Dipolar nuclear polarization via the spin diffusion of a dipole order.

We propose transfer of the paramagnetic impurity (PI) polarization to nuclei in bulk, outside the diffusion barrier, by using dipolar system of the nuclear spins. The transfer can overcome influence of the diffusion barrier and is proposed to be implemented in four stages. At the first stage, transition of the Zeeman PI order to the Zeeman order of nuclear spins inside the spin-diffusion barrier is occurred. During the second stage the Zeeman order of both the nuclear spins inside the barrier and the nuclear spins in bulk is transferred into the nuclear dipolar spin order. As a result, the nuclear dipolar spin reservoir inside the barrier acquires a lower spin temperature, and thus a gradient of the spin temperature of the nuclear dipolar spin system is created. Since the external magnetic field and the magnetic field created by PIs do not effect on the dipole-dipole interaction between the nuclear spins, the dipolar reservoir is common for all nuclear spins, both inside and outside the diffusion barrier. Restriction of the diffusion barrier is removed and the spin diffusion of the dipole energy and transfer of the spin dipolar order to bulk spins occurs without obstacles (the third stage). At the last stage, to register an NMR signal, the dipolar order of the bulk spins is transferred into the Zeeman order of these spins. Estimations show that enhancement of the polarization can reaches in the case of a 1H nuclear spin, ~220, for 13C ~850, and for 15N ~2130.

Location of paramagnetic defects in detonation nanodiamond from proton spin-lattice relaxation data.

We developed an approach for determining location of intrinsic paramagnetic defects in nanodiamonds from the data of proton spin-lattice relaxation of the surface hydrogen atoms. The approach was applied to the detonation nanodiamond (DND) of the diameter of 5 nm. We found that dangling bonds with unpaired electron spins are located within the near-surface belt at the distance of 0.3-0.9 nm from the DND surface. The NMR data are compared with the results of EPR measurements.

Effectiveness of rotavirus pentavalent vaccine under a universal immunization programme in Israel, 2011-2015: a case-control study.

OBJECTIVES: The use of rotavirus pentavalent vaccine (RotaTeq®) as a sole vaccine within rotavirus universal immunization programmes remains limited. We examined the effectiveness of RotaTeq in preventing rotavirus gastroenteritis (RVGE) hospitalization in Israel, after the introduction of universal immunization against the disease. METHODS: A test-negative case-control study included age-eligible children for universal RotaTeq immunization (aged 2-59 months, born in 2011-2015). Cases (n = 98) were patients who tested positive for rotavirus by immunochromatography; those who tested negative (n = 628) comprised the control group. Information on rotavirus immunization history was obtained through linkage with a national immunization registry. Vaccination status was compared between cases and controls, adjusted odds ratios (aORs) were obtained from logistic regression models, and vaccine effectiveness calculated as (1 - aOR)*100. RESULTS: Immunization with RotaTeq was less frequent in RVGE cases (73.5%) than in controls (90.1%), p < 0.001; this association persisted after controlling for potential confounders. Effectiveness of the complete vaccine series was estimated at 77% (95% confidence interval (CI): 49-90) in children aged 6-59 months, and 86% (95% CI: 65-94) in children aged 6-23 months; whereas for the incomplete series, the respective estimates were 72% (95% CI: 28-89) and 75% (95% CI: 30-91). Vaccine effectiveness was estimated at 79% (95% CI: 45-92) against G1P[8]-associated RVGE hospitalizations and 69% (95% CI: 11-89) against other genotype-RVGE hospitalizations. CONCLUSIONS: High effectiveness of RotaTeq as the sole rotavirus vaccine in a universal immunization programme was demonstrated in a high-income country. Although partial vaccination conferred protection, completing the vaccine series is warranted to maximize the benefit.

Size dependence of 13C nuclear spin-lattice relaxation in micro- and nanodiamonds.

Size dependence of physical properties of nanodiamond particles is of crucial importance for various applications in which defect density and location as well as relaxation processes play a significant role. In this work, the impact of defects induced by milling of micron-sized synthetic diamonds was studied by magnetic resonance techniques as a function of the particle size. EPR and (13)C NMR studies of highly purified commercial synthetic micro- and nanodiamonds were done for various fractions separated by sizes. Noticeable acceleration of (13)C nuclear spin-lattice relaxation with decreasing particle size was found. We showed that this effect is caused by the contribution to relaxation coming from the surface paramagnetic centers induced by sample milling. The developed theory of the spin-lattice relaxation for such a case shows good compliance with the experiment.

(13)C spin-lattice relaxation in nanodiamonds in static and magic angle spinning regimes.

We report on (13)C nuclear spin-lattice relaxation time (T1) dependence on the magic-angle-spinning (MAS) rate in powder nanodiamond samples. We confirm that the relaxation is caused by interaction of nuclear spins with fluctuating electron spins of localized paramagnetic defects. It was found that T1 is practically not affected by MAS for small particles, while for larger particles with lower defect density T1 is different in static and MAS regimes and reveals elongation with increasing MAS rate. This effect is attributed to suppression of nuclear spin diffusion by MAS. We propose an approach that describes T1 dependence on the MAS rate and allows quantitative analysis of this effect.

MQ NMR dynamics in dipolar ordered state at negative temperature.

We investigate theoretically the Multiple Quantum (MQ) NMR dynamics at negative absolute temperatures in systems of nuclear spins 1/2 coupled by the dipole-dipole interactions and with the initial conditions determined by the dipolar ordered state. Two different methods of MQ NMR are used. One of them is based on the measurement of the dipolar energy. The other method uses an additional resonance (π/4)y-pulse after the preparation period of the standard MQ NMR experiment. It is shown that at negative temperatures many-spin clusters and spin correlations are created faster, and the intensities of MQ coherences are higher than in the usual MQ NMR experiments. So, the eighth-order MQ coherence in 10-spin system of the cyclopentane molecule appears to be 1.5 times faster and its intensity is four orders higher than at positive temperatures. The proposed MQ NMR methods at negative absolute temperatures can be used for the investigation of many-spin dynamics of nuclear spins in solids.

Recent trends in the epidemiology of shigellosis in Israel.

We provide an update on the epidemiology of shigellosis in Israel using data generated by a sentinel laboratory-based surveillance network for the period 1998-2012. The average annual incidence of culture-proven shigellosis was 97/100 000. We estimated that each case of shigellosis accounted for 25 cases in the community indicating the high burden of disease. Orthodox Jewish communities, living in highly crowded conditions and with a high number of children aged <5 years were the epicentre of country-wide biennial propagated epidemics of S. sonnei shigellosis. S. flexneri was the leading Shigella serogroup in Israeli Arabs. S. flexneri 2a and S. flexneri 6 alternated as the most common serotypes. Both S. sonnei and S. flexneri isolates showed high rates of resistance to ampicillin and trimethoprim/sulfamethoxazole and very low rates of resistance to quinolones and third-generation cephalosporins. Shigellosis due to S. sonnei conferred 81% (95% confidence interval 69-89) protection against the homologous Shigella serotype when epidemic exposure re-occurred 2 years later. These data are of value in the process of Shigella vaccine development.

Antiferromagnetic Ordering of Magnetic Clusters Units in Nb(6)F(15).

We have studied the magnetic cluster compound Nb(6)F(15) which has an odd number of 15 valence electrons per (Nb(6)F(12))(3+) cluster core, as a function of temperature using nuclear magnetic resonance, magnetic susceptibility, electron magnetic resonance and neutron powder diffraction. Nuclear magnetic resonance of the (19)F nuclei shows two lines corresponding to the apical F(a-a) nucleus, and to the inner F(i) nuclei. The temperature dependence of the signal from the F(i) nuclei reveals an antiferromagnetic ordering at T < 5 K, with a hyperfine field of ~2 mT. Magnetic susceptibility exhibits a Curie-Weiss behavior with T(N) ~5 K, and µ(eff) ~1.57 µ(B) close to the expected theoretical value for one unpaired electron (1.73 µ(B)). Electron magnetic resonance linewidth shows a transition at 5 K. Upon cooling from 10 to 1.4 K, the neutron diffraction shows a decrease in the intensity of the low-angle diffuse scattering below Q ~0.27 Å(-1). This decrease is consistent with emergence of magnetic order of large magnetic objects (clusters). This study shows that Nb(6)F(15) is paramagnetic at RT and undergoes a transition to antiferromagnetic order at 5 K. This unique antiferromagnetic ordering results from the interaction between magnetic spins delocalized over each entire (Nb(6)F(12) (i))(3+) cluster core, rather than the common magnetic ordering.

Spin diffusion in multiple pulse spin-locking in solids containing paramagnetic impurities.

Spin diffusion and spin-lattice relaxation in solids containing paramagnetic impurities under influence of a multiple-pulse spin-locking radio-frequency sequence are studied theoretically and experimentally. The diffusion equation obtained provides a clue for determination of the time dependent magnetization. The spin-lattice relaxation time is calculated as a function of the correlation time and multiple-pulse field parameters. From the experimental data the spin diffusion coefficient, the radius of the spin diffusion barrier, and the correlation time for very slow molecular motion in polycrystalline (C(2)F)(n) system are estimated and found to be D∼7.1×10(-12)cm(2)/s, r(c)∼4.8×10(-10)m, and τ(c)∼10.2µs, respectively.

Transition of rheumatologic care, from teenager to adult: which health assessment questionnaire can be best used?

OBJECTIVES: Transition of care for adolescents includes a transfer from paediatric to adult health care. This requires a transfer of specific measurements, which evaluate disease profiles such as functional ability. One of the most common measurements is the Health Assessment Questionnaire (HAQ). METHODS: Results of the Childhood HAQ (CHAQ) and HAQ were compared among adolescents diagnosed with rheumatic diseases involving the musculoskeletal system. All adolescents had recently dealt with or would in the near future be dealing with transition. RESULTS: Overall results of both questionnaires were comparable; intra-class correlation for consistency (ICC) was 0.95 (95% confidence interval 0.93-0.97). For a smooth transfer from CHAQ to HAQ, both correlation and agreement are required. Agreement between both questionnaires was not found. Described by limits of agreement, results of HAQ can differ from CHAQ as much as 0.95. CONCLUSIONS: Despite strong correlations for consistency, lack of agreement was found in the results of CHAQ and HAQ. If correlation persists over time, this study suggests evaluating both the childhood and adult version of the HAQ during the transition period. When transfer into adulthood is completed, comparison to earlier tests at younger age is available and reliable.

[Oral cancer awareness of physicians and dentists in the Israeli army].

Oral cavity squamous cell carcinoma (OSCC) accounts for 2-3% of all body malignancies. The aim of this study was to asses the knowledge and awareness of general practitioners and the dental practitioners in the Israeli army to OSCC. Israeli's defense force's medical corps's dentists and physicians took part in this study. A questionnaire was constructed to obtain information about: Demographics, Knowledge concerning signs, symptoms and risk factors of oral cancer, Attitude on referral and knowledge transfer to patients, Satisfaction and need for farther guidance on the subject. The questionnaire was sent via E mail to all army physicians and dentists. 80% of the dentists and 35% of the physicians replayed. According to our study there is a knowledge gap between physicians and dentists in several areas: Physicians showed less awareness to the disease therefore, are less likely to do regular oral examinations. Physicians had less information about risk factors (especially alcohol) and are less likely to pass information about the risk factors to their patients. Suspicious lesions in the oral cavity were less recognized as such by physicians. This study shows the need to strengthen physicians' knowledge and awareness concerning oral cancer.

[Partial orthodontic treatment--a case report and its implications].

Several theories lie behind the development of lower incisors crowding. Nowadays, many adults are seeking for treatment to resolve this problem. The present case report describes development of mild lower incisor crowding during one year of partial orthodontic treatment in the maxillary arch of a young adult patient. In trying to explain what was behind the speedy process, which forced the orthodontist to add the lower arch to the treatment, we found that narrowing the upper arch in the canine's area was the best explanation to this pathological process. The effect of the upper arch width on the lower one is quoted in many publications but it is not related to the lower incisors crowding phenomenon.

[Prevalence of congenitally missing teeth in Israeli recruits].

AIM: To evaluate the prevalence of congenitally missing teeth in a population of 18-year old Israeli army recruits. PATIENTS AND METHODS: The study population consisted of 226 out of 280 random 18-year-old Israeli army male recruits. The panoramic radiographs of those who fitted the criteria were examined by two dentists. The absence of permanent teeth in those radiographs was recorded. RESULTS: The prevalence of tooth agenesis (including the third molars) was 43.8%. The prevalence of tooth agenesis excluding the third molars was 5.3%. There were 11 subjects (4.2%) with a missing lower 2nd pre-molar, 3 subjects (1.1%) presented congenitally missing maxillary lateral incisors. As for the third molars, 101 subjects (5.83%) presented hypodontia of at least one third molar. Hypodontia of lower third molar was more common than hypodontia of upper third (22.1% and 16.4% respectively). 20 subjects (7.6%) presented bilateral mandibular missing third molars, 13 (4.9%) presented bilateral maxillary missing third molars and nine (3.4%) presented combined bilateral maxillary and mandibular missing third molars. CONCLUSION: The prevalence of tooth agenesis in Israeli army recruits was found within the wide range of reported similar data in the literature with some unique characteristics to this population.

Dynamics of multiple quantum coherences in dipole-coupling spins in solid.

A perturbation method deals with dipolar coupling spins in solids is presented. As example of application the method, the multiple-quantum coherence dynamics in clusters of a linear chain of four nuclear spins and a ring of six spins coupled by dipole-dipole interaction are considered. The calculated 0Q and 2Q intensities in a linear chain of four nuclear spins and 6Q intensity in a ring of six spins vs. the duration of the preparation period agree well with the exact solutions (for linear chain of four nuclear spins) and simulation data (for linear chain of four nuclear spins and a ring of six spin).

The effects of sevoflurane and isoflurane on intracranial pressure and cerebral perfusion pressure after diffuse brain injury in rats.

Twenty-four adult male Wistar rats, weighing 220 to 290 g, were anesthetized with 30 mg/kg intraperitoneal sodium thiopental, then underwent a tracheostomy. After diffuse impact-acceleration brain injury (BI) was induced, each rat was paralyzed and mechanically ventilated with 30% O2 in nitrous oxide (N2O). The rats were assigned randomly to two groups, each of which received one of the two volatile anesthetic agents, sevoflurane or isoflurane. The anesthetics were administered at 0.5, 0.75, 1.0, and 1.25 minimal alveolar concentration (MAC) for 30 minutes each, respectively, and anesthesia was maintained at 0.75 MAC during the last hour of the study period. Intracranial pressure (ICP), mean arterial pressure (MAP), rectal and intrahemispheric temperatures, and end-tidal volatile anesthetic concentrations were monitored continuously throughout the 3 hours, with measurements recorded every 15 minutes. At baseline, there were no significant differences between the two groups regarding the monitored physiologic values. In the sevoflurane group, MAP fell significantly after 45 minutes, and a similar change was observed in the isoflurane group after 30 minutes (P < .05, P < .01, and P < .001, respectively). Intracranial pressure increased significantly at 45 minutes in the sevoflurane group (P < .01) and remained elevated from 60 minutes until the end of the study period (P < .01, P < .001). Although ICP increased in the isoflurane group, the change was not significant. Cerebral perfusion pressure (CPP) decreased in parallel with MAP, with the reduction in the sevoflurane group being more pronounced than that in the isoflurane group. The results demonstrated that, under the conditions of diffuse BI, animals that were anesthetized with sevoflurane had higher ICP and lower CPP levels than those anesthetized with isoflurane.

Healing the victim, the young offender, and the community via restorative justice: an international perspective.

The 1990s saw the enactment of much "get tough with young offenders" legislation in the United States. At the same, problems with our present punishment and treatment model, in which many youngsters cycle repeatedly through the justice and mental health systems, raised interest in restorative justice, a community-based alternative model emphasizing a balanced, negotiated approach to the needs of victims, offenders, and the community. After summarizing the philosophical bases underlying both models, this article describes the practice of restorative justice in New Zealand, where it was pioneered. Restorative justice has special relevance for Maori community in New Zealand and minority communities in the United States, where youth are consistently overrepresented in the courts, detention centers, and jails, and in which the juvenile justice system is seen as hostile and biased. Outcome data from New Zealand and early outcome research from the United States suggest that the restorative model, in which offenses are understood as a breakdown in social bonds, offers a hopeful alternative for offending youngsters, their families, and their communities.

Bedside percutaneous tracheostomy experience with 72 critically ill patients.

Tracheostomy is necessary in intensive care unit (ICU) patients requiring prolonged mechanical ventilation. As an alternative to the standard surgical method, percutaneous techniques are available. Seventy-two patients were electively selected for percutaneous tracheostomy (PCT) in a nine-bed combined medical-surgical intensive care unit. PCT was performed at bedside with the Portex Percutaneous Tracheostomy Kit that uses the Griggs technique. The procedure time and early complications were recorded. The procedure was successful in all patients. The average duration of placement was 7.4 min. There were no tracheostomy-related deaths. Major bleeding occurred in three patients and required surgical intervention. In one patient, minor bleeding occurred at the stoma site that resolved with applied pressure. Wound infections were treated with local antiseptics in two patients. These findings suggest that PCT is a simple, quick and safe procedure.

Spin diffusion of dipolar energy in NQR.

The theory of spin diffusion was extended to the case of nuclear dipolar order in solids containing paramagnetic impurities and nuclei with spin I > 1/2 having nuclear quadrupole moment. We show that spin diffusion process of dipolar order takes place in solids containing paramagnetic impurities. At the start of relaxation process, the direct relaxation regime is realized with non-exponential time dependence. Then the relaxation regime will be changed to diffusion-limited one. Using obtained expressions for the spin lattice relaxation times for these two relaxation regimes, the diffusion coefficient of the dipolar order in nuclear quadrupole resonance can be estimated from experimental data.

Spin diffusion and nuclear spin-lattice relaxation in irradiated solids: a multiple-pulse NQR study.

We present a detailed theoretical and experimental NQR multiple-pulse spin-locking study of spin-lattice relaxation and spin diffusion processes in the presence of paramagnetic impurities in solids. The relaxation function of the nuclear spin system at the beginning of the relaxation process is given by exp (-t/T1rho)alpha, where T1rho is spin-lattice relaxation time in rotating frame and alpha = d/6, d is the sample dimensionality. Then the relaxation proceeds asymptotically to an exponential function of time, which was attributed to the spin-diffusion regime. Using the experimental data obtained from the analysis of those two relaxation regimes in gamma-irradiated powdered NaClO3, spin diffusion coefficient has been determined and the radius of the diffusion barrier has been estimated.

Spin-locking in one pulse NMR experiment.

The response of a spin system to a long (in comparison to spin-spin relaxation time T2) radiofrequency pulse has been studied. We observed that the magnetization after the long pulse does not fall to zero at time t >> T2 for both on-resonance and off-resonance conditions. The dependencies of the magnetization on frequency offset, linewidth and radiofrequency power are investigated, both theoretically and experimentally. The question of the effective field direction is also discussed.