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PubMed1993

Costs and benefits of shell space construction.

"Shell space" is space constructed to meet future needs; it is space enclosed by an exterior building shell, but otherwise unfinished inside. The construction of shell space at the same time another facility is constructed, while adding to overall immediate construction costs, often can lower total expenditures over the long term. This article presents a model for evaluating the financial feasibility of constructing shell space during a capital construction project.

Cost-Benefit Analysis↗

PubMed1999

Antagonism of 5-hydroxytryptamine(4) receptors attenuates hyperactivity induced by cocaine: putative role for 5-hydroxytryptamine(4) receptors in the nucleus accumbens shell.

The localization of 5-hydroxytryptamine(4) (5-HT(4)) receptors suggests their role in the regulation of dopamine (DA) neurotransmission, a speculation that has been supported by neurochemical studies. Mesolimbic DA systems play a prominent role in mediating the behavioral effects of the abused psychostimulant cocaine, and the intent of the present study was to assess the role of 5-HT(4) receptors in the control of spontaneous and cocaine-induced activity. Systemic administration of the 5-HT(4) receptor partial agonist 1-(4-amino-5-chloro-2-methoxyphenyl)-3-[1-butyl-4-piperidinyl]1-propa none hydrochloride (RS 67333; 0.0001-1 mg/kg) or the 5-HT(4) receptor antagonist 4-amino-5-chloro-2-methoxy-benzoic acid-(diethylamino)ethyl ester hydrochloride (SDZ 205,557; 0.0001-1 mg/kg) did not significantly alter spontaneous activity, whereas SDZ 205,557 significantly attenuated cocaine-induced horizontal activity and rearing. To test the hypothesis that cocaine-elicited behaviors were modulated by 5-HT(4) receptors in the nucleus accumbens (NAc) shell, two separate groups of male rats were implanted with bilateral cannulas aimed at the NAc shell. Intra-NAc shell microinjections of either RS 67333 (1 or 3 microgram/0.2 microliter/side) or SDZ 205,557 (1-5 microgram/0.2 microliter/side) did not alter spontaneous activity observed after a systemic saline injection but did significantly attenuate the hyperactivity induced by systemic cocaine injection (10 mg/kg). These results support an involvement of 5-HT(4) receptors, particularly those in the NAc shell, in the locomotor stimulatory effects of cocaine. Furthermore, these data suggest that 5-HT(4) receptors may regulate behavioral processes dependent on mesolimbic DA pathways and may provide a novel target for the development of medications useful in the treatment of both drug dependence and psychiatric disorders.

4-Aminobenzoic Acid↗

PubMed1999

Motion at the modular acetabular shell and liner interface. A comparative study.

Excessive polyethylene debris generated from a total hip arthroplasty can lead to osteolysis and premature revision. Most of this polyethylene debris comes from the concave articulation. However, abrasive wear on the convex side of a modular polyethylene component also may play a role in this problem. Motion of a modular polyethylene liner with respect to its shell can lead to such abrasive wear. Six samples of modular acetabular components from eight manufacturers were tested for motion between the shell and the liner. Motion at the shell liner interface was detected by five fiberoptic sensors in the x, y, and z planes. Micromotion occurred at the shell liner interface in all designs tested. The magnitude of motion varied between manufacturers, ranging from 5 to 311 microns. Design features that limit motion may be advantageous in limiting the amount of polyethylene debris.

Acetabulum↗

PubMed2000

Failure of the locking mechanism between the acetabular metal shell and the polyethylene liner after primary total hip arthroplasty--a case report.

The short and intermediate-term clinical and radiographic results associated with Harris-Galante II porous-coated acetabular modular cup without cementing have been excellent in most patients. Nevertheless, its modular design introduced the potential for failure of the locking mechanism. There are four pairs of locking ties on the rim of metal shell to fix the polyethylene liner within it. Failure of any locking tine would result in less rigid fixation between the metal shell and the polyethylene liner and potentially produce instability or even disassembling of the liner. Only nine cases have been reported previously about the fractures of the locking tine, but it has never been reported in literature in Taiwan. We report a case with fracture of one tine following minor trauma at five years after primary total hip arthroplasty. During reoperation, scratching injury on the outer surface of the polyethylene liner in contact with the inferior tines of the metal shell was noted. Although no disassembling of the liner was noted, the remaining locking mechanism was found to be less rigid when the liner was taken out of the shell. The locking mechanism of HG II cup may be mechanically weak and may fail without major trauma; therefore, its design ought to be improved in an attempt to prevent postoperative dissociation of the polyethylene liner.

Acetabulum↗

PubMed2000

The wooden shell. The legend as representative of the early stage of development.

Legends serve as an important means of expressing fears, wishes, and fantasies. One of the best known and beloved legends worldwide is the nineteenth-century tale of Pinocchio, the wooden puppet who becomes a "real boy," or, as eventually becomes apparent, the boy enclosed in a wooden shell. This protective shell is an extremely interesting symbol and may be the reason the story holds a special place in the human experience. This paper discusses the significance of the wooden shell in the early protection of the developing psyche against invasive stimuli. In cases of normal development, this rigid enclosure is eventually discarded as the psyche matures. However, in pathological situations, it may remain a static, inhibitive shield. We describe the case of O., whose shell prevented his healthy interaction with the environment, and discuss how his problem was managed in the context of the legend. We also discuss related theories of the envelope of the ego.

Adult↗

PubMedDate not supplied

Serotonin1B receptor ligands in the nucleus accumbens shell do not affect the discriminative stimulus effects of amphetamine in rats.

Enhanced dopamine neurotransmission particularly, in the target area of the mesolimbic system, i.e. the nucleus accumbens (NAc), seems to be critical for the behavioral effects of amphetamine in rodents. Nonetheless, recent findings have also demonstrated a modulatory role of 5-hydroxytryptamine (5-HT; serotonin) in these effects. In the present study, we examined whether 5-HT1B receptors in the NAc shell are engaged in the discriminative stimulus of amphetamine. To this end male Wistar rats were trained to discriminate amphetamine (1 mg/kg, ip) from saline (ip) in a two-lever, water reinforced fixed ratio (FR) 20 task. After acquiring the amphetamine-saline discrimination, rats were stereotaxically implanted with bilateral cannulae aimed at the NAc shell and then infused with selective 5-HT1B receptor ligands. The ability of these drugs to substitute for or to alter (enhance or antagonize) the discriminative stimulus effects of amphetamine was examined. When given systemically, amphetamine (0.125-1 mg/kg) produced a dose-dependent increase in drug-lever responding. In substitution studies, microinjection of the 5-HT1B receptor agonist CP 93129 (1-10 microg/side) or the 5-HTIB receptor antagonist GR 55562 (1-10 microg/side) into the NAc shell did not evoke amphetamine-lever responding. Combination tests of 5-HT1B receptor ligands demonstrated that local injection with fixed doses of CP 93129 (1 or 10 microg/side) or GR 55562 (1 or 10 microg/side) with the submaximal doses of amphetamine (0.125-0.5 mg/kg) did not modify dose-response curves of the psychostimulant, nor did it affect its ED50 value. Our results seem to exclude a role for the NAc shell 5-HT1B receptors in the control of the discriminative stimulus effects of amphetamine. These findings also show that pharmacological stimulation of those receptors does not affect the amphetamine discrimination in rats.

Amphetamine↗

PubMedDate not supplied

Implication of the nucleus accumbens shell, but not core, in the acute and sensitizing effects of cocaine in rats.

Expression of cocaine-evoked motor behaviors appears to be dependent on dopamine neurotransmission particularly in the target area of the mesolimbic system, i.e. the nucleus accumbens (NAc). To test potential anatomical component of the locomotor effects of cocaine and expression of its behavioral sensitization, male Wistar rats were implanted with bilateral cannulae aimed at the two subregions of the NAc (the shell or the core) and then intracranially injected with cocaine (locomotor activity) or injected with cocaine given either systemically or intracranially following the repeated (5 days) systemic drug administration (sensitization). Sensitization was measured at early (5-day) and late (21-day) withdrawal periods. Acute administration of intra-NAc shell cocaine (6.73-50 microg/side) in a dose-dependent manner increased locomotor activity in rats; significant hyperactivation was observed after 25 and 50 microg/side of cocaine. Intra-NAc core injection of cocaine (12.5-50 microg/side) did not change rats' locomotor activity. After 5- or 21-day withdrawal, behavioral sensitization (ca. 2 times higher locomotor activity than that after acute drug administration) was observed when cocaine was injected either systemically (10 mg/kg) or intra-NAc shell (12.5-25 microg/side) in animals repeatedly treated with cocaine (10 mg/kg). No difference was observed in the response to the challenge with intra-NAc core cocaine (12.5-25 micorg/side) in rats treated repeatedly with cocaine at either withdrawal period. The above findings show the differential regulation of motor responses to cocaine within the subregions of the NAc. They also indicate a preferential effect for the NAc shell in expression of the acute and sensitizing effects of cocaine in rats.

Animals↗

PubMedDate not supplied

Active behavior and 1/f noise in shell-changing behavior of the hermit crabs.

Hermit crabs are known to carry a gastropod shell to prevent abdomen from injuring by predators and cannibalism. One can regard the shell as a boundary between inside and outside worlds for hermit crabs. We conducted an experiment in which hermit crabs without shells deal with artificial tubes. The situation without a shell requires a part of experimental setup to be regarded as inside by each hermit crab. We accept the distance of locomotion as the indication of the estimation process performed by an individual on parts of the experimental setup. As a result, behavioral hierarchy was found with respect to the way of constituting the boundary. At each level of hierarchy, active behavior produced 1/f noise in comparison with the passive one. It suggests that finding 1/f noise at each level of hierarchy may lead to a lower level of hierarchy in another situation.

Animals↗

PubMed2003

Time since discharge of shotgun shells.

A technique for the estimation of time since discharge of a given class of spent shotgun shells is presented. The technique involved the use of SPME (Solid Phase Microextraction) sampling from the atmosphere inside spent shotgun shells. Compounds absorbed on the SPME fiber were desorbed and analyzed with GC-MS. The decrease in concentration of the combustion product naphthalene was monitored in all shells over a two-month period. Three conditions were examined to prevent naphthalene from escaping prior to testing the shells. A glass vial was successfully incorporated to halt the dissipation of naphthalene. At room temperature the naphthalene peak can be measured for several months and the curve-fitting data can lead to an estimation of time since discharge.

Journal Article↗

PubMed2005

[Spectroscopic studies on different chemical composition between the shell and core of Radix Notoginseng].

Notoginseng (Sanqi) is one of the most important components of famous Chinese recipe (Yunan Baiyao) and possesses a wide variety of applications in clinical practice. It has been found that Sanqi of different size exhibits different curative effects. Such a phenomenon may be attributed to that the chemical constituent from shell region is different from that of core region. To prove the above-mentioned hypothesis, Ultraviolet-Visible (UV-Vis), FTIR, fluorescence spectroscopy, together with high performance liquid chromatography (HPLC) and electrospray ionization mass spectroscopy (ESI-MS) were utilized to study the variation of chemical compositions from shell and core regions of Sanqi. The results demonstrate that the chemical compositions of Sanqi from shell and core regions are different. In summary, differences in chemical composition between Sanqi shell and core were manifested from versatile aspects. Such differences shed a light on the different curative effects of Sanqi.

Chromatography, High Pressure Liquid↗

PubMed2005

[Study on weightlessness dynamics simulated by neutral buoyancy in air-driven shell].

OBJECTIVE: To provide theoretical support for weightlessness experiment simulated by neutral buoyancy. METHOD: An air-driven shell structure was simplified into a rigid body with constant mass and variable volume. Then, rigid body dynamic model and gasdynamic model of air-driven spherical shell were established. Finally, the kinematical laws and the residual pressure variety laws of air-driven spherical shell were obtained under constant mass-flux condition by computer simulation. RESULT: Under constant mass-flux condition, neutral buoyancy balance of air-driven spherical shell was unstable. CONCLUSION: The key to achieve stable neutral buoyancy balance is the design of the system controller.

Air Movements↗

PubMed1991

[Rapid diagnosis of infection by cytomegalovirus using early-antigen detection (shell vial)].

We performed an evaluation of early cytomegalovirus antigen detection (Shell-vial method) for rapid diagnosis of cytomegalovirus infection in patients at risk. A comparative, parallel, prospective study against conventional cell culture in 913 clinical specimens was carried out. Shell-vial technique detected an early cytomegalovirus antigen in culture using an indirect immunofluorescent method with monoclonal antibodies. Cytomegalovirus was detected in 210 specimens (23.0%). In 24 instances (11.4%), cytomegalovirus was only detected by culture, in contrast with 54 specimens (25.7%) that were only positive in Shell-vial (p less than 0.001; McNemar test). Mean detection time for cell culture was 9.2 days, and 16-24 h for the Shell-vial technique. This is a rapid, sensitive, specific and simple to perform method for diagnosis of cytomegalovirus infection. Nevertheless, the predictivity of cytomegalovirus disease was not improved by this technique.

Antibodies, Monoclonal↗

PubMedDate not supplied

[The shell of invertebrate and plant propagules: selective permeability and barriers].

In the experiments with seeds of Ericaceae, gemmuls of Spongia, statoblasts of Bryozoa, resting eggs and ephippia of Crustacea the hypothesis on selective permeability of propagule shells was tested. It was shown that the propagules are activated and develop until the moment of destruction of shell in the solutions of phenols, formaldehyde, CuSO4, K2Cr2O7, HgCl2, Ag2SO4, AgNO3, CoCl2 and NiSO4. It means that propagule shell is impermeable for these poisons but permeable for water and oxygen. The effectiveness of barrier can be various in different species but in some cases it is very high. The development of resistance to poisons of anthropogenic origin that were not familiar to organism earlier can be considered as an example of the rule (Rasnitzyn, 1971) according which relation between environmental variability and power of regulator is shifted to the priority of regulator. Selectively permeable shell for many organisms is a common adaptation that allows colonization of land and continental waters.

Adaptation, Physiological↗

PubMed1979

Shell tamponade in filtering surgery for glaucoma.

The glaucoma shell tamponade technique in filtering surgery for glaucoma is a technique for (1) decreasing the incidence of flat anterior chamber and choroidal separation postoperatively, (2) promoting the development of a low diffuse filtration area, and (3) increasing the possibility of achieving very low resulting postoperative pressure. The glaucoma shell technique is applicable to all types of filtration procedures, including conventional filtering procedures utilizing no scleral flap and those utilizing a scleral flap, such as trabeculectomy. It can be used at surgery or can be applied in the postoperative period to deal with flat or shallow anterior chambers immediately at the time of onset. The shell tamponade technique can be utilized to aid in the management of some cases of leaking bleb in the early postoperative period or in the late postoperative period. The technique for operative and postoperative use of the glaucoma shell tamponade technique and its closely related pressure dressing is a demanding and exacting art. Because the technique increases the possibility of very low resulting tensions, its use should be considered especially for cases in which very low pressures are desired, such as some cases of extremely advanced cupping and field loss and low-tension glaucoma.

Anterior Chamber↗

PubMed1983

[Effect of the harvest season on the composition of raw and fermented cotyledons of 2 varieties of cacao and shell fractions].

A study was carried out wherein during the period August 1979 to January 1980, samples of raw and fermented cacao were analyzed monthly. These included two varieties: Arriba, taken from a farm in "Quevedo", and the EET-19, grown in "Pichilingüe" by the Instituto Nacional de Investigaciones Agropecuarias (INIAP). Taking the ear of cacao as a basis, the weight of its main parts was determined. The proximal composition was established in the cotyledons, with significant statistical differences in regard to moisture, protein, and ether extract content according to the month of harvest. As to the fermentation process, differences in moisture, ether extract and ash content were detected; differences in the ether extract and ash content were found between the two varieties. The fat extracted from the cotyledons presented different iodine, saponification and acidity index values between the raw and fermented samples, but none were determined between the varieties; as far as the month of harvest is concerned, differences in the acidity index were observed. The percentage composition of the main fatty acids is reported (palmitic, stearic, oleic, and linoleic acids). In order to suggest possible industrial ways of utilizing the cacao shell by-product which is discarded by the shelling machine, the chemical characteristics of five fractions were determined based on the functioning of the shelling machine. The moisture, protein, ether extract, ash, crude fiber, theobromine, and caffeine contents varied among the fractions, and it was dependent on the broken "nibs" content. Differences in the protein, ether extract, and ash content, according to the months of production, were found. Obviously, the high fat content in fractions A (fine dust) and B (fine ground), which varied from 30 to 11 g/100 g, merits its extraction; the remainder meal has a valuable protein and alkaloid content. The chemical characteristics of the fat extracted from the shell of two fractions were similar to the fat extracted from the cotyledons.

Cacao↗

PubMed1980

Effect of stroke rate on velocity of a rowing shell.

In order to examine the effect of stroke rate changes on the velocity-time curve of a rowing shell, the 1976 U.S. Olymphic eight-oared crew was filmed rowing six trials each at stroke rates of 37, 39, and 41 strokes per min. Shell instantaneous velocity was calculated and plotted for positions throughout the stroke cycle and a cubic spline curve was fitted to these data points. Actual stroke rate, boat average velocity, and selected parameters of the velocity-time curves were calculated to examine the relationships between variables. In addition, times for phases of the stroke cycle were determined in order to analyze crew technique. Minimum shell velocity occurred approximately 27% into the leg drive phase and maximum velocity occurred during the middle of the seat movement phase. Average minimum shell velocity for all trials deviated -24.4% from the mean velocity while the average maximum velocity deviated +18.6%. A significant positive relationship (r = .66) was found between stroke rate and average velocity. In analyzing the phases of the stroke cycle, it was determined that increased boat velocity was accomplished by a greater application of force during the drive phase and, more importantly, the exertion of force over a greater percentage of the time for the stroke cycle.

Biomechanical Phenomena↗

PubMed1995

Glutamate receptors in the nucleus accumbens shell control feeding behavior via the lateral hypothalamus.

The nucleus accumbens in a brain region considered to be important in the regulation of appetitive behavior and reinforcement. The accumbens receives afferent input from corticolimbic and thalamic structures, which is primarily coded by excitatory amino acids (EAAs). The present studies investigated the role of EAA input to the nucleus accumbens in feeding behavior in rats, in two recently characterized subregions of the accumbens, the "core" and "shell". In the first series of experiments, it was shown that blockade of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) and kainate glutamate receptors in the medial part of the accumbens, corresponding to the medial shell subregion, resulted in a pronounced feeding response. Bilateral microinfusion of 6,7-dinitroquinoxaline-2,3-dione (DNQX, 0.25-0.75 micrograms/0.5 microliters), 6-cyano-7-nitroquinoxaline (CNQX, 0.75-1.5 micrograms), and 2,3-dihydroxy-6-nitro-7-sulfamoylbenzo-(F) quinoxaline (NBQX, 0.2-1.0 micrograms) markedly stimulated food intake immediately following infusion, in a dose-dependent manner. Infusion of DNQX into the central accumbens region, corresponding to the core, did not elicit feeding. Infusion of the NMDA antagonists 2-amino-5-phosphonopentanoic acid (AP-5) and MK-801 (dizocilpine maleate) did not elicit feeding in either region. The feeding response to DNQX was blocked by local coinfusion of AMPA. Systemic pretreatment with naltrexone (5 mg/kg) had no effect on the DNQX-feeding response; however, prior systemic administration of both D-1 and D-2 antagonists reduced the response by half, suggesting a modulatory role for dopamine in the response. Moreover, the feeding response was completely inhibited by concurrent infusion of the GABAA agonist muscimol (10, 25 ng) into the lateral hypothalamus, a major projection area of the accumbens shell. These findings demonstrate a selective role for non-NMDA receptors in the nucleus accumbens shell in ingestive behavior, and suggest an important functional link between two major brain regions involved in reward, the nucleus accumbens and lateral hypothalamus.

Animals↗

PubMed1994

[A comparative study on anti-ulcer action of unprepared and calcined oyster shell].

On experimental gastric ulcer models induced by 0.6mol/L HCl, ethyl alcohol or ligation of the pylorus, the preventive effects of unprepared oyster shell, calcined oyster shell 1(900 degrees C, 1h), calcined oyster shell 2(350 degrees C, 8h) were compared in Wistar rats. Results showed that antagonistic effects of calcined oyster shell 1 to the drug pathogenesis of peptic ulcer and the incidence of peptic ulcer after ligation of the pylorus were markedly greater.

Animals↗