Emission Ghost Imaging: reconstruction with data augmentation.

Ghost Imaging enables 2D reconstruction of an object even though particles transmitted or emitted by the object of interest are detected with a single pixel detector without spatial resolution. This is possible because for the particular implementation of ghost imaging presented here, the incident beam is spatially modulated with a non-configurable attenuating mask whose orientation is varied (e.g. via transverse displacement or rotation) in the course of the ghost imaging experiment. Each orientation yields a distinct spatial pattern in the attenuated beam. In many cases, ghost imaging reconstructions can be dramatically improved by factoring the measurement matrix which consists of measured attenuated incident radiation for each of many orientations of the mask at each pixel to be reconstructed as the product of an orthonormal matrix Qand an upper triangular matrix R provided that the number of orientations of the mask (N) is greater than or equal to the number of pixels (P) reconstructed. For the N

Adapting the Stress First Aid Model for Frontline Healthcare Workers during COVID-19.

The coronavirus pandemic has generated and continues to create unprecedented demands on our healthcare systems. Healthcare workers (HCWs) face physical and psychological stresses caring for critically ill patients, including experiencing anxiety, depression, and posttraumatic stress symptoms. Nurses and nursing staff disproportionately experienced COVID-19-related psychological distress due to their vital role in infection mitigation and direct patient care. Therefore, there is a critical need to understand the short- and long-term impact of COVID-19 stress exposures on nursing staff wellbeing and to assess the impact of wellbeing programs aimed at supporting HCWs. To that end, the current study aims to evaluate an evidence-informed peer support stress reduction model, Stress First Aid (SFA), implemented across units within a psychiatric hospital in the New York City area during the pandemic. To examine the effectiveness of SFA, we measured stress, burnout, coping self-efficacy, resilience, and workplace support through self-report surveys completed by nurses and nursing staff over twelve months. The implementation of SFA across units has the potential to provide the workplace-level and individual-level skills necessary to reduce stress and promote resilience, which can be utilized and applied during waves of respiratory illness acuity or any other healthcare-related stressors among this population.

Prompt gamma ray activation analysis for determining chemical composition of 3D printing and casting materials used in biomedical applications.

Three-dimensional printing and casting materials were analyzed by prompt gamma-ray activation analysis (PGAA) to determine their suitability as human tissue surrogates for the fabrication of phantoms for medical imaging and radiation dosimetry applications. Measured elemental compositions and densities of five surrogate materials simulating soft tissue and bone were used to determine radiological properties (x-ray mass attenuation coefficient and electron stopping power). When compared with radiological properties of International Commission on Radiation Units and Measurements (ICRU) materials, it was determined that urethane rubber and PLA plastic yielded the best match for soft tissue, while silicone rubber and urethane resin best simulated the properties of bone.

Abdominal wall reconstruction for extensive necrosis following abdominoplasty in a patient with subcostal scars - case report.

Abdominal wall defects encompass a broad spectrum of musculo-fasciocutaneous anomalies. We present case of a 42-year-old woman with a history of multimorbidity and bilateral subcostal scars. The patient underwent incisional ventral hernia repair and abdominoplasty performed by a general surgeon at another institution. However, she developed extensive necrosis of the cutaneous-fatty panniculus between the bilateral subcostal incisions and the abdominoplasty incision. The patient presented with a medial area of 50 × 60 cm with loss of soft tissue vitality and necrotic plaques. Tangential escharotomies were performed to remove devitalized tissue, and management of the open wound included hydrocolloid and alginate dressings. Finally, a defect of 45 × 40 cm was achieved. Three tissue expanders were used to reconstruct the abdominal wall, allowing sufficient adjacent autologous tissue to be harvested for definitive correction of the abdominal defect. An acceptable aesthetic result was observed 5 years after surgery. This report highlights the importance of adequate evaluation of the previously scarred abdominal wall prior to abdominoplasty.

Physician challenges and supports during the first wave of the COVID-19 pandemic: A mixed methods study.

Introduction: During the COVID-19 pandemic, physicians encountered significant COVID-19-related negative experiences and psychological distress in both their personal and professional lives. To understand the factors that negatively impact physician well-being, a number of studies have pointed to multiple work system factors such as excessive workload and workflow interruptions. In addition, studies have shown that positive interpersonal relationships that provide social support may also serve as a buffering role against psychological distress. The aim of our study explores the challenges and sources of support for physicians relative to mental health symptoms. Methods: In this study, We used a cross-sectional study design with a convergent parallel mixed method approach combining both qualitative and quantitative data collected in parallel from a self-report questionnaire immediately following the first wave of COVID-19. The aim of our study explores the challenges and sources of support for physicians relative to mental health symptoms. Results: Of the 457 physicians in the study, the most frequently potential negative occupational experiences were, "Being at risk of contracting COVID-19 from patients/co-workers" (90.5%) and "Contact with distressed family members who cannot be with a loved one" (69.5%). We identified five common themes for main sources of social support (e.g. emotional support from family/friends) and six themes for challenges (e.g., work-related demands exacerbated by the pandemic). Discussion: Our study highlights COVID-19 and other pandemic-related challenges that negatively impacted the mental health of physicians. Interventions that provide targeted organizational supports (e.g. sufficient PPE and child support), as well as specific sources of support (e.g. family and emotional), can attenuate those challenges and stressors experienced during a pandemic.

Calorimetry in Computed Tomography Beams.

A portable calorimeter for direct realization of absorbed dose in medical computed tomography (CT) procedures was constructed and tested in a positron emission tomography (PET) CT scanner. The calorimeter consists of two small thermistors embedded in a polystyrene (PS) cylindrical "core" (1.5 cm diameter) that can be inserted into a cylindrical high-density polyethylene (HDPE) phantom (30 cm diameter). The cylindrical design of core and phantom allows coaxial alignment of the system with the scanner rotation axis, which is necessary to minimize variations in dose that would otherwise occur as the X-ray source is rotated during scanning operations. The core can be replaced by a cylindrical ionization chamber for comparing dose measurement results. Measurements using the core and a calibrated thimble ionization chamber were carried out in a beam of 6 MV X-rays from a clinical accelerator and in 120 kV X-rays from a CT scanner. Doses obtained from the calorimeter and chamber in the 6 MV beam exhibited good agreement over a range of dose rates from 0.8 Gy/min to 4 Gy/min, with negligible excess heat. For the CT beam, as anticipated for these X-ray energies, the calorimeter response was complicated by excess heat from device components. Analyses done in the frequency domain and time domain indicated that excess heat increased calorimetric temperature rise by a factor of about 15. The calorimeter's response was dominated by dose to the thermistor, which contains high-atomic-number elements. Therefore, for future construction of calorimeters for CT beams, lower-atomic-number temperature sensors will be needed. These results serve as a guide for future alternative design of calorimeters toward a calorimetry absorbed dose standard for diagnostic CT.

RED BREAST SYNDROME (RBS) ASSOCIATED TO THE USE OF POLYGLYCOLIC MESH IN BREAST RECONSTRUCTION: A CASE REPORT.

Some patients undergoing breast reconstruction with acellular dermal matrices (ADMs) develop postoperative erythema overlying their ADM grafts named red breast syndrome (RBS). To the best of our knowledge this entity has never been related to the use of a synthetic mesh. We present a case of a 61-year-old patient who underwent bilateral nipple-sparing prophylactic mastectomy because of BRCA-1 gene mutation. The patient was reconstructed with a direct-to-implant approach, and the implants were covered with a polyglycolic acid mesh. Twenty days after the reconstruction, she presented with a blanching erythema of both reconstructed breasts without signs of infection on the area covered by the mesh. The patient denied symptoms like fever or tenderness and presented with no clinical signs of infection. Her laboratory tests were within normal range. We decided to watch and wait. The patient continued strict controls in the outpatient setting. Gradually, the erythema begun to disappear and it resolved spontaneously. RBS has only been described with the use of ADMs, but since in this case the mesh was made of polyglycolic acid, we suggest RBS should be considered either with the use of biological or synthetic meshes. The importance of its differential diagnosis resides in distinguishing it from an infection.

[Unilateral approach for over the top bilateral lumbar decompression]. / Bilaterale mikrochirurgische Dekompression der lumbalen Spinalkanalstenose über einen unilateralen Zugang.

OBJECTIVE: The main goal is bilateral microsurgical decompression of the cauda equina using a unilateral over the top approach. The challenge is to achieve decompression with minimal iatrogenic trauma to anatomical structures in the approach region and in the target area. INDICATIONS: Degenerative spinal disorders including lumbar central stenosis, lumbar lateral recess spinal stenosis, and foraminal narrowing. This technique is performed in patients presenting primarily with neurogenic claudication, leg or buttock symptoms, heaviness in the legs with or without radicular symptoms, with or without neurological deficits, and comparable MRI findings. There are no limitations regarding number of affected segments or the extent of narrowing. CONTRAINDICATIONS: All available conservative treatment modalities not exhausted. Lack of serious neurological deficit. SURGICAL TECHNIQUE: Minimally invasive, muscle-sparing and facet-joint-sparing bilateral enlargement of the lumbar spinal canal through a unilateral microsurgical cross-over approach. POSTOPERATIVE MANAGEMENT: Patients are mobilized early 4-6 h postoperatively. Light sports activities (e.g., ergometer cycling, swimming) are allowed after 2 weeks. The same is true for the return to normal daily or work activities except for heavy physical work (usually 4 weeks out of work). Soft lumbar brace for 4 weeks (optional). RESULTS: The clinical outcomes are good to excellent. Meta-analyses and large case series report success rates for microsurgical decompression procedures of 73.5-95%. The reoperation rates are low (0.5-10%).

A History of Endoscopic Lumbar Spine Surgery: What Have We Learnt?

The new development and finally the general acceptance of surgical techniques among the worldwide surgical community sometimes create fascinating stories. This is also true for the history of endoscopic lumbar spine surgery. In the last 100 years there was a "natural" evolution of surgical techniques with continuous improvement and "refinement" of lumbar decompression techniques towards less invasive operations with the final "endpoint" of microsurgery. However the application of percutaneous, image-guided, and endoscopic technologies has revolutionized minimally invasive surgery. This article describes the history of endoscopic lumbar spine surgery and its major milestones and protagonists which have helped to make endoscopic lumbar spine surgery "disruptive" minimally invasive surgical technology which has changed the world of lumbar decompression surgery. "The past is the mother of the future"Henri Cartier Bresson, French Photographer, 1908-2004.

SQUID-based detection of ultra-low-field multinuclear NMR of substances hyperpolarized using signal amplification by reversible exchange.

Ultra-low-field (ULF) nuclear magnetic resonance (NMR) is a promising spectroscopy method allowing for, e.g., the simultaneous detection of multiple nuclei. To overcome the low signal-to-noise ratio that usually hampers a wider application, we present here an alternative approach to ULF NMR, which makes use of the hyperpolarizing technique signal amplification by reversible exchange (SABRE). In contrast to standard parahydrogen hyperpolarization, SABRE can continuously hyperpolarize 1 H as well as other MR-active nuclei. For simultaneous measurements of 1 H and 19 F under SABRE conditions a superconducting quantum interference device (SQUID)-based NMR detection unit was adapted. We successfully hyperpolarized fluorinated pyridine derivatives with an up to 2000-fold signal enhancement in 19 F. The detected signals may be explained by two alternative reaction mechanisms. SABRE combined with simultaneous SQUID-based broadband multinuclear detection may enable the quantitative analysis of multinuclear processes.

Clinical and radiological outcome at 10 years of follow-up after total cervical disc replacement.

PURPOSE: Previous studies have demonstrated that total cervical disc replacement (cTDR) represents a viable treatment alternative to the 'gold standard' anterior cervical discectomy and fusion for the treatment of well-defined cervical pathologies at short- and mid-term follow-up (FU). However, the implementation and acceptance of a non-fusion philosophy is closely associated with its avoidance of adjacent segment degeneration. Proof of the functional sustainability and clinical improvement of symptoms at long-term FU is still pending. The aim of this ongoing prospective study was to investigate the clinical and radiological results of cTDR at long-term FU. METHODS: 50 patients were treated surgically within a non-randomised prospective study framework with cTDR (ProDisc C™, Synthes, Paoli, PA, USA). Patients were examined preoperatively followed by routine clinical and radiological examinations at 1, 5 and 10 years after surgery, respectively. In addition to the clinical scores, conventional X-ray images of the cervical spine were taken in anteroposterior and lateral view as well as flexion/extension images. Clinical outcome scores included parameters such as the Neck Disability Index (NDI), Visual Analogue Scale (VAS), arm and neck pain self-assessment questionnaires as well as subjective patient satisfaction rates. The radiological outcome variables included the range of motion (ROM) of the implanted prosthesis between maximum flexion and extension images, the occurrence of heterotopic ossifications and radiographic signs of adjacent segment degenerative changes. The reoperation rate following cTDR was recorded as a secondary outcome variable. RESULTS: A significant and maintained clinical improvement of all clinical outcome scores was observed after a mean FU of 10.2 years (VASarm 6.3-2.1; VASneck 6.4-1.9; NDI 21-6; p < 0.05). An increase in the incidence and the extent of heterotopic ossifications was noted during the post-operative course with a significant influence on the function of the prosthesis, which, however, did not reveal any detrimental effect on the patients' clinical symptomatology. Prosthesis mobility declined from 9.0° preoperatively and 9.1° at 1 year FU to 7.7° and 7.6° at the five- and ten-year FU examinations, respectively. Radiological signs of adjacent segment degeneration were detected in 13/38 (35.7%), however, in only 3/38 (7.9%) patients this radiological changes were associated with clinical symptoms requiring conservative treatment. Intraoperative technical failure in two cases required interbody fusion with a cage (2/50). One patient (1/48, 2.1%) treated this motion device had revision surgery at the index level. CONCLUSION: Cervical total disc replacement with ProDisc C demonstrated a significant and maintained improvement of all clinical outcome parameters at a follow-up of ≥10 years. The present long-term data reveal that with an exceptionally low implant-related reoperation rate and low symptomatic adjacent segment degeneration rate, cTDR may be regarded as a safe and viable treatment option.

Development and Validation of the iDI: A Short Self-Rating Disability Instrument for Low Back Pain Disorders.

STUDY DESIGN: Cross-sectional and longitudinal validation study. OBJECTIVE: Development and validation of a short, reliable, and valid questionnaire for the assessment of low back pain-related disability. METHODS: The iDI was created in a stepwise procedure: (1) its development was based on the literature and theoretical consideration; (2) outcome data were collected and evaluated in a pilot study; (3) final validations were performed based on an international multicenter spine surgery outcome study including 514 patients; (4) the iDI was programmed for a tablet computer (iPad) and tested for its clinical practicability. RESULTS: The final version of the iDI comprises of 8 simple questions related to different aspects of disability with a 5-point Likert-type answer scale. The iDI compared very well to the Oswestry Disability Index in terms of reliability and validity. The iDI was demonstrated to be suitable for data assessment on a tablet computer (iPad). CONCLUSIONS: The iDI is a short, valid, and practicable tool that facilitates routine quality assessment in terms of low back pain-related disability.

Rapid determination of the various native forms of vitamin B6 and B2 in cow's milk using ultra-high performance liquid chromatography.

As the formation of pyridoxal phosphate, the active cofactor of vitamin B6, is dependent on riboflavin 5-phosphate, we propose a fast and simple ultra-high performance liquid chromatography method for the simultaneous determination of the native B6 vitamers pyridoxal, pyridoxine, pyridoxamine, their mono phosphorus esters and 4-pyridoxic acid as well as vitamin B2 as riboflavin and its phosphorus ester riboflavin 5-phosphate in milk. Separation was achieved under 6.0min by reversed-phase and pH gradient elution. Sample preparation was optimized regarding various acids and pH levels. Changes in those parameters led to significant deviations of sample matrix breakdown efficiency. The optimized method was then validated regarding specificity, accuracy, precision, linearity, range, detection and quantification limits. As the method performed satisfactory, is was used to study commercial liquid cow's milk (n=31), regarding effects of the employed preservation technique (pasteurization, extended shelf-life, ultra-high temperature) on the composition and content of B6 and B2 vitamers. In cow's milk, vitamin B6 mostly consists of pyridoxal and its phosphate ester, with pyridoxal phosphate being the bulk component. The catabolite of the vitamin B6 metabolism, 4-pyridoxic acid was present in significant amounts in all studied samples, with up to 2.69µmolL-1. Vitamin B2 was present as riboflavin and its phosphate ester up to 12.86µmolL-1.

Comparison of One-Dimensional and Volumetric Computed Tomography Measurements of Injected-Water Phantoms.

The goal of this study was to compare volumetric analysis in computed tomography (CT) with the length measurement prescribed by the Response Evaluation Criteria in Solid Tumors (RECIST) for a system with known mass and unknown shape. We injected 2 mL to 4 mL of water into vials of sodium polyacrylate and into disposable diapers. Volume measurements of the sodium polyacrylate powder were able to predict both mass and proportional changes in mass within a 95 % prediction interval of width 12 % and 16 %, respectively. The corresponding figures for RECIST were 102 % and 82 %.

[Surgical treatment of lumbar disc herniation]. / Operative Therapie des lumbalen Bandscheibenvorfalls.

OBJECTIVE: Herniated disc tissue removal to decompress the spinal nerve/cauda equina. Minimization of iatrogenic trauma and associated injuries. INDICATIONS: Conservative treatment did not sufficiently improve clinical symptoms. This is true for progressive or persisting neurological deficits, as well as for persisting pain which alters the quality of the patient`s life. Results of surgery are strongly dependent on the preoperative duration of symptoms. Paramount is the "timing" of surgery: poorer surgical results associated with increasing preoperative duration of symptoms. CONTRAINDICATIONS: Conservative treatment modalities have not been exhausted. SURGICAL TECHNIQUES: There are 2 technologies (endoscopic/microsurgical) and 5 different approach strategies (endoscopic: interlaminar, transforaminal; microsurgical: interlaminar, translaminar, extraforaminal), whereby the choice is determined by morphology and location of the herniated disc. All techniques are minimally invasive and lead to comparable clinical results. POSTOPERATIVE MANAGEMENT: For all techniques, patients are mobilized early. Light sports activities allowed after 2 weeks and return to work after about 4 weeks. RESULTS: Good clinical outcomes in meta-analyses/large case series are between 80-95 %.

Role of cervical cerclage and prolonged antibiotic therapy with azithromycin in patients with previous perinatal loss amnionitis.

In the group of 35 patients with cerclage, intermediate fetal mortality was reduced from 37.1% to 0 (p < 0.001); late fetal mortality rate from 8.5% to 2.8% (p = 0.606); prematurity from 65.7% to 5.7% (p < 0.001); newborn underweight from 11.4% to 5.7% (p = 0.671); newborns with very low weight from 34.2% to 0 (p < 0.001) and the abortion rate from 8.5% to 0 ( p < 0.001). In the group of 19 patients without buckling, intermediate fetal mortality was reduced from 26.3% to 10.5% (p = 402); late fetal mortality from 63.1% to 0 (p < 0.001); prematurity 78.9% to 31.5% (p < 0.009); the newborn of low weight from 31.5% to 10.5% (p = 0.234); newborns with very low weight from 68.4% to 15.7% (p < 0.003) and the abortion rate from 36.8 to 0 (p < 0.001). In conclusion, we believe the results of this study demonstrate the effectiveness of therapeutic and prophylactic cervical cerclage associated with prolonged antibiotic therapy.

"Slalom": Microsurgical Cross-Over Decompression for Multilevel Degenerative Lumbar Stenosis.

Objective. Selective, bilateral multisegmental microsurgical decompression of lumbar spinal canal stenosis through separate, alternating cross-over approaches. Indications. Two-segmental and multisegmental degenerative central and lateral lumbar spinal stenosis. Contraindications. None. Surgical Technique. Minimally invasive, muscle, and facet joint-sparing bilateral decompression of the lumbar spinal canal through 2 or more alternating microsurgical cross-over approaches from one side. Results. From December 2010 until December 2015 we operated on 202 patients with 2 or multisegmental stenosis (115 f; 87 m; average age 69.3 yrs, range 51-91 yrs). All patients were suffering from symptoms typical of a degenerative lumbar spinal stenosis. All patients complained about back pain; however the leg symptoms were dominant in all cases. Per decompressed segment, the average OR time was 36 min and the blood loss 45.7 cc. Patients were mobilized 6 hrs postop and hospitalization averaged 5.9 days. A total of 116/202 patients did not need submuscular drainage. 27/202 patients suffered from a complication (13.4%). Dural tears occurred in 3.5%, an epidural hematoma in 5.5%, a deep wound infection in 1.98%, and a temporary radiculopathy postop in 1.5%. Postop follow-up ranged from 12 to 24 months. There was a significant improvement of EQ 5 D, Oswestry Disability Index (ODI), VAS for Back and Leg Pain, and preoperative standing times and walking distances.