as the sole activating ligand, the cooling‐induced increase in Po results from an increase in channel open lifetimes with no significant alteration in the frequency of channel opening. At 23 degrees C, the open and closed lifetime distributions of the calcium‐activated channel are best described by two and three exponentials respectively. At reduced temperatures (5‐10 degrees C), both open and closed lifetime distributions were best described by three exponentials. 6. At sub‐activating calcium concentrations, calcium‐independent channel openings could be induced by sulmazole (AR‐L 115 BS, 0.5‐10 mM). At 23 degrees C, with sulmazole as the sole activating ligand, the best fits to both open and closed lifetime distributions were obtained with three exponentials. At reduced temperatures (5‐10 degrees C), Po was increased. Gating was characterized by long open events, however the open and closed lifetime distributions were still best described by three exponentials. 7. The net effect of temperature reduction is an increase in calcium current through the channel. This finding is consistent with the suggestion that calcium release from the SR is a major factor in the initiation of rapid cooling contractures of mammalian cardiac muscle preparations.
Effect of Mg2+ on the control of Ca2+ release in skeletal muscle fibres of the toad.
Authors: Lamb G D , Stephenson D G
Published: December 2014

1. The effect of myoplasmic Mg2+ on Ca2+ release was examined in mechanically skinned skeletal muscle fibres, in which the normal voltage‐sensor control of Ca2+ release is preserved. The voltage sensors could be activated by depolarizing the transverse tubular (T‐) system by lowering the [K+] in the bathing solution. 2. Fibres spontaneously contracted when the free [Mg2+] was decreased from 1 to 0.05 mM, with no depolarization or change of total ATP, [Ca2+] or pH (pCa 6.7, 50 microM‐EGTA). After such a ‘low‐Mg2+ response’ the sarcoplasmic reticulum (SR) was depleted of Ca2+ and neither depolarization nor caffeine (2 mM) could induce a response, unless the [Mg2+] was raised and the SR reloaded with Ca2+. Exposure to 0.05 mM‐Mg2+ at low [Ca2+] (2 mM‐free EGTA, pCa greater than 8.7) also induced Ca2+ release and depleted the SR. 3. The response to low [Mg2+] was unaffected by inactivation of the voltage sensors, but was completely blocked by 2 microM‐Ruthenium Red indicating that it involved Ca2+ efflux through the normal Ca2+ release channels. 4. In the absence of ATP (and creatine phosphate), complete removal of Mg2+ (i.e. no added Mg2+ with 1 mM‐EDTA) did not induce Ca2+ release. Depolarization in the absence of Mg2+ and ATP also did not induce Ca2+ release. 5. Depolarization in 10 mM‐Mg2+ (pCa 6.7, 50 microM‐EGTA, 8 mM‐total ATP) did not produce any response. In the presence of 1 mM‐EGTA to chelate most of the released Ca2+, depolarizations in 10 mM‐Mg2+ did not noticeably deplete the SR of Ca2+, whereas a single depolarization in 1 mM‐Mg2+ (and 1 mM‐EGTA) resulted in marked depletion. Depolarization in the presence of D600 and 10 mM‐Mg2+ produced use‐dependent ‘paralysis’, indicating that depolarization in 10 mM‐Mg2+ did indeed activate the voltage sensors. 6. Depolarization in the presence of 10 mM‐Mg2+ and 25 microM‐ryanodine neither interfered with the normal voltage control of Ca2+ release nor caused depletion of the Ca2+ in the SR even after returning to 1 mM‐Mg2+ for 1 min, indicating that few if any of the release channels had been opened by the depolarization.(ABSTRACT TRUNCATED AT 400 WORDS)
Unresponsive afferent nerve fibres in the sural nerve of the rat.
Authors: Handwerker H O , Kilo S , Reeh P W
Published: December 2014

1. The proportion of primary afferent nerve fibres in a skin nerve of the rat that responded or failed to respond to mechanical or thermal stimulation of the skin in the noxious and non‐noxious range was analysed. 2. Activity of afferent nerve fibres was recorded from the dorsal roots. Units projecting into the sural nerve were selected using supramaximal electrical stimulation of the nerve stem. All other hindleg nerves were cut. 3. The receptive fields were searched by carefully examining the hindleg skin with noxious and innocuous mechanical, cooling and warming stimuli. Probing of the intrinsic foot muscles and manipulation of the ankle and toe joints was employed to recruit units projecting to deeper tissues. 4. In a first series of twenty‐two experiments, eighty‐nine rapidly conducting myelinated A beta units, thirty slowly conducting myelinated A delta units and 101 unmyelinated C units were investigated. Most units were identified as belonging to one of the established classes of cutaneous sensory units and this was also ascertained by a collision test. 5. Two A beta, eight A delta and forty‐six C fibres did not respond to any one of the stimuli. Electrical thresholds and conduction velocities of the unresponsive C fibres were not significantly different from those of the units responding to natural stimulation of their receptive fields. In the A delta group unresponsive and high threshold mechanoreceptive units were preferentially found among the units with the slowest conduction velocities. 6. In a second series of seven experiments, one single nerve filament containing responsive and unresponsive C fibres was tested repetitively at 30 min intervals. Twenty unresponsive units and seven units responding to noxious mechanical and/or heat stimuli were studied. Ten of the twenty initially unresponsive units became activated by mechanical and/or heat stimuli after observation times of 30‐150 min. Some of these units had mechanical thresholds as low as 64 mN (tested with calibrated von Frey hairs), or thermal thresholds down to 42 degrees C. 7. Two of the ten C units which became responsive in the course of an experiment later lost their responsiveness again. On the other hand, two of the C units which were initially responsive to noxious heat and/or noxious mechanical stimuli became completely unresponsive after repetitive stimulation, whereas one unit initially only responding to noxious heat became responsive to mechanical stimuli, suggesting that mechanical and heat responsiveness may be separately gained or lost by sensory C fibres.(ABSTRACT TRUNCATED AT 400 WORDS)
The medullary respiratory network in the rat.
Authors: Schwarzacher S W , Wilhelm Z , Anders K , Richter D W
Published: December 2014

1. In urethane or Nembutal anaesthetized and artificially ventilated Wistar rats, respiratory neurones of the ventrolateral medulla oblongata were analysed in extracellular (n = 74) and intracellular (n = 43) recordings. 2. Some respiratory neurones were identified as bulbospinal by their antidromic response to spinal cord stimulation at the C4 level. The neurones examined were not antidromically excited by vagal nerve stimulation. 3. Based on their discharge pattern in relation to efferent phrenic and vagal nerve activity, six types of respiratory neurones were classified: early‐inspiratory, throughout‐inspiratory, late‐inspiratory, post‐inspiratory, expiratory, and phase‐spanning expiratory‐inspiratory neurones. 4. Analysis of postsynaptic activities and IPSP reversal following chloride injection revealed post‐inspiratory and expiratory inhibition in inspiratory neurones a pronounced early‐inspiratory and a relatively weak expiratory inhibition in post‐inspiratory neurones, and an early‐inspiratory and post‐inspiratory inhibition in expiratory neurones. 5. In phase‐spanning expiratory‐inspiratory neurones the post‐inspiratory inhibition was strong and effectively blocked action potential discharge. Expiratory‐inspiratory neurones were quite similar to the group of inspiratory neurones, but seemed to receive tonic excitatory inputs not shunted by weak expiratory inhibition. This pre‐inspiratory discharge was readily blocked by weak negative DC injection. 6. Under conditions of experimental hypoxia, or long lasting lung inflation and non‐inflation, post‐inspiratory neurones displayed a second burst of discharge at the end of the expiratory phase in addition to their longer lasting post‐inspiratory discharge. 7. We conclude that in the rat the central respiratory rhythm is organized in three (inspiratory, post‐inspiratory, expiratory) phases, and that synaptic interaction within the medullary respiratory network of the rat occurs similarly to that described for the cat.
Mesencephalic stimulation elicits inhibition of phrenic nerve activity in cat.
Authors: Gallman E A , Lawing W L , Millhorn D E
Published: December 2014

1. Previous work from this laboratory has indicated that the mesencephalon is the anatomical substrate for a mechanism capable of inhibiting central respiratory drive in glomectomized cats for periods of up to 1 h or more following brief exposure to systemic hypoxia; phrenic nerve activity was used as an index of central respiratory drive. 2. The present study was undertaken to further localize the region responsible for the observed post‐hypoxic inhibition of respiratory drive. We studied the phrenic nerve response to stimulations of the mesencephalon in anaesthetized, paralysed peripherally chemo‐denervated cats with end‐expired PCO2 and body temperature servo‐controlled. 3. Stimulations of two types were employed. Electrical stimulation allowed rapid determination of sites from which phrenic inhibition could be elicited. Microinjections of excitatory amino acids were used subsequently in order to confine excitation to neuronal cell bodies and not axons of passage. 4. Stimulation of discrete regions of the ventromedial aspect of the mesencephalon in the vicinity of the red nucleus produced substantial inhibition of phrenic activity which lasted up to 45 min. Stimulation of other areas of the mesencephalon either produced no phrenic inhibition or resulted in a slight stimulation of phrenic activity. 5. The results are discussed in the context of the central respiratory response to hypoxia.
GABA‐mediated inhibition of medullary vasomotor neurones by area postrema stimulation in rats.
Authors: Sun M K , Spyer K M
Published: December 2014

1. The cardiovascular responses, together with the effects on medullary sympathoexcitatory (vasomotor) neurones of the rostral ventrolateral medulla, of area postrema stimulation have been studied in vivo. 2. Electrical (10 Hz) or chemical stimulation using microinjections of L‐glutamate of the area postrema produced a vasodepressor response and an inhibition of the medullary sympathoexcitatory neurones in the nucleus reticularis rostroventrolateralis (RVL), while similar stimulation in the adjacent nucleus tractus solitarii (NTS) caused increases in arterial pressure. 3. Single‐pulse stimulation of the area postrema revealed at least three influences on the activity of RVL vasomotor neurones, one being excitatory and two inhibitory. 4. The inhibitions evoked in the medullary vasomotor neurones on area postrema stimulation were blocked by ionophoretic application of bicuculline, a GABAA receptor antagonist, without altering the excitatory input to the same neurones. Bilateral microinjections of bicuculline into the RVL in regions where the vasomotor neurones had been identified totally eliminated the vasodepression due to area postrema stimulation. 5. These data support a role for the area postrema in cardiovascular control. It is concluded that the area postrema exerts its action on cardiovascular control in part via GABAergic inhibition of the ‘vasomotor’ neurones in the nucleus reticularis rostroventrolateralis.
Second messengers mediating activation of chloride current by intracellular GTP gamma S in bovine chromaffin cells.
Authors: Doroshenko P
Published: December 2014

1. Intracellular mechanisms and second messengers involved in chloride current activation by intracellular GTP gamma S (guanosine 5'‐O‐(3‐thiotriphosphate] in bovine chromaffin cells were studied using the whole‐cell patch‐clamp technique combined with measurements of intracellular calcium [Ca2+]i. 2. No correlation between the time of current activation and the appearance of [Ca2+]i transients was observed; intracellular introduction of sufficient EGTA (10 mM) to suppress the [Ca2+]i transients did not affect the current activation by GTP gamma S. 3. The cyclic nucleotides, cyclic AMP or cyclic GMP, did not activate the current when introduced intracellularly (50‐250 microM). The ability of GTP gamma S to activate the current decreased when cyclic GMP (250 microM), together with MgATP (2 mM), was added to the perfusate. 4. Neomycin (0.5‐1 mM), a presumed inhibitor of phospholipase C effectively prevented the current activation by GTP gamma S but it did not prevent [Ca2+]i transients. 5. Modulation of protein kinase C activity using specific inhibitors (H‐7, 300 microM; polymyxin B, 400 U/ml) or activators (phorbol ester PMA, 100 nM, 20‐90 min at 37 degrees C) did not affect the current activation by GTP gamma S nor did it cause current activation in the absence of GTP gamma S. 6. Activation of the current by GTP gamma S could be prevented by incubating the cells for 10‐15 min with 2.5 microM p‐bromophenacyl bromide (p‐BPB), an inhibitor of phospholipase A2 activity. Exogenous arachidonic acid (5‐10 microM), applied extracellularly or intracellularly, neither activated the current itself nor did it interfere with its activation by GTP gamma S. 7. Activation of the current by GTP gamma S could also be prevented by incubating the cells with 1 microM‐nordihydroguaiaretic acid (NDGA), an inhibitor of lipoxygenase, but not with indomethacin (2 microM), an inhibitor of cyclo‐oxygenase pathway of arachidonic acid metabolism. 8. It is suggested that chloride current activation by GTP gamma S in bovine chromaffin cells involves G protein‐mediated stimulation of phospholipase A2 activity and subsequent formation of lipoxygenase product(s) of arachidonic acid metabolism.