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1.
Eur Phys J C Part Fields ; 84(1): 18, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38205101

RESUMEN

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.
Artículo en Inglés | MEDLINE | ID: mdl-38021215

RESUMEN

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.

3.
Clin Immunol ; 251: 109344, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37098355

RESUMEN

Chronic nonbacterial osteomyelitis (CNO) is an autoinflammatory bone disease that primarily affects children and adolescents. CNO is associated with pain, bone swelling, deformity, and fractures. Its pathophysiology is characterized by increased inflammasome assembly and imbalanced expression of cytokines. Treatment is currently based on personal experience, case series and resulting expert recommendations. Randomized controlled trials (RCTs) have not been initiated because of the rarity of CNO, expired patent protection of some medications, and the absence of agreed outcome measures. An international group of fourteen CNO experts and two patient/parent representatives was assembled to generate consensus to inform and conduct future RCTs. The exercise delivered consensus inclusion and exclusion criteria, patent protected (excludes TNF inhibitors) treatments of immediate interest (biological DMARDs targeting IL-1 and IL-17), primary (improvement of pain; physician global assessment) and secondary endpoints (improved MRI; improved PedCNO score which includes physician and patient global scores) for future RCTs in CNO.


Asunto(s)
Antirreumáticos , Osteomielitis , Niño , Adolescente , Humanos , Consenso , Citocinas , Antirreumáticos/uso terapéutico , Osteomielitis/tratamiento farmacológico , Dolor/complicaciones , Dolor/tratamiento farmacológico , Enfermedad Crónica
4.
Arch Gynecol Obstet ; 308(4): 1151-1158, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-36087134

RESUMEN

OBJECTIVE: To determine whether the presence of anhydramnios significantly influences the sonographic estimated fetal weight (EFW) compared to a matched cohort with normal amniotic fluid volume. METHODS: The study sample of this retrospective case-control study consisted of 114 pregnant women who presented to a Tertiary Perinatal Clinic between 2015 and 2020. 57 of them presented with an anhydramnios and a matched cohort of 57 women with normal amniotic fluid volume. At time of admission, gestational age varied between 22 + 4 and 42 + 6 weeks of pregnancy. All women underwent detailed ultrasound assessment for EFW and amniotic fluid index. To determine EFW Hadlock's estimation formula I was used which is based on measurements of biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL). The EFW was compared with the weight at delivery. The maximum time interval between measurement and delivery was 5 days. RESULTS: There was neither a significant difference between the case and control group with regard to gestational age at ultrasound in days (median 249 days and 246 days, p = 0.97), nor to gestational age at birth (median 249 days and 247 days, p = 0.98). Concerning the newborns parameters, the body length at birth was not significantly different between the case and control group in centimeters (cm) (median 47 cm and 47 cm, p = 0.79). EFW in gram (g) was lower than birth weight in both groups and did not differ significantly between case and control group (estimated weight median 2247 g and 2421 g, p = 0.46; birth weight median 2440 g and 2475 g, p = 0.47). The difference between EFW and birth weight in percent (%) did not differ between the case and control group (median - 3.9% and - 5.6%, p = 0.70). The maternal parameters showed that the patients in the case group were younger (median 31 years and 38 years p = 0.20) and had a significantly higher body mass index (BMI) (median 27.3 kg/m2 vs 22.0 kg/m2, < 0.001) compared to the control group. CONCLUSION: Our study shows for the first time that EFW in women with anhydramnios can be determined sonographically just as accurately as in a matched cohort with normal amniotic fluid volume. A reliable estimation of fetal weight is crucial for optimal assessment of the newborns prognosis and counseling of the parents especially when advising women in the early weeks of pregnancy at the limit of viability.


Asunto(s)
Peso Fetal , Ultrasonografía Prenatal , Femenino , Embarazo , Recién Nacido , Humanos , Lactante , Peso al Nacer , Estudios Retrospectivos , Estudios de Casos y Controles , Edad Gestacional
6.
Rev Sci Instrum ; 93(9): 095105, 2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-36182526

RESUMEN

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.

7.
Clin Immunol ; 238: 109018, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35460903

RESUMEN

Chronic nonbacterial osteomyelitis (CNO) can cause significant morbidity, including bone pain and damage. In the absence of clinical trials, treatments include non-steroidal anti-inflammatory drugs, corticosteroids, TNF-inhibitors (TNFi) and/or bisphosphonates. In a retrospective chart review in the United Kingdom and Germany, we investigated response to TNFi and/or pamidronate. Ninety-one patients were included, receiving pamidronate (n = 47), TNFi (n = 22) or both sequentially (n = 22). Patients with fatigue [p = 0.003] and/or arthritis [p = 0.002] were more frequently treated with TNFi than pamidronate. Both therapies were associated with clinical remission at 6 months, and reduction of bone lesions on MRI at 12 months. While not reaching statistical significance, pamidronate resulted in faster resolution of MRI lesions. Fewer flares were observed with TNFi. Failure to respond to pamidronate was associated with female sex [p = 0.027], more lesions on MRI [p = 0.01] and higher CRP levels [p = 0.03]. Randomized clinical trials are needed to confirm observations and generate evidence.


Asunto(s)
Difosfonatos , Osteomielitis , Difosfonatos/uso terapéutico , Femenino , Humanos , Osteomielitis/tratamiento farmacológico , Osteomielitis/patología , Pamidronato/uso terapéutico , Estudios Retrospectivos , Resultado del Tratamiento , Inhibidores del Factor de Necrosis Tumoral
8.
Eur Phys J C Part Fields ; 81(6): 512, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34720721

RESUMEN

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.

9.
Eur Phys J A Hadron Nucl ; 57(4): 152, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34776778

RESUMEN

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.

10.
Phys Rev Lett ; 123(14): 143003, 2019 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-31702217

RESUMEN

We report results of a new technique to measure the electric dipole moment of ^{129}Xe with ^{3}He comagnetometry. Both species are polarized using spin-exchange optical pumping, transferred to a measurement cell, and transported into a magnetically shielded room, where SQUID magnetometers detect free precession in applied electric and magnetic fields. The result from a one week measurement campaign in 2017 and a 2.5 week campaign in 2018, combined with detailed study of systematic effects, is d_{A}(^{129}Xe)=(1.4±6.6_{stat}±2.0_{syst})×10^{-28} e cm. This corresponds to an upper limit of |d_{A}(^{129}Xe)|<1.4×10^{-27} e cm (95% C.L.), a factor of 5 more sensitive than the limit set in 2001.

11.
Opt Express ; 26(13): 17350-17359, 2018 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-30119547

RESUMEN

We report on an optically pumped magnetometer that uses multiple laser beams to pump and probe spin-polarized Cs atoms. The selected sensor geometry allows for operation in finite magnetic fields as well as close to zero field. In finite fields the magnetometer employs free spin precession signals to determine the field modulus and direction as described in a separate publication. This publication focuses on the magnetometer operation close to zero field, which is based on a ground state Hanle resonance. The four laser beams permit the simultaneous measurement of two orthogonal magnetic field components in a differential detection scheme that greatly suppresses technical laser power noise. Sensitivities better than 54 fT/Hz1/2 could be demonstrated simultaneously for both measurement channels in a well shielded environment. A minimum Allan deviation, limited by residual field fluctuations, of better than 40 fT was observed for integration times of 2s. The magnetometer achieves high sensitivity and stability in offset fields as well as close to zero field and is, thus, a universal tool for low frequency magnetic field measurements.

12.
Clin Immunol ; 196: 77-84, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-29723617

RESUMEN

The pathophysiology of chronic nonbacterial osteomyelitis (CNO) remains incompletely understood. Increased NLRP3 inflammasome activation and IL-1ß release in monocytes from CNO patients was suggested to contribute to bone inflammation. Here, we dissect immune cell infiltrates and demonstrate the involvement of monocytes across disease stages. Differences in cell density and immune cell composition may help to discriminate between BOM and CNO. However, differences are subtle and infiltrates vary in CNO. In contrast to other cells involved, monocytes are a stable element during all stages of CNO, which makes them a promising candidate in the search for "drivers" of inflammation. Furthermore, we link increased expression of inflammasome components NLRP3 and ASC in monocytes with site-specific DNA hypomethylation around the corresponding genes NLRP3 and PYCARD. Our observations deliver further evidence for the involvement of pro-inflammatory monocytes in the pathophysiology of CNO. Cellular and molecular alterations may serve as disease biomarkers and/or therapeutic targets.


Asunto(s)
Huesos/inmunología , Proteínas Adaptadoras de Señalización CARD/genética , Inflamasomas/genética , Interleucina-1beta/genética , Monocitos/inmunología , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Osteomielitis/inmunología , Infecciones Bacterianas/genética , Infecciones Bacterianas/inmunología , Infecciones Bacterianas/metabolismo , Infecciones Bacterianas/patología , Western Blotting , Huesos/metabolismo , Huesos/patología , Proteínas Adaptadoras de Señalización CARD/inmunología , Proteínas Adaptadoras de Señalización CARD/metabolismo , Estudios de Casos y Controles , Enfermedad Crónica , Metilación de ADN , Regulación de la Expresión Génica , Humanos , Inflamasomas/inmunología , Inflamasomas/metabolismo , Inflamación , Interleucina-1beta/inmunología , Interleucina-1beta/metabolismo , Receptores de Lipopolisacáridos/metabolismo , Monocitos/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/inmunología , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Osteomielitis/genética , Osteomielitis/metabolismo , Osteomielitis/patología , Reacción en Cadena en Tiempo Real de la Polimerasa
13.
Eur J Cancer Care (Engl) ; 27(2): e12606, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27859889

RESUMEN

We examined psychological parameters in family caregivers of palliative cancer patients before and after the death of the patients. Caregivers' data about depression and anxiety (Hospital Anxiety and Depression Scale), quality-of-life (Short Form-8 Health Survey), and social support (Oslo Social Support Scale) were collected at the beginning of home care (t1) and 2 months after the patient had died (t2). Regression models were employed to examine factors related to depression and anxiety in the bereaved caregivers. We interviewed 72 relatives, who were the primary caregiver of a patient. One-third (31.9%) of caregivers had high anxiety levels and 29.2% had high depression levels (t1, cut-off = 10). At t2, anxiety and depression had decreased significantly. There were no changes in quality-of-life over time. At both points of assessments, quality-of-life was lower than in the general population. Relevant factors for higher anxiety and depression in the bereaved caregivers were high levels of distress at t1, insufficient social support and low physical function. Bereaved caregivers were particularly depressed when they had been the spouse of the patient. Healthcare professionals should consider social isolation of caring relatives both during homecare and afterwards. Thus, it seems to be important to routinely offer support to spouses.


Asunto(s)
Ansiedad/etiología , Cuidadores/psicología , Trastorno Depresivo/etiología , Familia/psicología , Neoplasias/psicología , Cuidados Paliativos , Calidad de Vida , Adulto , Anciano , Anciano de 80 o más Años , Aflicción , Femenino , Servicios de Atención de Salud a Domicilio , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Apoyo Social
14.
Rheumatol Int ; 36(12): 1737-1745, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27730289

RESUMEN

Historically, osteomyelitis was considered an infectious disorder. More recently, inflammatory mechanisms were recognized causing a significant proportion of pediatric osteomyelitis. This study was to compare characteristics of children with chronic non-bacterial (CNO) and bacterial osteomyelitis (BOM). A chart review of osteomyelitis patients from the departments of pediatrics, pediatric surgery, orthopedic surgery, and oral and maxillofacial surgery was conducted in a tertiary referral center, covering the years 2004-2014. Institutional incidences of CNO (n = 49) and BOM (n = 56) were comparable. Differentiation between CNO and BOM based on clinical or laboratory findings was mostly impossible. However, children with BOM more frequently presented with local inflammatory signs (47 vs. 68 %, p = 0.040), fever (12 vs. 38 %, p = 0.003), and abscesses (0 vs. 39 %, p < 0.001). Peripheral arthritis (14 vs. 0 %, p < 0.001), inflammatory bowel disease (10 vs. 2 %, p = ns), and hyperostosis (29 vs. 4 %, p = 0.001) were more common in CNO. Whole-body MRI was performed in 76 % of CNO patients, unveiling multifocal lesions in 80 % (CRMO). Though considered a rare disorder, institutional incidences of CNO were comparable to BOM, and the discrimination between CNO and BOM solely based on clinical aspects was mostly impossible. This is of special interest, since a correct and timely diagnosis is of utmost importance for long-term outcomes in both disorders. Whole-body MRIs should be considered in chronic osteomyelitis to (1) detect clinically inapparent lesions in CNO and (2) indirectly exclude (usually unifocal) chronic bacterial infections. Prospective studies are warranted to establish evidence-based diagnostic and therapeutic approaches to CNO.


Asunto(s)
Infecciones Bacterianas/epidemiología , Osteomielitis/epidemiología , Adolescente , Infecciones Bacterianas/complicaciones , Infecciones Bacterianas/microbiología , Niño , Preescolar , Enfermedad Crónica , Femenino , Humanos , Incidencia , Lactante , Recién Nacido , Masculino , Osteomielitis/etiología , Osteomielitis/microbiología , Estudios Retrospectivos
15.
Br J Anaesth ; 116(6): 770-83, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27199310

RESUMEN

BACKGROUND: Improvement of postoperative pain and other perioperative outcomes remain a significant challenge and a matter of debate among perioperative clinicians. This systematic review aims to evaluate the effects of perioperative i.v. lidocaine infusion on postoperative pain and recovery in patients undergoing various surgical procedures. METHODS: CENTRAL, MEDLINE, EMBASE, and CINAHL databases and ClinicalTrials.gov, and congress proceedings were searched for randomized controlled trials until May 2014, that compared patients who did or did not receive continuous perioperative i.v. lidocaine infusion. RESULTS: Forty-five trials (2802 participants) were included. Meta-analysis suggested that lidocaine reduced postoperative pain (visual analogue scale, 0 to 10 cm) at 1-4 h (MD -0.84, 95% CI -1.10 to -0.59) and at 24 h (MD -0.34, 95% CI -0.57 to -0.11) after surgery, but not at 48 h (MD -0.22, 95% CI -0.47 to 0.03). Subgroup analysis and trial sequential analysis suggested pain reduction for patients undergoing laparoscopic abdominal surgery or open abdominal surgery, but not for patients undergoing other surgeries. There was limited evidence of positive effects of lidocaine on postoperative gastrointestinal recovery, opioid requirements, postoperative nausea and vomiting, and length of hospital stay. There were limited data available on the effect of systemic lidocaine on adverse effects or surgical complications. Quality of evidence was limited as a result of inconsistency (heterogeneity) and indirectness (small studies). CONCLUSIONS: There is limited evidence suggesting that i.v. lidocaine may be a useful adjuvant during general anaesthesia because of its beneficial impact on several outcomes after surgery.


Asunto(s)
Anestésicos Locales/efectos adversos , Anestésicos Locales/uso terapéutico , Lidocaína/efectos adversos , Lidocaína/uso terapéutico , Dolor Postoperatorio/tratamiento farmacológico , Periodo de Recuperación de la Anestesia , Humanos , Tiempo de Internación
16.
Rev Sci Instrum ; 86(5): 055109, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-26026560

RESUMEN

Several experiments in fundamental physics demand an environment of very low, homogeneous, and stable magnetic fields. For the magnetic characterization of such environments, we present a portable SQUID system that measures the absolute magnetic flux density vector and the gradient tensor. This vector-tensor system contains 13 integrated low-critical temperature (LTc) superconducting quantum interference devices (SQUIDs) inside a small cylindrical liquid helium Dewar with a height of 31 cm and 37 cm in diameter. The achievable resolution depends on the flux density of the field under investigation and its temporal drift. Inside a seven-layer mu-metal shield, an accuracy better than ±23 pT for the components of the static magnetic field vector and ±2 pT/cm for each of the nine components of the gradient tensor is reached by using the shifting method.


Asunto(s)
Ambiente Controlado , Campos Magnéticos , Diseño de Equipo , Helio , Impresión Tridimensional , Temperatura
17.
Anaesthesist ; 63(11): 825-31, 2014 Nov.
Artículo en Alemán | MEDLINE | ID: mdl-25227880

RESUMEN

BACKGROUND: Peripheral nerve catheters (PNC) play an important role in postoperative pain treatment following major extremity surgery. There are several trials reported in the literature which investigated the efficacy and safety of ultrasound (US) and nerve stimulator (NS) guided PNC placement; however, most of these trials were only small and focused mainly on anesthesiologist-related indicators of block success (e.g. block onset time and procedure time) but not primarily on patient-related outcome data including postoperative pain during movement. AIM: This retrospective analysis compared the analgesic efficacy and safety of US versus NS guided peripheral nerve catheters (PNC) for postoperative pain therapy in a large cohort of patients. MATERIAL AND METHODS: Data of patients (June 2006-December 2010) treated with US (nus = 368 June 2008-December 2010) and NS (nns = 574, June 2006-May 2008) guided PNC were systematically analyzed. Apart from demographic data, postoperative pain scores [numeric rating scale (NRS): 0-10] on each treatment day, the number of patients with need for additional opioids, cumulative local anesthetic consumption and catheter-related complications were compared. RESULTS: On the day of surgery patients treated with US-guided PNC reported lower NRS at rest (p = 0.034) and during movement (p < 0.001). Additionally, the number of patients requiring additional opioids on the day of surgery was lower in the US group (absolute difference 12.4 %, p = 0.001). Furthermore, the number of multiple puncture attempts (absolute difference 5.6 %, p < 0.001) and failed catheter placements (absolute difference 3.4 %, p = 0.06) were lower in the US group. There were no patients in both groups with long-lasting neurological impairment. CONCLUSION: This database analysis demonstrated that patients treated with US-guided PNC reported significantly lower postoperative pain scores and the number of patients requiring additional opioids was significantly lower on the day of surgery. The numbers of multiple punctures and failed catheter placements were reduced in the US group, which might be seen as an advantage of US-guided regional anaesthesia.


Asunto(s)
Analgesia , Anestesia de Conducción/métodos , Cateterismo Periférico/métodos , Estimulación Eléctrica/métodos , Bloqueo Nervioso/métodos , Nervios Periféricos/anatomía & histología , Nervios Periféricos/diagnóstico por imagen , Ultrasonografía Intervencional/métodos , Adulto , Anciano , Analgésicos Opioides/administración & dosificación , Analgésicos Opioides/uso terapéutico , Anestesia de Conducción/efectos adversos , Cateterismo Periférico/efectos adversos , Bases de Datos Factuales , Estimulación Eléctrica/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Bloqueo Nervioso/efectos adversos , Dimensión del Dolor , Dolor Postoperatorio/tratamiento farmacológico , Estudios Retrospectivos , Ultrasonografía Intervencional/efectos adversos
18.
Rev Sci Instrum ; 85(7): 075106, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25085172

RESUMEN

A versatile and portable magnetically shielded room with a field of (700 ± 200) pT within a central volume of 1 m × 1 m × 1 m and a field gradient less than 300 pT/m, achieved without any external field stabilization or compensation, is described. This performance represents more than a hundredfold improvement of the state of the art for a two-layer magnetic shield and provides an environment suitable for a next generation of precision experiments in fundamental physics at low energies; in particular, searches for electric dipole moments of fundamental systems and tests of Lorentz-invariance based on spin-precession experiments. Studies of the residual fields and their sources enable improved design of future ultra-low gradient environments and experimental apparatus. This has implications for developments of magnetometry beyond the femto-Tesla scale in, for example, biomagnetism, geosciences, and security applications and in general low-field nuclear magnetic resonance (NMR) measurements.

19.
Phys Rev Lett ; 112(11): 110801, 2014 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-24702343

RESUMEN

We report on the search for a CPT- and Lorentz-invariance-violating coupling of the He3 and Xe129 nuclear spins (each largely determined by a valence neutron) to posited background tensor fields that permeate the Universe. Our experimental approach is to measure the free precession of nuclear spin polarized He3 and Xe129 atoms in a homogeneous magnetic guiding field of about 400 nT using LTC SQUIDs as low-noise magnetic flux detectors. As the laboratory reference frame rotates with respect to distant stars, we look for a sidereal modulation of the Larmor frequencies of the colocated spin samples. As a result we obtain an upper limit on the equatorial component of the background field interacting with the spin of the bound neutron b(⊥)(n)<8.4 × 10(-34) GeV (68% C.L.). Our result improves our previous limit (data measured in 2009) by a factor of 30 and the world's best limit by a factor of 4.

20.
Br J Anaesth ; 111(4): 564-72, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23740042

RESUMEN

BACKGROUND: The aim of this meta-analysis was to compare the efficacy and safety of ultrasound (US) vs nerve stimulation (NS) guidance for peripheral nerve catheter placement. METHODS: This meta-analysis was performed according to the PRISMA statement and the recommendations of the Cochrane Collaboration. For dichotomous outcomes relative risks [RRs; 95% confidence intervals (CIs)] were calculated, while for continuous outcomes, mean differences (MDs; 95% CI) were calculated. All statistical analyses were performed using the Revman® statistical software (Version 5.1). RESULTS: Fifteen randomized controlled trials including 977 patients satisfied the inclusion criteria. Peripheral nerve catheters placed under US guidance showed a higher RR of 1.14 (95% CI: 1.02-1.27; P=0.02) for an overall successful block in comparison with NS. However, postoperative pain scales at movement (numeric rating scale: 0-10) were comparable between US- vs NS-guided peripheral nerve catheters 24 (MD: 0.08; 95% CI: -0.77 to 0.94; P=0.85) and 48 (MD: 1.0; 95% CI: -0.3 to 2.3; P=0.13) h after surgery. Patients receiving a US-guided peripheral nerve catheter had a lower RR of 0.13 (95% CI: 0.04-0.38; P=0.0002) for an accidental vascular puncture. CONCLUSIONS: There is evidence that US-guided peripheral nerve catheters show a higher success rate and a lower risk for an accidental vascular puncture compared with NS guidance. However, this difference resulted only in marginally lower postoperative pain scores at rest. Nevertheless, these results were influenced by heterogeneity and should be interpreted with caution.


Asunto(s)
Bloqueo Nervioso/métodos , Nervios Periféricos/diagnóstico por imagen , Ultrasonografía Intervencional/métodos , Cateterismo Periférico/efectos adversos , Cateterismo Periférico/métodos , Estimulación Eléctrica/métodos , Humanos , Bloqueo Nervioso/efectos adversos , Dolor Postoperatorio/prevención & control , Ensayos Clínicos Controlados Aleatorios como Asunto
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