First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment.

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9 GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36 GeV/c^{2}, rejecting cross sections above 9.2×10^{-48} cm at the 90% confidence level.

The impact of accuracy and precision of analytical test methods on the determination of withdrawal periods.

Treatment of food-producing animals with veterinary medicinal products (VMPs) can result in residues in foodstuffs (e.g. eggs, meat, milk, or honey) representing a potential consumer health risk. To ensure consumer safety, worldwide regulatory concepts for setting safe limits for residues of VMPs e.g. as tolerances (US) or maximum residue limits (MRLs, EU) are used. Based on these limits so-called withdrawal periods (WP) are determined. A WP represents the minimum period of time required between the last administration of the VMP and the marketing of foodstuff. Usually, WPs are estimated using regression analysis based on residue studies. With high statistical confidence (usually 95% in the EU and 99% in the US) the residues in almost all treated animals (usually 95%) have to be below MRL when edible produce is harvested. Here, uncertainties from both sampling and biological variability are taken into account but uncertainties of measurement associated with the analytical test methods are not systematically considered. This paper describes a simulation experiment to investigate the extent to which relevant sources of measurement uncertainty (accuracy and precision) can impact the length of WPs. A set of real residue depletion data was artificially 'contaminated' with measurement uncertainty related to permitted ranges for accuracy and precision. The results show that both accuracy and precision had a noticeable effect on the overall WP. Due consideration of sources of measurement uncertainty may improve the robustness, quality and reliability of calculations upon which regulatory decisions on consumer safety of residues are based.

Impact of growth kinetics on the interface morphology and magnetization in La1/3Sr2/3FeO3/La2/3Sr1/3MnO3 heterostructures.

The ability to create atomically perfect, epitaxial heterostructures of correlated complex perovskite oxides using state-of-art thin film deposition techniques has generated new physical phenomena at engineered interfaces. Here we report on the impact of growth kinetics on the magnetic structure and exchange coupling at the interface in heterostructures combining layers of antiferromagnetic La1/3Sr2/3FeO3 (LSFO) and ferromagnetic La2/3Sr1/3MnO3 (LSMO) on (0 0 1)-oriented SrTiO3 (STO) substrates. Two growth orders are investigated, (a) LSMO/LSFO/STO(0 0 1) and (b) LSFO/LSMO/STO(0 0 1), where the LSFO layer is grown by molecular beam epitaxy and the LSMO layer by high oxygen pressure sputtering. The interface has been investigated using electron microscopy and polarized neutron reflectometry. Interdiffusion over seven monolayers is observed in LSMO/LSFO (a) with an almost 50% reduction in magnetization at the interface and showing no exchange coupling. However, the exchange bias effect ([Formula: see text] mT at 10 K) could be realized when the interface is atomically sharp, as in LSFO/LSMO (b). Our study therefore reveals that, even for well ordered and lattice-matched structures, the kinetics involved in the growth processes drastically influences the interface quality with a strong correlation to the magnetic properties.

[Detection of malnutrition in geriatric trauma patients : A reassessment]. / Erfassung von Mangelernährung bei geriatrischen Traumapatienten : Eine erneute Bestandsaufnahme.

BACKGROUND AND OBJECTIVE: Malnutrition in geriatric trauma patients is associated with an increased risk of complications and mortality and is therefore a key risk factor. The assessment of the affected patients plays an important role in improving the outcome of this growing patient group. MATERIAL AND METHODS: In 2016 a questionnaire was sent to 571 departments specialized in traumatology and orthopedics throughout Germany. The following were recorded: level of care, expertise in geriatric trauma, nutrition-based screening procedures and nutritional ward round procedures. RESULTS: The response rate was 57% (n = 325) and closely reflected the treatment reality in Germany with respect to the level of care (superregional, regional or local trauma center and those without special qualifications). In 14% (n = 45) the participants were German Society for Trauma Surgery(DGU)-certified centers for age-related traumatology, while a further 5% (n = 15) were in the process of certification. The nutritional status was assessed in 56% (n = 181) of the clinics. Most frequently used was the body mass index (74%) followed by the mini nutritional assessment (30%), laboratory parameters (29%) and nutritional risk screening 2002 (19%). Some additional methods were specified. In approximately half of the departments nutritional ward rounds took place in regular wards (50%) and intensive care units (57%). DISCUSSION: The high response rate of this study seems to show the particular interest for malnutrition in geriatric trauma patients. This is reflected in an increase in the participating clinics compared to past surveys and also the more regularly performed assessment of nutritional status and implementation of nutritional visits. CONCLUSION: The establishment of suitable and time-effective screening instruments and their implementation are still a challenge.

Dr. Probe: A software for high-resolution STEM image simulation.

The Dr. Probe software for multislice simulations of STEM images is introduced, and reference is given of the applied methods. Major program features available with the graphical user interface version are demonstrated by means of a few examples for bright-field and dark-field STEM imaging as well as simulations of diffraction patterns. The numerical procedure applied for the simulation of thermal-diffuse scattering by the frozen-lattice approach is described in detail. Intensity variations occurring in simulations with atomic-column resolution due to frozen-lattice variations are discussed in the context of atom counting. It is found that a significant averaging over many lattice configurations with different random atomic displacements is required to prevent atom-counting bias from simulations. A strategy is developed for the assessment of the amount of required averaging based on the estimated signal variance and the expected signal gain per atom in a column.

One year after proximal or distal periprosthetic fracture of the femur -two conditions with divergent outcomes?

INTRODUCTION: Arthroplasty of the hip and knee is 1 of the 20 most frequent operations in Germany. Periprosthetic fracture is one of the most feared complications following primary or revision arthroplasty. Present publication aims to analyse differences between patients with periprosthetic fracture around total knee arthroplasty (PFTKA) and patients with periprosthetic fracture around total hip arthroplasty (PFTHA) concerning demographics, clinical course, complications and return to pre-fracture mobility. METHODS: Prospective single-centre observation study of periprosthetic femoral fractures with stable implants. Present subgroup analysis includes patients with PFTKA and PFTHA. All patients were treated with polyaxial angular stable plates using two standardized techniques: a minimally invasive percutaneous distal insertion technique and a mini-open technique. Data collection included implant- and operation-related information as well as demographics, clinical course, complications and return to pre-fracture mobility. Data were collected during a 12-month follow-up. RESULTS: We were able to analyse the data of 73 patients. The PFTKA group had 37 patients with a mean age of 76 ±â€¯10 years; 88% were female. After 1 year, 3 patients in this cohort had died; 68% of survivors had reached their pre-fracture mobility; 22% had undergone operative revisions for various reasons. The PFTHA cohort included 36 patients with a mean age of 80 ±â€¯13 years, 72% were female. After 1 year, 9 patients had died in this cohort, 42% of survivors had reached their pre-fracture mobility. Non-operative complications occurred for 16% in the PFTKA group and 64% in the PFTHA group (p < 0.001). 11% had undergone operative revisions for various reasons, among them, two cases of nonunion but no primary infection. CONCLUSION: On average, compared to the PFTHA patients, PFTKA patients were younger, underwent significantly lower rates of non-operative complications, had a tendency towards lower mortality, and returned to pre-fracture mobility at higher rates, although they tended to have more revisions when compared to treatment for PFTHA. Overall, when periprosthetic fractures of the femur were treated using polyaxial locking plate osteosynthesis, patients showed very low rates of nonunion and no primary infection.

Atomic resolution elemental mapping using energy-filtered imaging scanning transmission electron microscopy with chromatic aberration correction.

This paper addresses a novel approach to atomic resolution elemental mapping, demonstrating a method that produces elemental maps with a similar resolution to the established method of electron energy-loss spectroscopy in scanning transmission electron microscopy. Dubbed energy-filtered imaging scanning transmission electron microscopy (EFISTEM) this mode of imaging is, by the quantum mechanical principle of reciprocity, equivalent to tilting the probe in energy-filtered transmission electron microscopy (EFTEM) through a cone and incoherently averaging the results. In this paper we present a proof-of-principle EFISTEM experimental study on strontium titanate. The present approach, made possible by chromatic aberration correction, has the advantage that it provides elemental maps which are immune to spatial incoherence in the electron source, coherent aberrations in the probe-forming lens and probe jitter. The veracity of the experiment is supported by quantum mechanical image simulations, which provide an insight into the image-forming process. Elemental maps obtained in EFTEM suffer from the effect known as preservation of elastic contrast, which, for example, can lead to a given atomic species appearing to be in atomic columns where it is not to be found. EFISTEM very substantially reduces the preservation of elastic contrast and yields images which show stability of contrast with changing thickness. The experimental application is demonstrated in a proof-of-principle study on strontium titanate.

Quantitative Agreement between Electron-Optical Phase Images of WSe_{2} and Simulations Based on Electrostatic Potentials that Include Bonding Effects.

The quantitative analysis of electron-optical phase images recorded using off-axis electron holography often relies on the use of computer simulations of electron propagation through a sample. However, simulations that make use of the independent atom approximation are known to overestimate experimental phase shifts by approximately 10%, as they neglect bonding effects. Here, we compare experimental and simulated phase images for few-layer WSe_{2}. We show that a combination of pseudopotentials and all-electron density functional theory calculations can be used to obtain accurate mean electron phases, as well as improved atomic-resolution spatial distribution of the electron phase. The comparison demonstrates a perfect contrast match between experimental and simulated atomic-resolution phase images for a sample of precisely known thickness. The low computational cost of this approach makes it suitable for the analysis of large electronic systems, including defects, substitutional atoms, and material interfaces.

Surface reconstructions and related local properties of a BiFeO3 thin film.

Coupling between lattice and order parameters, such as polarization in ferroelectrics and/or polarity in polar structures, has a strong impact on surface relaxation and reconstruction. However, up to now, surface structures that involve the termination of both matrix polarization and polar atomic planes have received little attention, particularly on the atomic scale. Here, we study surface structures on a BiFeO3 thin film using atomic-resolution scanning transmission electron microscopy and spectroscopy. Two types of surface structure are found, depending on the polarization of the underlying ferroelectric domain. On domains that have an upward polarization component, a layer with an Aurivillius-Bi2O2-like structural unit is observed. Dramatic changes in local properties are measured directly below the surface layer. On domains that have a downward polarization component, no reconstructions are visible. Calculations based on ab initio density functional theory reproduce the results and are used to interpret the formation of the surface structures.

The role of perioperative blood transfusion on postoperative outcomes and overall survival in patients after laparoscopic radical cystectomy.

INTRODUCTION: There are different studies in the last decades focused on general surgery patients and the impact of perioperative blood transfusion (PBT) in cancer patients' survival, and most of them have supported an independent association between PBT and worse survival in those with solid tumor malignancies. The aim of this study is to evaluate the impact of perioperative blood transfusion on the postoperative outcomes and survival of patients after LRC. MATERIALS AND METHODS: We performed a retrospective study analyzing our series of 218 patients surgically treated with LRC form 2005 to 2012. One-way analysis of variance test was used. Survival was estimated using the Kaplan - Meier method and was compared with log - rank and the Cox regression model was used to evaluate the association of PBT with the outcomes. RESULTS: The PBT rate of LRC series was 16%. Patients' age, comorbidities and pathological stage were not related to the PBT rate. A statistically significant relationship was found between the PBT rate and the appearance of infectious complications. Overall 3 years survival estimated with the Kaplan-Meier method was significantly worse in the transfused group: 41.38% versus 63.57% for non-transfused patients. PBT was not a significant independent predictor factor in the survival of patients after LRC. The main independent factor was the TNM classification. CONCLUSIONS: Many studies including ours have reported a lower survival rate in patients who receive PBT after oncological surgery. There was a relationship between infectious complications and PBT. We have to make efforts to limit the use of blood products in patients surgically treated with radical cystectomy for bladder cancer.

Complex Nanotwin Substructure of an Asymmetric Σ9 Tilt Grain Boundary in a Silicon Polycrystal.

Grain boundaries in materials have substantial influences on device properties, for instance on mechanical stability or electronic minority carrier lifetime in multicrystalline silicon solar cells. This applies especially to asymmetric, less ordered or faceted interface portions. Here, we present the complex atomic interface structure of an asymmetric Σ9 tilt grain boundary in silicon, observed by high resolution scanning transmission electron microscopy (HR-STEM) and explained by atomistic modeling and computer simulation. Structural optimization of interface models for the asymmetric Σ9 and related symmetrical Σ9 and Σ3 tilt grain boundaries, by means of molecular-statics simulations with empirical silicon potentials in combination with first-principles calculations, results in a faceted asymmetric interface structure, whose grain-boundary energy is so low that it is likely to exist. The simulated local atomic structures match the observed HR-STEM images very well.

Determination of the 3D shape of a nanoscale crystal with atomic resolution from a single image.

Although the overall atomic structure of a nanoscale crystal is in principle accessible by modern transmission electron microscopy, the precise determination of its surface structure is an intricate problem. Here, we show that aberration-corrected transmission electron microscopy, combined with dedicated numerical evaluation procedures, allows the three-dimensional shape of a thin MgO crystal to be determined from only one single high-resolution image. The sensitivity of the reconstruction procedure is not only sufficient to reveal the surface morphology of the crystal with atomic resolution, but also to detect the presence of adsorbed impurity atoms. The single-image approach that we introduce offers important advantages for three-dimensional studies of radiation-sensitive crystals.

Oncological outcomes of nephron sparing nephrectomy. 17-year analysis.

OBJECTIVES: Nephron sparing renal surgery is considered the technique of choice for renal tumors smaller than 4 cm. We present our oncological results in a 17-year period. METHODS: Between January 1995 and December 2012, 130 renal tumor surgeries (58 open, 72 laparoscopic) were performed. We analize the pathological results, presence of positive surgical margins, local relapse, distant metastases and death. RESULTS: The most frequent tumor was clear cell carcinoma (73%) in a pT1 stage (87%). Mean tumor size was 3 cm. Positive surgical margin rate was 7%, currently without any tumor recurrence among these cases (follow up 37 months). Cancer specific mortality is 0% and local recurrence rate 3%. Mean follow up is 71 months. CONCLUSIONS: Nephron sparing surgery results are similar to radical nephrectomy in tumors smaller than 4 cm. Positive surgical margins do not seem to have an important repercussion in cancer specific survival.

Resultados oncológicos de la cirugía conservadora de parénquima renal. Análisis de 17 años / Oncological outcomes of nephron sparing nephrectomy. 17-year analysis

OBJETIVO: La cirugía renal conservadora de parénquima se considera la técnica de elección en tumores renales menores de 4 cm. Presentamos nuestros resultados oncológicos de un periodo de 17 años. MÉTODOS: Entre enero de 1995 y diciembre de 2012 se han realizado 130 cirugías renales por tumor (58 abiertas, 72 laparoscópicas). Analizamos los resultados anatomopatológicos, la presencia de márgenes positivos, recidiva local, metástasis a distancia y exitus. RESULTADOS: El tumor más frecuente es el de células claras (73%) en un estadio pT1 (87%). El tamaño medio tumoral es de 3,4 cm. La tasa de márgenes positivos es de 7%, sin recidiva tumoral en estos casos en la actualidad (seguimiento de 37 meses). La mortalidad cáncer específica es del 0% y la tasa de recidiva local es del 3%. El seguimiento medio es de 71 meses. CONCLUSIONES: La cirugía conservadora de parénquima tiene resultados superponibles a la nefrectomía radical en tumores por debajo de 4 cm. Los márgenes positivos no parecen tener una repercusión importante en la supervivencia cáncer específica

OBJECTIVES: Nephron sparing renal surgery is considered the technique of choice for renal tumors smaller than 4 cm. We present our oncological results in a 17-year period. METHODS: Between January 1995 and December 2012, 130 renal tumor surgeries (58 open, 72 laparoscopic) were performed. We analize the pathological results, presence of positive surgical margins, local relapse, distant metastases and death. RESULTS: The most frequent tumor was clear cell carcinoma (73%) in a pT1 stage (87%). Mean tumor size was 3 cm. Positive surgical margin rate was 7%, currently without any tumor recurrence among these cases (follow up 37 months). Cancer specific mortality is 0% and local recurrence rate 3%. Mean follow up is 71 months. CONCLUSIONS: Nephron sparing surgery results are similar to radical nephrectomy in tumors smaller than 4 cm. Positive surgical margins do not seem to have an important repercussion in cancer specific survival

On the optical stability of high-resolution transmission electron microscopes.

In the recent two decades the technique of high-resolution transmission electron microscopy experienced an unprecedented progress through the introduction of hardware aberration correctors and by the improvement of the achievable resolution to the sub-Ångström level. The important aspect that aberration correction at a given resolution requires also a well defined amount of optical stability has received little attention so far. Therefore we investigate the qualification of a variety of high-resolution electron microscopes to maintain an aberration corrected optical state in terms of an optical lifetime. We develop a comprehensive statistical framework for the estimation of the optical lifetime and find remarkably low values between tens of seconds and a couple of minutes. Probability curves are introduced, which inform the operator about the chance to work still in the fully aberration corrected state.

REPRINT OF: Aberration measurement in HRTEM: Implementation and diagnostic use of numerical procedures for the highly precise recognition of diffractogram patterns.

The precise characterisation of the instrumental imaging properties in the form of aberration parameters constitutes an almost universal necessity in quantitative HRTEM, and is underlying most hardware and software techniques established in this field. We focus in this paper on the numerical analysis of individual diffractograms as a first preparatory step for further publications on HRTEM aberration measurement. The extraction of the defocus and the 2-fold astigmatism from a diffractogram is a classical pattern recognition problem, which we believe to have solved in a near-optimum way concerning precision, speed, and robustness. The newly gained measurement precision allows us to resolve fluctuations of the defocus and the 2-fold astigmatism and to assess thereby the optical stability of electron microscopes. Quantitative stability criteria are elaborated, which may serve as helpful guidelines for daily work as well as for microscope acceptance tests.

Trocar site herniation of the small bowel after laparoscopic bilateral adnexectomy despite fascial closure: a case report.

In this paper we report a case of an incarcerated hernia occurring through the peritoneal and muscular defect caused by a previous trocar insertion. The patient developed the hernia eight days after bilateral laparoscopic adnexectomy and presented small bowel obstruction signs. This hernia occurred despite correct closure of the internal oblique fascia. The patient was re-operated and exploratory laparoscopy confirmed the diagnosis. The hernia was reduced via a small extension of the previous incision, and the defect was repaired by separated stitches. This case shows that a trocar site hernia can appear despite correct closure of the fascia, which is poorly described except for obese patients. It suggests the need for careful closure of the abdominal wall including the peritoneum after a laparoscopic procedure. Trocar site hernia has to be considered in cases of post laparoscopic small bowel obstruction. We reviewed the literature and found no randomized control study concerning this problem: only reviews, retrospective studies, case reports and technical notes. These papers are discussed and compared with our case.

Aberration measurement in HRTEM: implementation and diagnostic use of numerical procedures for the highly precise recognition of diffractogram patterns.

The precise characterisation of the instrumental imaging properties in the form of aberration parameters constitutes an almost universal necessity in quantitative HRTEM, and is underlying most hardware and software techniques established in this field. We focus in this paper on the numerical analysis of individual diffractograms as a first preparatory step for further publications on HRTEM aberration measurement. The extraction of the defocus and the 2-fold astigmatism from a diffractogram is a classical pattern recognition problem, which we believe to have solved in a near-optimum way concerning precision, speed, and robustness. The newly gained measurement precision allows us to resolve fluctuations of the defocus and the 2-fold astigmatism and to assess thereby the optical stability of electron microscopes. Quantitative stability criteria are elaborated, which may serve as helpful guidelines for daily work as well as for microscope acceptance tests.

[Laparoscopic adrenalectomy. Five-year experience]. / Suprarrenalectomía laparoscópica. Experiencia de 5 años.

OBJECTIVE: Adrenal conditions requiring surgery are uncommon and are usually seen in several surgical departments. Our experience in laparoscopic management of adrenal pathology after almost five years of use of laparoscopy for retroperitoneal conditions at our center is reported. MATERIALS AND METHODS: A total of 37 laparoscopic adrenalectomies were performed over 53 months for benign and malignant conditions. The transperitoneal approach was used in most cases (97%) because of the greater surgeon experience with this route. Pregnancy and suspected periadrenal infiltration were considered as absolute contraindications. RESULTS: Mean operating time was 90 minutes, mean intraoperative bleeding 80 ml, and mean hospital stay was 2 days. The main complication was one death. A malignancy was found in 4 patients (10%), while all other patients (90%) had a benign condition, including 8 pheochromocytomas. CONCLUSIONS: Laparoscopy is considered to be the gold standard for benign adrenal conditions. When the malignant mass is a single metastasis from a primary tumor, the laparoscopic approach appears to be reliable. When the malignant lesion is a primary adrenal tumor, laparoscopic management is more controversial, although the results reported by experienced surgeons in their series appear to be adequate.

[Laparoscopic nephron-sparing surgery. 5 years' experience]. / Cirugía conservadora de parénquima renal laparoscópica. Cinco años de experiencia.

INTRODUCTION: Laparoscopic nephron-sparing surgery is among the most complex urological procedures currently performed. Open surgery continues to be the gold standard of care, but the laparoscopic approach is gaining ground slowly but surely. Our 5 years' experience is reported. MATERIALS AND METHODS: From September 2004 to March 2009, 38 laparoscopic nephron-sparing procedures were performed at our hospital. A transperitoneal laparoscopic approach was used in all cases, with en bloc clamping of renal hilum in most patients. RESULTS: Mean operating time was 141 min, mean intraoperative bleeding 130 mL, mean warm ischemia time 24 min, and mean hospital stay 3.3 days. Bleeding was the most common complication (requiring transfusion in 13.5% of patients). Positive surgical margins were found in 5.4% of patients. CONCLUSIONS: Adequate selection of the patient (tumor size, location) and the procedure to be used, surgeon experience, and surgical skills are essential for achieving good oncological results and for minimizing the complications of this demanding procedure.