Final Measurement of the

This Letter reports one of the most precise measurements to date of the antineutrino spectrum from a purely ^{235}U-fueled reactor, made with the final dataset from the PROSPECT-I detector at the High Flux Isotope Reactor. By extracting information from previously unused detector segments, this analysis effectively doubles the statistics of the previous PROSPECT measurement. The reconstructed energy spectrum is unfolded into antineutrino energy and compared with both the Huber-Mueller model and a spectrum from a commercial reactor burning multiple fuel isotopes. A local excess over the model is observed in the 5-7 MeV energy region. Comparison of the PROSPECT results with those from commercial reactors provides new constraints on the origin of this excess, disfavoring at 2.0 and 3.7 standard deviations the hypotheses that antineutrinos from ^{235}U are solely responsible and noncontributors to the excess observed at commercial reactors, respectively.

Joint Determination of Reactor Antineutrino Spectra from

A joint determination of the reactor antineutrino spectra resulting from the fission of ^{235}U and ^{239}Pu has been carried out by the Daya Bay and PROSPECT Collaborations. This Letter reports the level of consistency of ^{235}U spectrum measurements from the two experiments and presents new results from a joint analysis of both data sets. The measurements are found to be consistent. The combined analysis reduces the degeneracy between the dominant ^{235}U and ^{239}Pu isotopes and improves the uncertainty of the ^{235}U spectral shape to about 3%. The ^{235}U and ^{239}Pu antineutrino energy spectra are unfolded from the jointly deconvolved reactor spectra using the Wiener-SVD unfolding method, providing a data-based reference for other reactor antineutrino experiments and other applications. This is the first measurement of the ^{235}U and ^{239}Pu spectra based on the combination of experiments at low- and highly enriched uranium reactors.

Joint Measurement of the

The PROSPECT and STEREO collaborations present a combined measurement of the pure ^{235}U antineutrino spectrum, without site specific corrections or detector-dependent effects. The spectral measurements of the two highest precision experiments at research reactors are found to be compatible with χ^{2}/ndf=24.1/21, allowing a joint unfolding of the prompt energy measurements into antineutrino energy. This ν[over ¯]_{e} energy spectrum is provided to the community, and an excess of events relative to the Huber model is found in the 5-6 MeV region. When a Gaussian bump is fitted to the excess, the data-model χ^{2} value is improved, corresponding to a 2.4σ significance.

Measurement of the Antineutrino Spectrum from

This Letter reports the first measurement of the ^{235}U ν[over ¯]_{e} energy spectrum by PROSPECT, the Precision Reactor Oscillation and Spectrum experiment, operating 7.9 m from the 85 MW_{th} highly enriched uranium (HEU) High Flux Isotope Reactor. With a surface-based, segmented detector, PROSPECT has observed 31678±304(stat) ν[over ¯]_{e}-induced inverse beta decays, the largest sample from HEU fission to date, 99% of which are attributed to ^{235}U. Despite broad agreement, comparison of the Huber ^{235}U model to the measured spectrum produces a χ^{2}/ndf=51.4/31, driven primarily by deviations in two localized energy regions. The measured ^{235}U spectrum shape is consistent with a deviation relative to prediction equal in size to that observed at low-enriched uranium power reactors in the ν[over ¯]_{e} energy region of 5-7 MeV.

First Search for Short-Baseline Neutrino Oscillations at HFIR with PROSPECT.

This Letter reports the first scientific results from the observation of antineutrinos emitted by fission products of ^{235}U at the High Flux Isotope Reactor. PROSPECT, the Precision Reactor Oscillation and Spectrum Experiment, consists of a segmented 4 ton ^{6}Li-doped liquid scintillator detector covering a baseline range of 7-9 m from the reactor and operating under less than 1 m water equivalent overburden. Data collected during 33 live days of reactor operation at a nominal power of 85 MW yield a detection of 25 461±283 (stat) inverse beta decays. Observation of reactor antineutrinos can be achieved in PROSPECT at 5σ statistical significance within 2 h of on-surface reactor-on data taking. A reactor model independent analysis of the inverse beta decay prompt energy spectrum as a function of baseline constrains significant portions of the previously allowed sterile neutrino oscillation parameter space at 95% confidence level and disfavors the best fit of the reactor antineutrino anomaly at 2.2σ confidence level.

[Characteristics of elective hip replacement in the elderly]. / Besonderheiten beim elektiven Hüftgelenkersatz des älteren Menschen.

Due to demographic changes the number of elderly patients undergoing hip replacement surgery is increasing. In order to ensure safe treatment of elderly patients, age-specific medical factors must be taken into consideration. This article presents an overview of these factors. Furthermore, we evaluated our own patients treated between 2010 and 2015 regarding age-related treatment strategies and complication rates. Out of 3166 patients a total of 439 were over 80 years old (average age 84 years). It can be concluded from the scientific literature and from own data that elective hip replacement surgery in elderly patients is a technically safe procedure; however, the risk profile of each patient must be thoroughly analyzed so that in the event of even minor signs of potential complications countermeasures can be taken in good time.

Bilateral hip imaging at 7 Tesla using a multi-channel transmit technology: initial results presenting anatomical detail in healthy volunteers and pathological changes in patients with avascular necrosis of the femoral head.

OBJECTIVE: To evaluate 7-T MRI of both hips using a multi-channel transmit technology to compensate for inherent B1 inhomogeneities in volunteers and patients with avascular necrosis of the femoral head. MATERIALS AND METHODS: A self-built, eight-channel transmit-receive coil was utilized for B1 modification at 7 T. Two shim modes (individual shim vs. CP2+ mode) were initially compared and the best shim result was used for all further imaging. Robustness of sequences against B1 inhomogeneities, appearance of anatomic and pathologic changes of the femoral heads of MEDIC, DESS, PD/T2w TSE, T1w TSE, and STIR sequences at 7 T were evaluated in 12 subjects on a four-point scale (1-4): four male volunteers and eight patients (seven males, one female) suffering from avascular necrosis treated by advanced core decompression. RESULTS: Successful MRI of both femoral heads was achieved in all 12 subjects. CP2+ mode proved superior in ten of 12 cases. DESS proved most robust against B1 inhomogeneity. Anatomical details (labrum, articular cartilage) were best depicted in PDw, MEDIC, and DESS, while for depiction of pathological changes PDw, DESS (0.76 mm(3)) and T1w were superior. CONCLUSIONS: Our initial results of ultra-high-field hip joint imaging demonstrate high-resolution, high-contrast images with a good depiction of anatomic and pathologic changes. However, shifting areas of signal dropout from the femoral heads to the center of the pelvis makes these areas not assessable. For clinical workflow CP2+ mode is most practical. Seven-Tesla MRI of the hip joints may become a valuable complement to clinical field strengths.

Indication of reactor ν(e) disappearance in the Double Chooz experiment.

The Double Chooz experiment presents an indication of reactor electron antineutrino disappearance consistent with neutrino oscillations. An observed-to-predicted ratio of events of 0.944±0.016(stat)±0.040(syst) was obtained in 101 days of running at the Chooz nuclear power plant in France, with two 4.25 GW(th) reactors. The results were obtained from a single 10 m(3) fiducial volume detector located 1050 m from the two reactor cores. The reactor antineutrino flux prediction used the Bugey4 flux measurement after correction for differences in core composition. The deficit can be interpreted as an indication of a nonzero value of the still unmeasured neutrino mixing parameter sin(2)2θ(13). Analyzing both the rate of the prompt positrons and their energy spectrum, we find sin(2)2θ(13)=0.086±0.041(stat)±0.030(syst), or, at 90% C.L., 0.017

Experimental investigation of geologically produced antineutrinos with KamLAND.

The detection of electron antineutrinos produced by natural radioactivity in the Earth could yield important geophysical information. The Kamioka liquid scintillator antineutrino detector (KamLAND) has the sensitivity to detect electron antineutrinos produced by the decay of 238U and 232Th within the Earth. Earth composition models suggest that the radiogenic power from these isotope decays is 16 TW, approximately half of the total measured heat dissipation rate from the Earth. Here we present results from a search for geoneutrinos with KamLAND. Assuming a Th/U mass concentration ratio of 3.9, the 90 per cent confidence interval for the total number of geoneutrinos detected is 4.5 to 54.2. This result is consistent with the central value of 19 predicted by geophysical models. Although our present data have limited statistical power, they nevertheless provide by direct means an upper limit (60 TW) for the radiogenic power of U and Th in the Earth, a quantity that is currently poorly constrained.

Nonfuel Antineutrino Contributions in the High Flux Isotope Reactor.

Reactor neutrino experiments have seen major improvements in precision in recent years. With the experimental uncertainties becoming lower than those from theory, carefully considering all sources of ν ¯ e is important when making theoretical predictions. One source of ν ¯ e that is often neglected arises from the irradiation of the nonfuel materials in reactors. The ν ¯ e rates and energies from these sources vary widely based on the reactor type, configuration, and sampling stage during the reactor cycle and have to be carefully considered for each experiment independently. In this article, we present a formalism for selecting the possible ν ¯ e sources arising from the neutron captures on reactor and target materials. We apply this formalism to the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, the ν ¯ e source for the the Precision Reactor Oscillation and Spectrum Measurement (PROSPECT) experiment. Overall, we observe that the nonfuel ν ¯ e contributions from HFIR to PROSPECT amount to 1% above the inverse beta decay threshold with a maximum contribution of 9% in the 1.8-2.0 MeV range. Nonfuel contributions can be particularly high for research reactors like HFIR because of the choice of structural and reflector material in addition to the intentional irradiation of target material for isotope production. We show that typical commercial pressurized water reactors fueled with low-enriched uranium will have significantly smaller nonfuel ν ¯ e contribution.

[Modification of the method of Figgie for determination of joint line shifting in total knee arthroplasty]. / Modifizierung der Messmethode nach Figgie zur Bestimmung der Gelenklinienverschiebung in der Knieendoprothetik.

An important factor for a good result after total knee arthroplasty is the position of the patella in relation to the tibiofemoral joint line. The position of the patella itself is not influenced by arthroplasty, therefore any changes in the position of the tibiofemoral joint line are of special interest. The Figgie method to describe patella height delivers only absolute measurements, which makes it difficult to compare different radiographs. For this reason we developed a new JL/P quotient (JL: distance from the tibial plateau to the tibial tubercle, P: distance from the inferior pole of the patella to the tibial plateau) to enable better comparison. Furthermore, we modified the JL/P quotient and instead of taking the tibial plateau as the reference line, we constructed a tangent on the femoral condyle. With this modification, problems such as tibial inlays of different heights which have to be taken into account in the measurements, the slope of the tibial component or difficult assessment of the tibial joint surface in osteoarthritic knees do not arise. The JL/P quotient shows massive shift to cranialisation of the tibiofemoral joint line which does not correspond to reality. The modified method also shows cranialisation of the tibiofemoral joint line, but in a realistic way. Both methods show a minimal interobserver variability. The modified JL/P quotient seems to be a good method for determining the shift in the tibiofemoral joint line after total knee arthroplasty.

[Modification of the Blackburne-Peel ratio for improved application in total knee arthroplasty]. / Modifizierung des Blackburne-Peel-Index zur besseren Anwendung in der Knieendoprothetik.

BACKGROUND: The methods currently used to measure patella height in relation to the tibiofemoral joint line after total knee arthroplasty are not easily reproducible. For this reason we modified the Blackburne-Peel ratio. MATERIALS AND METHODS: Instead of taking the tibial joint line as the reference line, we constructed a tangent on the femoral condyle. In addition, we took the greatest diameter of the patella from the tip of the patella as a measuring line. RESULTS: Compared with the classic Blackburne-Peel and Caton-Deschamps ratios, it was much easier to determine the patella height in osteoarthritic knees and after total knee replacement using this modified Blackburne-Peel ratio. Factors such as the height of the polyethylene inlay, the slope of the tibial component, and superimposition of the patellar joint line can be disregarded. Preoperative and postoperative reference lines can be compared readily. Furthermore, the classic Blackburne-Peel ratio shows a greater tendency to interpret the measurements after total knee arthroplasty as pseudo-patella baja. The interobserver variability was good for all ratios. CONCLUSION: We can therefore recommend the modified Blackburne-Peel ratio for measuring patella height in relation to the tibiofemoral joint line after total knee arthroplasty.

Comparison of two different designs of forefoot off-loader shoes and their influence on gait and spinal posture.

BACKGROUND: The purpose of forefoot off-loader shoes (FOS) is to unload the operated region of the foot in order to allow early mobilization and rehabilitation. However, little is known about the actual biomechanical effects of different designs of FOS on gait, pelvis and spine. RESEARCH QUESTION: Aim of this study was to analyse and compare the effects of two different designs of forefoot unloader shoes. METHODS: Ortho-Wedge (FOS A) and Relief-Dual® (FOS B) were evaluated in this study during standing and while walking. Changes of the pelvic position and spinal posture were measured with a surface topography system and an instrumented treadmill. Gait phases were detected automatically by a built-in pressure plate. RESULTS: Both FOS resulted in a significant increase of pelvic obliquity, pelvic torsion, lateral deviation and surface rotation (p < 0.001) while standing. Between both shoe models, pelvic obliquity and lateral deviation (p < 0.05) were significantly different. During walking, both FOS had a significant effect on spine and pelvis (p < 0.05), however only minor differences were found between the designs. All gait parameters were affected more, wearing FOS A than B. Step length were significantly longer by wearing FOS (p < 0.005). However stance phase raised and swing phase is reduced on the leg wearing FOS A (p < 0.001). SIGNIFICANCE: The study showed that FOS lead to significant changes in pelvic position and spinal posture during standing and while walking. A compensating shoe on the contralateral side is therefore recommend. Gait parameters however were affected more by the traditional FOS A half-shoe. The sole- design and shape of FOS B leads to a more physiological roll-over of the foot.

Laccase isoform diversity in basidiomycete Lentinus strigosus 1566: Potential for phenylpropanoid polymerization.

Three laccase isoforms with different physicochemical properties could be purified from culture liquid of basidiomycete Lentinus strigosus 1566 obtained during submerged cultivation. The purified laccases possessed individual selectivity in relation to different phenolic compounds. Laccases I, II, and III (59, 65, and 61 kDa respectively) were more active in acidic conditions at around 70 °C. However, in contrast to laccases I and II, laccase III retained its activity (8-30%) and stability during at least one week of incubation at neutral conditions that allows its biotechnological application carried out at neutral environment. The activation phenomena for some of the purified laccases from L. strigosus 1566 during incubation at high temperature, different pH, and sulfates is shown and discussed. According to MALDI-TOF analysis, laccases I and II are most closely related to the laccase of Panus rudis (AAR13230). Transformation of phenylpropanoids by the predominant laccases of L. strigosus 1566 to different polymers was demonstrated, indicating a great potential for producing novel pharmaceutical valuable analogues of lignans, stilbenes, flavonoids, and etc.. The studied laccases, which are products of the same strain, can become a convenient model for further studies of the structural mechanisms of the shift of T-/pH-optima, activation, and T-/pH-stability.

Functional interest of an articulating spacer in two-stage infected total knee arthroplasty revision.

INTRODUCTION: Deep periprosthetic infection is one of the most serious complications after total knee replacement. The two-stage procedure with implantation of a temporary cement spacer and later re-implantation of a revision total knee prosthesis is an accepted procedural standard. The use of articulating spacers has been proposed to enhance ease of revision and functional results. PATIENTS AND METHODS: Twenty-three patients treated with an articulating spacer were retrospectively studied. All patients had undergone a two-stage surgery. The infected prosthesis was explanted and the femoral component was sterilized and re-implanted. On the tibial side a block of gentamicin-loaded bone cement was produced intraoperatively using specially manufactured templates. Eighteen total knee arthroplasty revisions and 5 arthrodesis were finally performed. RESULTS: A total of three (13%) re-infections occurred 5-20 months after revision total knee arthroplasty in a mean follow-up period of 47 months. Prior to re-implantation, flexion with the articulating spacer ranged between 15 and 100° (mean 68±28°). The average postoperative flexion after re-implantation of total knee replacement was 105±11°. CONCLUSION: The articulating spacer used in this study appears to be as effective as the standard procedures in terms of re-infection risk rate and postoperative range of motion recovery. LEVEL OF EVIDENCE: Level IV.

Experimental and computational studies on the femoral fracture risk for advanced core decompression.

BACKGROUND: Two questions are often addressed by orthopedists relating to core decompression procedure: 1) Is the core decompression procedure associated with a considerable lack of structural support of the bone? and 2) Is there an optimal region for the surgical entrance point for which the fracture risk would be lowest? As bioresorbable bone substitutes become more and more common and core decompression has been described in combination with them, the current study takes this into account. METHODS: Finite element model of a femur treated by core decompression with bone substitute was simulated and analyzed. In-vitro compression testing of femora was used to confirm finite element results. FINDINGS: The results showed that for core decompression with standard drilling in combination with artificial bone substitute refilling, daily activities (normal walking and walking downstairs) are not risky for femoral fracture. The femoral fracture risk increased successively when the entrance point is located further distal. The critical value of the deviation of the entrance point to a more distal part is about 20mm. INTERPRETATION: The study findings demonstrate that optimal entrance point should locate on the proximal subtrochanteric region in order to reduce the subtrochanteric fracture risk. Furthermore the consistent results of finite element and in-vitro testing imply that the simulations are sufficient.

[Accuracy of rotational positioning of the femoral component using the tibial-cut-first technique]. / Bestimmung der Rotationsgenauigkeit der Femurkomponente bei Tibial-Cut-First-Technik.

AIM: Problems with the patellofemoral joint are still one of the most common difficulties after total knee arthroplasty. One of the main reasons for these problems seems to be the rotatory malposition of the femoral component. We examined the rotation of the femoral component and the symmetry of the flexion gap of knee prostheses implanted using the tibial-cut-first technique. METHOD: The radiographs of 58 consecutive patients who underwent primary LCS total knee arthroplasty in 2008 were examined retrospectively. The rotation of the femoral component was determined intraoperatively using the femoral positioner and depended on the amount of tibial resection and the tension of the collateral ligaments. The position was then checked by means of three anatomic landmarks: the epicondylar axis, the posterior condyles and the Whiteside line. We used Kanekasu's technique for the radiographs. With this technique it was possible to ascertain the rotation of the femoral component after total knee arthroplasty easily and with a low level of radiation. It was also possible to determine the opening of the flexion gap. RESULTS: The radiographs showed a slight external rotation of the femoral component of 1.31°. The opening of the flexion gap was increased laterally, but only by 1.5°. CONCLUSION: In this study, determination of femoral rotation using the tibial-cut-first technique resulted in a slight external rotation of the femoral component. Furthermore, it is possible to create an almost symmetrical flexion gap with this method.

Precision measurement of neutrino oscillation parameters with KamLAND.

The KamLAND experiment has determined a precise value for the neutrino oscillation parameter Deltam21(2) and stringent constraints on theta12. The exposure to nuclear reactor antineutrinos is increased almost fourfold over previous results to 2.44 x 10(32) proton yr due to longer livetime and an enlarged fiducial volume. An undistorted reactor nu[over]e energy spectrum is now rejected at >5sigma. Analysis of the reactor spectrum above the inverse beta decay energy threshold, and including geoneutrinos, gives a best fit at Deltam21(2)=7.58(-0.13)(+0.14)(stat) -0.15+0.15(syst) x 10(-5) eV2 and tan2theta12=0.56(-0.07)+0.10(stat) -0.06+0.10(syst). Local Deltachi2 minima at higher and lower Deltam21(2) are disfavored at >4sigma. Combining with solar neutrino data, we obtain Deltam21(2)=7.59(-0.21)+0.21 x 10(-5) eV2 and tan2theta12=0.47(-0.05)+0.06.

Search for the invisible decay of neutrons with KamLAND.

The Kamioka Liquid scintillator Anti-Neutrino Detector is used in a search for single neutron or two-neutron intranuclear disappearance that would produce holes in the -shell energy level of (12)C nuclei. Such holes could be created as a result of nucleon decay into invisible modes (inv), e.g., n--> 3v or nn--> 2v. The deexcitation of the corresponding daughter nucleus results in a sequence of space and time-correlated events observable in the liquid scintillator detector. We report on new limits for one- and two-neutron disappearance: tau(n--> inv) > 5.8 x 10(29) years and tau (nn--> inv) > 1.4 x 10(30) years at 90% C.L. These results represent an improvement of factors of approximately 3 and >10(4) and over previous experiments.

Measurement of neutrino oscillation with KamLAND: evidence of spectral distortion.

We present results of a study of neutrino oscillation based on a 766 ton/year exposure of KamLAND to reactor antineutrinos. We observe 258 nu (e) candidate events with energies above 3.4 MeV compared to 365.2+/-23.7 events expected in the absence of neutrino oscillation. Accounting for 17.8+/-7.3 expected background events, the statistical significance for reactor nu (e) disappearance is 99.998%. The observed energy spectrum disagrees with the expected spectral shape in the absence of neutrino oscillation at 99.6% significance and prefers the distortion expected from nu (e) oscillation effects. A two-neutrino oscillation analysis of the KamLAND data gives Deltam(2)=7.9(+0.6)(-0.5)x10(-5) eV(2). A global analysis of data from KamLAND and solar-neutrino experiments yields Deltam(2)=7.9(+0.6)(-0.5)x10(-5) eV(2) and tan((2)theta=0.40(+0.10)(-0.07), the most precise determination to date.