An automated drift correction method for in situ NaI(Tl)-detectors used in extreme environments.

Gamma-ray detection systems are exposed to extreme environments during in situ measurements and the NaI(TI)-detectors in these systems are frequently subjected to significant temperature fluctuations. Several elements within these detectors are sensitive to temperature deviations, which ultimately causes a drift in gamma-ray spectra. This study aimed to determine the relationship between temperature deviation and spectrum drift and found a linear relationship over a wide range of energies. It was found that an increase in the detector temperature shifts the gamma-ray spectrum to lower channels, whereas a decrease in the detector temperature shifts the spectrum to higher channels. Using this information, a novel drift correction method based on the Gaussian distribution of the 1460 keV gamma-peak of 40K was developed. Dividing the peak into five regions of interest (ROI), a weighted gain correction factor is calculated based on the comparative skewness of the measured data and the sensitivity of the drift. The detector gain is then adjusted by the same factor to correct the drift in gamma-spectrum. This method was first tested in a simulated in situ environment, followed by in situ measurements along a beach. As expected, the gain adjustments followed the trend in detector temperature. The corrected counts in each of the five bins also presented good results and a close fit to the Gaussian distribution.

OVPSYCH2: A randomized controlled trial of psychological support versus standard of care following chemotherapy for ovarian cancer.

BACKGROUND: Fear of disease progression (FOP) is a rational concern for women with Ovarian Cancer (OC) and depression is also common. To date there have been no randomized trials assessing the impact of psychological intervention on depression and FOP in this patient group. PATIENTS AND METHODS: Patients with primary or recurrent OC who had recently completed chemotherapy were eligible if they scored between 5 and 19 on the PHQ-9 depression and were randomized 1:1 to Intervention (3 standardized CBT-based sessions in the 6-12 weeks post-chemotherapy) or Control (standard of care). PHQ-9, FOP-Q-SF, EORTC QLQ C30 and OV28 questionnaires were then completed every 3 months for up to 2 years. The primary endpoint was change in PHQ-9 at 3 months. Secondary endpoints were change in other scores at 3 months and all scores at later timepoints. RESULTS: 182 patients registered; 107 were randomized; 54 to Intervention and 53 to Control; mean age 59 years; 75 (70%) had completed chemotherapy for primary and 32 (30%) for relapsed OC and 67 patients completed both baseline and 3-month questionnaires. Improvement in PHQ-9 was observed for patients in both study arms at three months compared to baseline but there was no significant difference in change between Intervention and Control. A significant improvement on FOP-Q-SF scores was seen in the Intervention arm, whereas for those in the Control arm FOP-Q-SF scores deteriorated at 3 months (intervention effect = -4.4 (-7.57, -1.22), p-value = 0.008). CONCLUSIONS: CBT-based psychological support provided after chemotherapy did not significantly alter the spontaneously improving trajectory of depression scores at three months but caused a significant improvement in FOP. Our findings call for the routine implementation of FOP support for ovarian cancer patients.

Particle assemblies: toward new tools for regenerative medicine.

Regenerative medicine is a demanding field in terms of design and elaboration of materials able to meet the specifications that this application imposes. The regeneration of tissue is a multiscale issue, from the signaling molecule through cell expansion and finally tissue growth requiring a large variety of cues that should be delivered in place and time. Hence, the materials should be able to accommodate cells with respect to their phenotypes, to allow cell division to the right tissue, to maintain the integrity of the surrounding sane tissue, and eventually use their signaling machinery to serve the development of the appropriate neo-tissue. They should also present the ability to deliver growth factors and regulate tissue development, to be degraded into safe products, in order not to impede tissue development, and finally be easily implanted/injected into the patients. In this context, colloid-based materials represent a very promising family of products because one can take advantage of their high specific area, their capability to carry/deliver bio-active molecules, and their capacity of assembling (eventually in vivo) into materials featuring other mechanical, rheological, physicochemical properties. Other benefits of great interest would be their ease of production even via high through-put processes and their potential manufacturing from safe, biodegradable and biocompatible parent raw material. This review describes the state-of-the-art of processes leading to complex materials from the assembly of colloids meeting, at least partially, the above-described specifications for tissue engineering and regenerative medicine.

Improvement of chromatographic performances of in-situ synthesized hybrid C8 silica monoliths by reduction of structural radial heterogeneities.

Several modifications of a previously described protocol are proposed to improve the performances of in-situ synthesized C(8) hybrid silica monoliths. Our attention was focused on reducing the sources of radial heterogeneity that may be responsible for the poor efficiencies observed in the hydrodynamic elution mode. It was demonstrated that a decrease in the temperature of the capillary during the filling step equally to that of the polymerization mixture (0 degrees C), associated with a decrease of the gelation temperature to 20 degrees C along with a new pre-treatment of the capillary's internal walls [with a mixture of tetraethoxysilane (TEOS)/EtOH (1/3, v/v)] allows (i) increasing the radial homogeneity of the monolith, thus further enhancing the performances in the nano-liquid chromatography (nano-LC) mode, (ii) improving the capillary to capillary reproducibility in terms of permeability and efficiencies. In fact, the average minimum plate height H(min) was lowered from 24 to 14 microm and the capillary-to-capillary reproducibility of the synthesis was widely improved by factors two and three of reduction on the calculated standard deviation, respectively for both the efficiency in the nano-LC mode and the permeability. At last, the improved radial homogeneity and anchoring of the synthesized monoliths allowed increasing the inner diameter of the capillary (up to 150 microm) without any significant loss in efficiency. Finally, long term stability of the as-obtained monolithic stationary phases in terms of retention and efficiency was studied. In addition, the evaluation of their chromatographic behaviour was also achieved with the Tanaka test and the results were compared to those already published for commercial monoliths (Chromolith) as well as for particulate stationary phases.

Optimization of the single-step synthesis of hybrid C(8) silica monoliths dedicated to nano-liquid chromatography and capillary electrochromatography.

Hybrid silica monoliths functionalized with octyl groups and dedicated to chromatographic separations in the reversed-phase mode were directly synthesized within capillaries according to the protocol described by Yan et al. [L.J. Yan, Q.H. Zhang, Y.Q. Feng, W.B. Zhang, T. Li, L.H. Zhang, Y.K. Zhang, J. Chromatogr. A 1121 (2006) 92]. Although these monoliths allowed reaching high efficiencies in capillary electrochromatography (CEC), serious limitations prohibited their application in nano-liquid chromatography (nano-LC). Such limitations observed as poor performances in the nano-LC mode and the lack of reproducibility of the synthesis were related to the longitudinal morphological inhomogeneities of the hybrid material along the capillary. Thus, several modifications were conducted in the synthesis protocol in order to improve the resulting morphology of the monolith making it suitable for nano-LC separations. The influence of several critical parameters (such as the addition temperature of the basic catalyst and the hydrolysis duration) on the textural and chromatographic properties had been extensively studied. It was found that a decrease (i.e. 0 degrees C) of the temperature addition of the basic catalyst associated with a shorter hydrolysis duration (1h instead of 6h) allowed (i) delaying the gelation time and consequently facilitating the capillary filling step, (ii) increasing the structural homogeneity of the hybrid monoliths, i.e. their chromatographic performances in nano-liquid chromatography also (iii) greatly improving the reproducibility of the synthesis within the capillary without impairing the material's carbon load, i.e. the incorporation of the less hydrolysable C(8) precursor. The resulting hybrid monoliths afforded retention factors comparable to that previously obtained for C(18) grafted silica monoliths and efficiencies that are the best ever recorded in nano-LC with hybrid monoliths and that are close to the ones achieved with grafted silica monoliths. In fact, this modified protocol allowed a significant improvement of the performances in nano-LC which could be observed by the decrease of the mean value of H(min) going from 123 microm (Yan's protocol) to 24 microm (modified protocol) for a same length of capillary (l = 8.5 cm). In addition, the reproducibility of the synthesis was greatly improved through a factor six of reduction on the calculated standard deviation of these efficiencies. The high permeability and longitudinal homogeneity of the synthesized monolith allowed increasing the capillary length (for example, a 75-cm capillary was conveniently filled with hybrid silica monolith) and the column could be eluted at a very low backpressure leading to chromatographic performances up to 40,000 plates. Finally, the good efficiencies in the nano-LC mode combined with the excellent performances already present in the CEC mode led to fast (less than 1 min) and high efficient separations in the pressurized capillary electrochromatography (p-CEC) mode.

Influence of the hydrothermal treatment on the chromatographic properties of monolithic silica capillaries for nano-liquid chromatography or capillary electrochromatography.

In the last decade, silica monolithic capillaries have focused more and more attention on miniaturized separation techniques like capillary electrochromatography (CEC), nano-liquid chromatography (nano-LC) and chip electrochromatography owing to their unique chromatographic properties and their simplified preparation compared with packed columns. They are synthesized according to a sol-gel multi-step process that includes, after a gelation step at 40 degrees C leading to the formation of the macropores network and the silica skeleton, a post-gelation step (hydrothermal treatment at 120 degrees C in basic medium) that allows to tailor the mesopores and finally a calcination or a washing step to remove remaining polymers. In order to reduce the synthesis time, the number of synthesis steps and above all the temperature synthesis, to adapt the synthesis of such silica monoliths in polymeric microsystem devices, we extensively studied the influence of the hydrothermal treatment and its duration on textural (pore size distribution) and chromatographic properties (retention, efficiency) of in situ-synthesized capillary monoliths in nano-LC and CEC. This study was performed on pure silica and octyl chains grafted silica monoliths. Untreated monoliths show small pores (<6 nm), whereas hydrothermally treated monoliths exhibit medium and large mesopores (8-17 nm). It was demonstrated that the hydrothermal treatment at 120 degrees C was not necessary for pure silica monolithic capillaries dedicated to normal phase liquid chromatography or hydrophilic interaction liquid chromatography (HILIC) and electrochromatography: the suppression of the hydrothermal treatment did not impair efficiencies in CEC and in nano-LC but contributed to increase in retention factors. Minimal plate heights of ca. 5 microm in CEC and 6 microm in nano-LC were obtained with or without hydrothermal treatment with bare silica. In the same way, the hydrothermal treatment was not necessary for grafted silica monoliths only dedicated to CEC. However, the results clearly indicate that the hydrothermal treatment becomes essential before grafting in order to preserve the efficiency of the monolithic silica capillaries dedicated to nano-LC: in this particular case, the suppression of the hydrothermal treatment leads approximately to a loss of a factor two in efficiency.

Factors affecting food choice in relation to venison: A South African example.

Meat is a universally valued and sought-after source of human nutrition. However, concerns are raised about the health implications of eating too much saturated animal fat. This also applies to South Africa where the high incidence of heart disease and cancer is often linked to consumption of red meat. Despite venison offering a healthy alternative to beef and lamb, its consumption is low. A review of appropriate literature and the perceptions, opinions and preferences of 300 South African consumers resulted in a simplified framework of consumer and market related issues that could influence consumers' preference for wild venison. Consumer-related factors include health considerations, sensory variables, social interactions, familiarity and habit, psychographics and demographics, while the most important market-related issues comprise price, distribution and promotion. An understanding of all these factors is required to better target the promotion of venison as a healthy food choice.

Performance of parotidectomy in nonspecialist centers.

OBJECTIVE: To ascertain whether parotidectomy could be safely performed in smaller centers. The results of parotid surgery in a smaller center were reviewed and the major outcome measures compared with the results in the English literature from the best-known centers. DESIGN: Retrospective analysis of case series comprising 168 consecutive parotid surgical procedures in a district general hospital for a 15-year period (1985-1999). The follow-up ranged from 1 to 15 years with a mean of 8 years. Sixty-three patients had a follow-up of over 10 years. Revision procedures and surgery for malignant tumors were excluded from the study. SETTING: Warwick Hospital, a district general hospital in the United Kingdom, catering to a population of 300,000, with a case mix that is typical for a primary care hospital. MAIN OUTCOME MEASURES: Permanent facial palsy, temporary facial palsy, and recurrence rate. Other variables included age, sex, name of the surgeon, histopathologic features of the specimen, duration of follow-up, and other complications. RESULTS: There were 154 consecutive operations within the study period, performed by 2 ear, nose, and throat surgeons and 1 general surgeon. Eight cases were excluded because of cancer or revision, yielding a final figure of 146 for analysis. There were 25 cases of temporary facial palsy and no incidence of permanent facial palsy during the study period. However, recurrence of the tumor was noted in 4 patients, all of whom opted for revision surgery with successful outcomes. CONCLUSIONS: Parotid surgery for benign disease can be as safely performed in smaller centers as in larger centers. However, our study did not support the view that only a specified single surgeon should do parotid surgery, since there is no significant difference in the major outcome measures between different surgeons.

Suppression of the sawtooth instability in a storage ring by free-electron laser: an example of nonlinear stabilization by noise.

The stabilization of nonlinear excitations by noise is a topic of fundamental importance in many physical problems. We discuss a genuine example within the context of storage ring-free electron laser physics, by presenting a model which allows the characterization of the system evolution and the determination of the conditions leading to the suppression of instabilities of sawtooth type. The conclusions of the model are confirmed by a comparison with experimental results on the Super Aco Storage Ring-Free Electron Laser.

Miniature all-fiber devices based on CO(2) laser microstructuring of tapered fibers.

A focused carbon dioxide laser beam is used to microstructure fibers that have already been narrowed by conventional fiber tapering. We describe three new miniature devices made with this technique: a fused fiber microcoupler with an interaction length of 200 mum, a long-period grating made from a periodic chain of microtapers, and a new type of prolate whispering-gallery mode microcavity.

Lack of correlation between DNA ploidy, Langerhans cell population and grading in oral squamous cell carcinoma.

This study was undertaken to determine the inter-observer reproducibility of the invasive cell grading method on oral squamous cell carcinomas and to correlate this with the DNA ploidy status and Langerhans cell (LC) population. Fifty formalin-fixed paraffin-embedded blocks that contained both tumor and adjacent normal epithelium were randomly selected. DNA ploidy analysis was performed on a flow cytometer and the LC population was determined using an immunohistochemical technique with anti-S100 and anti-HLADR primary antibodies. The inter-observer correlation of the total malignancy score and individual morphologic features was highly significant. Thirty-two of the 50 tumors were graded as poorly differentiated and 18/50 as moderately differentiated. Thirteen of 25 poorly differentiated tumors had an aneuploid DNA content compared with 9/18 of the moderately differentiated group. No statistical differences in the LC counts between the poorly and moderately differentiated and aneuploid and diploid carcinomas were found. This study showed that the invasive cell grading method is reproducible but no correlation was found between the grading results and the ploidy status or LC count.

Antibiotic-loaded biodegradable bone cement for prophylaxis and treatment of experimental osteomyelitis in rats.

A biodegradable, particulate composite bone cement containing gentamicin and vancomycin was used for both treatment and prophylaxis of Staphylococcus aureus osteomyelitis in rats. Osteomyelitis was established by inoculating S. aureus into holes that were drilled in the proximal tibiae and were filled with polymethylmethacrylate (PMMA) cylinders. The cylinders were left in place for 3 weeks. The infections were serially evaluated by clinical and radiographic examination and by quantitative culture for colony forming units (CFUs) at the time the rats were killed. For treatment, cements containing antibiotic were implanted in animals that had established osteomyelitis and were left in place for an additional 3 weeks. Sites treated with biodegradable cement containing antibiotics exhibited significantly fewer CFUs in comparison with controls (p < 0.01). Sites treated prophylactically with the biodegradable cement developed no infections as evaluated by clinical or radiographic criteria or by quantitative culture. At this relatively early time, no significant difference in therapeutic effectiveness was found when either the biodegradable cement or PMMA was used as a carrier for antibiotics.

HIV-1 and HIV-2 infections in men attending sexually transmitted disease clinics in Abidjan, Côte d'Ivoire.

OBJECTIVE: (1) To determine the prevalence of HIV-1 and HIV-2 infections and associated risk factors in men attending Abidjan's three sexually transmitted disease (STD) clinics; (2) to examine the use of such sites for epidemiological surveillance. DESIGN: Cross-sectional study. SETTING: Abidjan's two main STD clinics (Clinics A and T), and the University Hospital Dermatology outpatients clinic. PATIENTS: Consecutive patients with genitourinary symptoms. MAIN OUTCOME MEASURES: Prevalence of reactivity to HIV-1, HIV-2, and both viruses; descriptive characteristics of clinic attenders; clinical diagnoses of STD; risk factors associated with HIV-1 and HIV-2 positivity. RESULTS: The overall prevalence of HIV (HIV-1 and/or HIV-2) infection was 21% (250 out of 1169; 16% HIV-1, 2% HIV-2, 3% dual reactivity). Overall prevalence varied by clinic: University Hospital Dermatology outpatients clinic, 39%; Clinic T, 19%; Clinic A, 10%. Men with STD had an overall prevalence of 31% (155 out of 506), compared with 14% in men without physical signs of STD (odds ratio 2.6, 95% confidence interval 2.0-3.6). The highest prevalence, 46%, was in men with genital ulcer disease. Risk factors associated with HIV-1 as well as with HIV-2 infection after multivariate analysis were a history of sex with prostitutes, lack of circumcision, being unskilled, and a history of prior genital ulcer. Current genital ulcer, current STD and positive Treponema pallidum haemagluttination assay were associated with HIV-1 and dual reactivity. CONCLUSIONS: Risk factors for HIV-2 infection in men attending Abidjan STD clinics were broadly similar to those for HIV-1 infection. HIV-1 infection was more strongly associated with current STD. Important differences between the three clinics were observed in STD prevalence and type, and HIV seroprevalence. Such differences should be taken into account in the planning of HIV serosurveillance in STD clinics.

Plasma osteocalcin concentrations in cattle under various pathophysiological conditions.

Plasma osteocalcin (BGP) concentrations were measured using an homologous radioimmunoassay in plasma samples (n = 6-14 per group) from fetal and newborn calves, 16-month-old heifers and bulls, and pregnant lactating cows. The highest values (nM) (62 +/- 3) were measured in fetal calves and the lowest (15 +/- 3) in 9-year-old pregnant and lactating cows. No significant relationship could be demonstrated between plasma BGP and somatomedin C, or 1,25(OH)2D or calcium concentrations. In eight normally calving cows, parturition was followed by a progressive increase in plasma BGP concentration, maximum 3 days after calving. It returned to prepartum values 10 days later. In six parturient hypocalcaemic and paretic cows, hypocalcaemia occurring within 12 h following calving was associated with a prompt and very transient increase in plasma BGP concentrations. These results indicate that osteocalcin might play a role in the regulation of bone metabolism in cattle.

[Intra- and extra-pelvic venous connections. Anatomical study]. / Connexions veineuses intra et extra-pelviennes. Etude anatomique.

Regarding to clinical diseases, the authors emphasize the important part of pelvic veins as collateral flows when iliac channels are occluded. They point out the three mains streams of this collateral network: the obturator veins, the gluteal veins, and the pudendal veins. Longitudinal anastomoses are connected each other by transversal veins such as Santorini plexus, and sacral veins; they allow venous supply from one side to the other when two levels or more are involved.

Antibiotic release from an experimental biodegradable bone cement.

An experimental biodegradable bone cement [poly(propylene fumarate)-methylmethacrylate] (PPF-MMA) has been compared in vivo with polymethylmethacrylate (PMMA) as a carrier agent for local release of antibiotics. This approach is potentially applicable to the treatment of chronic osteomyelitis where the clinical goal is to achieve sustained high concentrations of antibiotics locally in the infected bone. In our experiments, gentamicin- and vancomycin-impregnated cylindrical PMMA and PPF-MMA cement specimens were implanted subcutaneously in rats, and blood and wound fluid samples were obtained over a 2-week period. Antibiotic levels were determined using immunoassays, and microbiologic activity was confirmed with agar diffusion techniques. The biodegradable PPF-MMA cement achieved and maintained considerably higher wound antibiotic levels than did PMMA cement. Vancomycin levels for the PPF-MMA cement were greater than 20 times those for the PMMA cement at all sampling times from 24 h to 14 days. For both cements, the serum antibiotic concentrations remained safely below maximum levels recommended for parenteral therapy. Mechanical testing of the PPF-MMA cement showed that admixture of 3% by weight of antibiotic did not adversely affect material properties. We conclude that this experimental biodegradable bone cement (PPF-MMA) can be used as a carrier to achieve high sustained local levels and low serum levels of antibiotics. Because it is biodegradable and thus does not require a secondary procedure for removal, it has special potential for use in treatment of chronic osteomyelitis.

Effects of knee flexion on the structural properties of the rabbit femur-anterior cruciate ligament-tibia complex (FATC).

Many studies have been conducted to determine the biomechanical properties of the anterior cruciate ligament (ACL). The method of holding the femur-ACL-tibia complex (FATC) test specimen, the strain rate applied, the angle of knee flexion and the direction of the applied loads have an important effect on the outcome. It is felt that the tensile properties and strength of the ligament should be measured by applying the tensile force along the axis of the ligament. A versatile clamp was designed to accomplish this purpose. Fifty-seven rabbit knee specimens were tested at angles of flexion of 0 degrees, 30 degrees or 90 degrees. In addition, a comparative study of 25 pairs of rabbit legs were performed, whereby loading was either along the ligament or along the tibial axis. Cyclic hysteresis, ultimate load, energy absorbed, and stiffness were determined. The ultimate load values for the FATC decreased with increased knee flexion for those loaded along the tibial axis, while no such change was detected for FATC tested along the ligament axis. Other structural properties measured followed similar trends. It is concluded that the structural properties of the rabbit FATC change minimally with knee flexion (from 0 to 90 degrees) when loaded along the ligament axis, but decrease significantly with knee flexion when loaded along the axis of the tibia. Therefore, the data obtained in this field of study can be compared only if the direction of loading with respect to the ACL is similar.

Structural behavior of the halo orthosis pin-bone interface: biomechanical evaluation of standard and newly designed stainless steel halo fixation pins.

The structural response of the halo orthosis pin-bone interface to transverse loading was evaluated on an Instron testing machine using fresh cadaver calvarium sections. Commercially available stainless steel (control) pins and newly designed stainless steel experimental pins were evaluated. Cyclic loading tests and load-to-failure tests were performed. Of the many designs tested, one pin demonstrated an improvement in structural properties at the pin-bone interface compared with the control pin. Furthermore, the new pin design was more resistant to insertional torque reduction when subjected to cyclic loading after insertions at 4 and 6 in-lb. Both the control and experimental pins exhibited improved structural behavior at 8 in-lb of insertional torque compared to the currently recommended 6 in-lb.

Intrapericardial teratoma in infancy: a rare disease.

Intrapericardial teratoma is a rare, and generally benign, tumor originating from the 3 germinal layers. It occurs in 60% of the cases in the first two years of life. Severe cardio-respiratory distress due to mediastinal compression and pericardial effusion are the main clinical symptoms. Echo-cardiography and cine-angiography confirm the diagnosis and early surgical removal brings immediate and durable improvement.