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1.
Eur Phys J C Part Fields ; 84(1): 18, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38205101

RESUMO

High-precision searches for an electric dipole moment of the neutron (nEDM) require stable and uniform magnetic field environments. We present the recent achievements of degaussing and equilibrating the magnetically shielded room (MSR) for the n2EDM experiment at the Paul Scherrer Institute. We present the final degaussing configuration that will be used for n2EDM after numerous studies. The optimized procedure results in a residual magnetic field that has been reduced by a factor of two. The ultra-low field is achieved with the full magnetic-field-coil system, and a large vacuum vessel installed, both in the MSR. In the inner volume of ∼1.4m3, the field is now more uniform and below 300 pT. In addition, the procedure is faster and dissipates less heat into the magnetic environment, which in turn, reduces its thermal relaxation time from 12h down to 1.5h.

2.
Eur Phys J C Part Fields ; 83(11): 1061, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38021215

RESUMO

We present a novel Active Magnetic Shield (AMS), designed and implemented for the n2EDM experiment at the Paul Scherrer Institute. The experiment will perform a high-sensitivity search for the electric dipole moment of the neutron. Magnetic-field stability and control is of key importance for n2EDM. A large, cubic, 5 m side length, magnetically shielded room (MSR) provides a passive, quasi-static shielding-factor of about 105 for its inner sensitive volume. The AMS consists of a system of eight complex, feedback-controlled compensation coils constructed on an irregular grid spanned on a volume of less than 1000 m3 around the MSR. The AMS is designed to provide a stable and uniform magnetic-field environment around the MSR, while being reasonably compact. The system can compensate static and variable magnetic fields up to ±50µT (homogeneous components) and ±5µT/m (first-order gradients), suppressing them to a few µT in the sub-Hertz frequency range. The presented design concept and implementation of the AMS fulfills the requirements of the n2EDM experiment and can be useful for other applications, where magnetically silent environments are important and spatial constraints inhibit simpler geometrical solutions.

4.
Rev Sci Instrum ; 93(9): 095105, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36182526

RESUMO

We present the magnetically shielded room (MSR) for the n2EDM experiment at the Paul Scherrer Institute, which features an interior cubic volume with each side of length 2.92 m, thus providing an accessible space of 25 m3. The MSR has 87 openings of diameter up to 220 mm for operating the experimental apparatus inside and an intermediate space between the layers for housing sensitive signal processing electronics. The characterization measurements show a remanent magnetic field in the central 1 m3 below 100 pT and a field below 600 pT in the entire inner volume, up to 4 cm to the walls. The quasi-static shielding factor at 0.01 Hz measured with a sinusoidal 2 µT peak-to-peak signal is about 100 000 in all three spatial directions and increases rapidly with frequency to reach 108 above 1 Hz.

5.
Eur Phys J C Part Fields ; 81(6): 512, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34720721

RESUMO

We present the design of a next-generation experiment, n2EDM, currently under construction at the ultracold neutron source at the Paul Scherrer Institute (PSI) with the aim of carrying out a high-precision search for an electric dipole moment of the neutron. The project builds on experience gained with the previous apparatus operated at PSI until 2017, and is expected to deliver an order of magnitude better sensitivity with provision for further substantial improvements. An overview is of the experimental method and setup is given, the sensitivity requirements for the apparatus are derived, and its technical design is described.

6.
Eur Phys J A Hadron Nucl ; 57(4): 152, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34776778

RESUMO

Psychological bias towards, or away from, prior measurements or theory predictions is an intrinsic threat to any data analysis. While various methods can be used to try to avoid such a bias, e.g. actively avoiding looking at the result, only data blinding is a traceable and trustworthy method that can circumvent the bias and convince a public audience that there is not even an accidental psychological bias. Data blinding is nowadays a standard practice in particle physics, but it is particularly difficult for experiments searching for the neutron electric dipole moment (nEDM), as several cross measurements, in particular of the magnetic field, create a self-consistent network into which it is hard to inject a false signal. We present an algorithm that modifies the data without influencing the experiment. Results of an automated analysis of the data are used to change the recorded spin state of a few neutrons within each measurement cycle. The flexible algorithm may be applied twice (or more) to the data, thus providing the option of sequentially applying various blinding offsets for separate analysis steps with independent teams. The subtle manner in which the data are modified allows one subsequently to adjust the algorithm and to produce a re-blinded data set without revealing the initial blinding offset. The method was designed for the 2015/2016 measurement campaign of the nEDM experiment at the Paul Scherrer Institute. However, it can be re-used with minor modification for the follow-up experiment n2EDM, and may be suitable for comparable projects elsewhere.

7.
Tech Coloproctol ; 20(12): 859-864, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27844258

RESUMO

BACKGROUND: Sacral nerve stimulation is a common treatment for various pelvic floor disorders. It consists of the percutaneous introduction of electrodes through the posterior sacral foramina for therapeutic stimulation of the target sacral spinal nerve. The aim of our study was to determine the surface anatomical landmarks of the sacrum to facilitate identification of the posterior sacral foramina. METHODS: This study was conducted on 20 human cadavers. The cadavers were placed in a prone position, and all the soft tissues of the sacral region were removed to allow exposure of the osseous structures. Different measurements were taken in relation to the posterior sacral foramina, the posterior superior iliac spine (PSIS) and the median sacral crest (MSC). A median coefficient of variation (CV) was determined. RESULTS: The diameter of the second sacral foramen showed the greatest variability. The distances between each individual foramen and the MSC had an acceptable variability (CV < 20%). In contrast, the distance between foramina had a high variability. The distance between PSIS and the second posterior sacral foramen was also found to have an acceptable variability (CV < 20%). However, the angle formed by an horizontal line between PSIS and a line between PSIS and S2 foramina had high variability. CONCLUSIONS: We found that the distance between sacral foramina and MSC is relatively constant while the distance between foramina and the relations between foramina and PSIS is highly variable. Detailed knowledge of the anatomy may facilitate electrode placement and is complementary to the regular use of fluoroscopy.


Assuntos
Pontos de Referência Anatômicos , Terapia por Estimulação Elétrica/métodos , Ílio/anatomia & histologia , Região Sacrococcígea/anatomia & histologia , Cadáver , Feminino , Humanos , Ílio/inervação , Masculino , Decúbito Ventral , Região Sacrococcígea/inervação
8.
Eur. j. anat ; 12(1): 1-24, mayo 2008.
Artigo em Inglês | IBECS | ID: ibc-93395

RESUMO

Discussions at the inaugural meeting of aTrans-European Pedagogic Research Group forAnatomical Sciences highlighted the fact thatthere exist considerable variations in the legaland ethical frameworks throughout Europeconcerning body bequests for anatomicalexamination. Such differences appear to reflectcultural and religious variations as well as differentlegal and constitutional frameworks. Forexample, there are different views concerningthe “ownership” of cadavers and concerningthe need (perceived by different societies andnational politicians) for legislation specificallyrelated to anatomical dissection. Furthermore,there are different views concerning the acceptabilityof using unclaimed bodies that have notgiven informed consent. Given that in Europe (AU)


No disponible


Assuntos
Humanos , Obtenção de Tecidos e Órgãos/ética , Doadores de Tecidos/ética , Obtenção de Tecidos e Órgãos/legislação & jurisprudência , União Europeia , Legislação como Assunto
9.
Microsc Res Tech ; 69(4): 227-35, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16586484

RESUMO

Leishmaniosis is an anthropozoonosis caused by an intracellular protozoan parasite that causes a wide spectrum of diseases in humans and dogs worldwide. In the Mediterranean basin, Portugal, Central and South America, and in the Middle East, visceral leishmaniosis is caused by Leishmania infantum. In these areas, dogs are believed to be the natural reservoirs of this parasite. In the case of visceral leishmaniosis, the spleen is one of the several hematopoietic and immunocompetent organs involved. Since this viscera is a blood filter, the authors investigated the expression of the morphological and microvascular environment and modifications of the spleen cell population related to immunological responses to this parasitic condition. The tools used to perform this study were scanning electronic microscopy of intact tissue and corrosion casts, transmission electronic microscopy, histology and immunohistochemistry. The results reveal three important modifications concerning the spleen's microvascular architecture when compared with its normal pattern, independently of the serological titer obtained with indirect immunofluorescence. (1) A marked scarcity of the sinusoidal system sheet that surrounds the central artery/arteriole of the white pulp; (2) A huge development of pulp venules and veins; (3) The presence of a surprising development of reticular fibers. The authors postulate that independent of the virulence of the parasite involved and the type of immunity prevalent in a particular host, the spleen develops blood dynamic conditions that permit reduction in the speed of blood flow so that cells involved in immunological processes can proliferate and differentiate, and also contributes to trapping lymphocytes within the area through the differentiation of characteristics that resemble those of HEV endothelial cells.


Assuntos
Reservatórios de Doenças/veterinária , Leishmania infantum , Leishmaniose Visceral/veterinária , Baço/irrigação sanguínea , Baço/patologia , Animais , Cães , Fibrose , Imuno-Histoquímica , Leishmaniose Visceral/parasitologia , Microcirculação/ultraestrutura , Microscopia Eletrônica , Baço/parasitologia , Veias/ultraestrutura
10.
Surg Radiol Anat ; 26(5): 379-83, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15205918

RESUMO

Although the arterial supply of the human testis via the testicular artery is a well-studied subject, the pattern of approach that this vessel takes when reaching the gland is, on the other hand, not as well described. Based on the observation of angiological preparations of 196 adult human testes, the authors describe the presence of transmediastinal testicular vessels in one fourth of the cases. These were of two varieties, as regards the testicular mediastinum: centrifugal and centripetal. The centrifugal vessels were briefly mentioned in the nineteenth century scientific literature, undescribed in twentieth century anatomical studies and only recently referred to in color Doppler ultrasonographic studies; the centripetal vessels are previously undescribed. The authors propose the terms transmediastinal centrifugal and centripetal arteries to designate them.


Assuntos
Artérias/anatomia & histologia , Testículo/anatomia & histologia , Testículo/irrigação sanguínea , Adulto , Sulfato de Bário/administração & dosagem , Benzoatos/administração & dosagem , Meios de Contraste/administração & dosagem , Dessecação/métodos , Fixadores , Fluorescência , Formaldeído/administração & dosagem , Gelatina/administração & dosagem , Humanos , Peróxido de Hidrogênio/administração & dosagem , Masculino , Ilustração Médica , Oxidantes/administração & dosagem , Salicilatos/administração & dosagem
11.
Anat Histol Embryol ; 32(5): 263-70, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12969025

RESUMO

Numerous studies have been made regarding circulation via the red pulp of the spleen, and intense controversy surrounds the question as to whether or not endothelial continuity exists between arterial and venous vessels. Aware of this intense controversy, and in order to perform investigation over the spleen of dogs infected with a parasitic disease (future reports shall be done), the authors studied the vascularization of the normal dog spleen in order to define its normal pattern and evaluate the eventual changes of the circulation pattern under the parasitic condition. These studies led us to report, unequivocally, using complementary vascular replective techniques, that the normal dog's intermediary circulation is morphologically closed and of the open kind also. These findings are contrary to the thesis that defends the existence of a physiologically closed and morphologically open circulation in the dog spleen. Lymphatic vessels in the spleen of the dog are also demonstrated.


Assuntos
Cães/anatomia & histologia , Baço/irrigação sanguínea , Animais , Molde por Corrosão/veterinária , Cães/fisiologia , Feminino , Masculino , Microcirculação/ultraestrutura , Microscopia Eletrônica de Varredura/veterinária , Fluxo Sanguíneo Regional/fisiologia , Baço/ultraestrutura
12.
Eur. j. anat ; 7(1): 59-62, mayo 2003. graf, ilus
Artigo em Inglês | IBECS | ID: ibc-137854

RESUMO

The venous drainage of the human testis consists of two oppositely oriented currents towards and away from the mediastinum testis. These centrifugal and centripetal currents have been known and studied since the nineteenth century. Based on our own observations of 35 human testes prepared by the technique of serial cleared thick sections oriented in three axial body planes, we describe a submediastinal venous plexus, located on the deep surface of the mediastinum, receiving its tributaries from within the parenchyma and giving off collaterals to form the pampiniform plexus. We propose the name coronary submediastinal venous plexus owing to its most characteristic disposition (AU)


No disponible


Assuntos
Adulto , Humanos , Masculino , Testículo/anormalidades , Testículo/citologia , Doenças do Mediastino/induzido quimicamente , Doenças do Mediastino/metabolismo , Preparações Farmacêuticas/administração & dosagem , Preparações Farmacêuticas/provisão & distribuição , Testículo/patologia , Testículo/fisiologia , Doenças do Mediastino/diagnóstico , Doenças do Mediastino/patologia , Preparações Farmacêuticas , Preparações Farmacêuticas/metabolismo
13.
Ital J Anat Embryol ; 106(2 Suppl 2): 205-13, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11732578

RESUMO

The microvasculature of the corpus epididymis of adult domestic dogs (Canis familiaris) was studied using the technique of scanning electron microscopy of microvascular corrosion casts. The vascularization of the dog's corpus epididymis is accomplished by small arteries that course in the upper border of the organ. From these vessels arise first order arterioles (200-101 microm) which cross the surface of the epididymis and often show some coiling. The latter vessels supply second order arterioles (100-31 microm) which vascularize segments of the epididymal duct. The coiled and tight course of this duct is responsible for its peculiar microvascular arrangement. This is characterized by a 'bicycle-wheel' pattern and it is provided with precapillary or terminal arterioles (30-11 microm) nourishing a rich periductal network, mostly formed by anastomosing capillaries (10-3 microm). The periductal capillary network drains into postcapillary (11-30 microm), second order (31-100 microm) and first order (101-200 microm) venules, which empty into small calibre veins that course in the upper border of the epididymis. Anastomoses between vessels of the same type are often found. These are arteriovenous anastomoses mainly located at the periductal network. This study demonstrates that the epididymal microvasculature can be subdivided into a distribution microvascular network (DMN), formed by first and second order arterioles and venules, which presents a behaviour independent of the epididymal duct's sinuosities and a nutrition microvascular network (NMN), formed by precapillary arterioles, capillaries and post-capillary venules, characterised by the close relationship of the vessels with the loops of the epididymal duct.


Assuntos
Molde por Corrosão , Cães/anatomia & histologia , Epididimo/irrigação sanguínea , Microcirculação/ultraestrutura , Microscopia Eletrônica de Varredura , Animais , Arteríolas/ultraestrutura , Capilares/ultraestrutura , Masculino
14.
Acta Med Port ; 6(7): 327-30, 1993 Jul.
Artigo em Português | MEDLINE | ID: mdl-8379352

RESUMO

The authors describe a case of Cor Pulmonale due to Tumor Cell Embolization in a 42-year-old woman with no history of antecedent malignant disease. The primary tumor was a Choriocarcinoma which could not be found in postmortem examination. The pathophysiology, clinical manifestations and diagnostic evaluation of this entity are briefly discussed.


Assuntos
Coriocarcinoma/complicações , Células Neoplásicas Circulantes , Doença Cardiopulmonar/etiologia , Adulto , Feminino , Humanos
15.
Gastroenterol Clin Biol ; 10(1): 7-12, 1986 Jan.
Artigo em Francês | MEDLINE | ID: mdl-3956914

RESUMO

The characteristics and the prevalence of functional bowel disorders in the general French population are unknown. Based on an epidemiological inquiry in a random population of 1,200 persons who were not seeking care, residents in our country we established: the prevalence of symptoms suggestive of functional bowel disorders; the epidemiological differences between symptomatic subgroups which included abdominal pain with or without bowel dysfunction, diarrhea and constipation. The amount of cases and the prevalence in each subgroup were: abdominal pain, 165, 13.8 p. 100, painless constipation, 75, 6.3 p. 100, diarrhea, 10, 0.8 p. 100. As a whole, functional bowel disorders occurred in 20 p. 100 of our population. The "irritable bowel syndrome" group defined as abdominal pain and/or diarrhea differ from normal subjects by the following higher frequency of age under 50, subjects in active duty, antecedents of diverticulosis, influence of stress on symptoms, nausea, vomiting, migraines, pyrosis and number of visits to a doctor. However neither the sex-ratio nor professional occupation were relevant. The constipation group differed from normal because of the higher frequency of female sex, antecedents of hiatus hernia, use of laxatives but not because of age nor by the number of associated symptoms. In conclusion, functional bowel disorders occurred in 20 p. 100 of our population; two subgroups were clearly different from an epidemiological point of view, the irritable bowel syndrome (13 p. 100) and constipation (7 p. 100); therefore these two groups deserve a specific physiopathological, psychological and therapeutic approach.


Assuntos
Enteropatias/epidemiologia , Intestinos/fisiopatologia , Abdome , Adulto , Idoso , Constipação Intestinal/etiologia , Diarreia/etiologia , Feminino , França , Humanos , Enteropatias/diagnóstico , Enteropatias/fisiopatologia , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Fatores Socioeconômicos , Inquéritos e Questionários
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