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Objective: Interactive three-dimensional virtual models of pulmonary structures (3D-CT) may improve the safety and accuracy of robotic-assisted thoracic surgery (RATS). The aim of this study was to evaluate the impact of 3D-CT models as an imaging adjunct on surgical confidence and anatomical assessment for lobectomy planning. Methods: We retrospectively analyzed the response of 10 specialist thoracic surgeons who each reviewed 10 pre-operative images of patients undergoing robotic-assisted lobectomy lung cancer cases from June to November 2018 in our institute, resulting in 100 data points. The number of arteries, veins, and bronchi entering the resected lobes were determined from the operation video recording by the operating surgeon. 3D-CT models were generated for each case and made available for online visualization and manipulation. Thoracic surgeons were invited to participate in the survey which consisted of evaluation of CT (control) and 3D-CT (intervention) models. A questionnaire regarding anatomical structures, surgical approach, and confidence was administered. Results: Ten participants were recruited. 3D-CT models led to a significant (p < 0.003) increase in the surgeons' ability to correctly identifying pulmonary arteries entering the resection lobes in 35% (CT) and 57% (3D-CT) of cases. A significant (p < 1e-13) improvement in anatomy assessment and surgical plan confidence was observed for the 3D-CT arm, with median Likert scale scores of "2-Slightly easy" (CT) and "4-Very easy" (3D-CT). Conclusion: The use of 3D-CT models for thoracic surgery planning increases the surgeon confidence in recognizing anatomical structures, largely by enhanced appreciation of anatomical variations in the segmental pulmonary arterial system. Further studies are needed to investigate if 3D-CT models can be used in providing precise information about segmental artery distribution and therefore surgical planning of sub-lobar resections.
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Gammaherpesviruses are ubiquitous pathogens that establish lifelong infections in the majority of adults worldwide. Chronic gammaherpesvirus infection has been implicated in both lymphomagenesis and, somewhat controversially, autoimmune disease development. Pathogenesis is largely associated with the unique ability of gammaherpesviruses to usurp B cell differentiation, specifically, the germinal center response, to establish long-term latency in memory B cells. The host tyrosine phosphatase SHP1 is known as a brake on immune cell activation and is downregulated in several gammaherpesvirus-driven malignancies. However, here we demonstrate that B cell- but not T cell-intrinsic SHP1 expression supports the gammaherpesvirus-driven germinal center response and the establishment of viral latency. Furthermore, B cell-intrinsic SHP1 deficiency cooperated with gammaherpesvirus infection to increase the levels of double-stranded DNA-reactive antibodies at the peak of viral latency. Thus, in spite of decreased SHP1 levels in gammaherpesvirus-driven B cell lymphomas, B cell-intrinsic SHP1 expression plays a proviral role during the establishment of chronic infection, suggesting that the gammaherpesvirus-SHP1 interaction is more nuanced and is modified by the stage of infection and pathogenesis.IMPORTANCE Gammaherpesviruses establish lifelong infection in a majority of adults worldwide and are associated with a number of malignancies, including B cell lymphomas. These viruses infect naive B cells and manipulate B cell differentiation to achieve a lifelong infection of memory B cells. The germinal center stage of B cell differentiation is important as both an amplifier of the viral latent reservoir and the target of malignant transformation. In this study, we demonstrate that expression of tyrosine phosphatase SHP1, a negative regulator that normally limits the activation and proliferation of hematopoietic cells, enhances the gammaherpesvirus-driven germinal center response and the establishment of chronic infection. The results of this study uncover an intriguing beneficial interaction between gammaherpesviruses that are presumed to profit from B cell activation and a cellular phosphatase that is traditionally perceived to be a negative regulator of the same processes.
Subject(s)
B-Lymphocytes/immunology , Germinal Center/immunology , Herpesviridae Infections/genetics , Host-Pathogen Interactions/genetics , Protein Tyrosine Phosphatase, Non-Receptor Type 6/genetics , Rhadinovirus/genetics , Tumor Virus Infections/genetics , Animals , Antibodies, Antinuclear/biosynthesis , B-Lymphocytes/virology , Chronic Disease , DNA/genetics , DNA/immunology , Female , Germinal Center/virology , Herpesviridae Infections/immunology , Herpesviridae Infections/pathology , Herpesviridae Infections/virology , Host-Pathogen Interactions/immunology , Humans , Immunologic Memory , Lymphocyte Activation , Male , Mice , Mice, Transgenic , Primary Cell Culture , Protein Tyrosine Phosphatase, Non-Receptor Type 6/deficiency , Protein Tyrosine Phosphatase, Non-Receptor Type 6/immunology , Rhadinovirus/immunology , Rhadinovirus/pathogenicity , T-Lymphocytes/immunology , T-Lymphocytes/virology , Tumor Virus Infections/immunology , Tumor Virus Infections/pathology , Tumor Virus Infections/virology , Virus Latency/genetics , Virus Latency/immunologyABSTRACT
BACKGROUND: Vascular damage in polytrauma patients is associated with high mortality and morbidity. Therefore, specific clinical implications of vascular damage with fractures in major trauma patients are reassessed. METHODS: This comprehensive nine-year retrospective single center cohort study analyzed demography, laboratory, treatment and outcome data from 3689 patients, 64 patients with fracture-associated vascular injuries were identified and were compared to a control group. RESULTS: Vascular damage occurred in 7% of patients with upper and lower limb and pelvic fractures admitted to the trauma room. Overall survival was 80% in pelvic fracture and 97% in extremity fracture patients and comparable to non-vascular trauma patients. Additional arterial damage required substantial fluid administration and was visible as significantly anemia and disturbed coagulation tests upon admission. Open procedures were done in over 80% of peripheral extremity vascular damage. Endovascular procedures were predominant (87%) in pelvic injury. CONCLUSION: Vascular damage is associated with high mortality rates especially in combination with pelvic fractures. Initial anemia, disturbed coagulation tests and the need for extensive pre-clinical fluid substitution were observed in the cohort with vascular damage. Therefore, fast diagnosis and early interventional and surgical procedures are necessary to optimize patient-specific outcome.
Subject(s)
Fractures, Bone/diagnostic imaging , Hemorrhage/diagnostic imaging , Pelvic Bones/blood supply , Pelvic Bones/diagnostic imaging , Vascular System Injuries/diagnostic imaging , Adult , Aged , Cohort Studies , Female , Fractures, Bone/complications , Fractures, Bone/surgery , Hemorrhage/etiology , Hemorrhage/surgery , Humans , Lower Extremity/diagnostic imaging , Lower Extremity/injuries , Lower Extremity/surgery , Male , Middle Aged , Pelvic Bones/surgery , Retrospective Studies , Upper Extremity/diagnostic imaging , Upper Extremity/injuries , Upper Extremity/surgery , Vascular System Injuries/etiology , Vascular System Injuries/surgeryABSTRACT
Horseshoe kidney is a rare renal fusion anomaly, and because of limited mobilization of the kidney and its multiple arterial blood supplies, minimally invasive surgery for renal tumors can be challenging. We describe a case of a right-side oncocytoma in a horseshoe kidney managed robotically and review the literature of robotic-assisted laparoscopic surgical resection of kidney tumors in renal fusion anomalies. Robotic-assisted laparoscopic partial nephrectomy in a horseshoe kidney is feasible. Fusion-related limited mobility during the procedure, as well as an extremely variable blood supply, require meticulous planning. Multi-phase computed tomography and interactive 3D anatomical models are helpful tools to prepare for surgery.
Subject(s)
Fused Kidney/surgery , Imaging, Three-Dimensional , Kidney Neoplasms/surgery , Laparoscopy/methods , Nephrectomy/methods , Robotic Surgical Procedures/methods , Blood Loss, Surgical , Carcinoma, Renal Cell/diagnostic imaging , Carcinoma, Renal Cell/pathology , Carcinoma, Renal Cell/surgery , Female , Follow-Up Studies , Fused Kidney/diagnostic imaging , Fused Kidney/pathology , Humans , Kidney Neoplasms/diagnostic imaging , Kidney Neoplasms/pathology , Middle Aged , Minimally Invasive Surgical Procedures/methods , Operative Time , Preoperative Care/methods , Tomography, X-Ray Computed/methods , Treatment OutcomeABSTRACT
In a recent paper [U. Lorenz and P. Saalfrank, Chem. Phys. 482, 69 (2017)], we proposed a robust scheme to set up a system-bath model Hamiltonian, describing the coupling of adsorbate vibrations (system) to surface phonons (bath), from first principles. The method is based on an embedded cluster approach, using orthogonal coordinates for system and bath modes, and an anharmonic phononic expansion of the system-bath interaction up to second order. In this contribution, we use this model Hamiltonian to calculate vibrational relaxation rates of H-Si and D-Si bending modes, coupled to a fully H(D)-covered Si(100)-(2×1) surface, at zero temperature. The D-Si bending mode has an anharmonic frequency lying inside the bath frequency spectrum, whereas the H-Si bending mode frequency is outside the bath Debye band. Therefore, in the present calculations, we only take into account one-phonon system-bath couplings for the D-Si system and both one- and two-phonon interaction terms in the case of H-Si. The computation of vibrational lifetimes is performed with two different approaches, namely, Fermi's golden rule, and a generalized Bixon-Jortner model built in a restricted vibrational space of the adsorbate-surface zeroth-order Hamiltonian. For D-Si, the Bixon-Jortner Hamiltonian can be solved by exact diagonalization, serving as a benchmark, whereas for H-Si, an iterative scheme based on the recursive residue generation method is applied, with excellent convergence properties. We found that the lifetimes obtained with perturbation theory, albeit having almost the same order of magnitude-a few hundred fs for D-Si and a couple of ps for H-Si-, are strongly dependent on the discretized numerical representation of the bath spectral density. On the other hand, the Bixon-Jortner model is free of such numerical deficiencies, therefore providing better estimates of vibrational relaxation rates, at a very low computational cost. The results obtained with this model clearly show a net exponential decay of the time-dependent survival probability for the H-Si initial vibrational state, allowing an easy extraction of the bending mode "lifetime." This is in contrast with the D-Si system, whose survival probability exhibits a non-monotonic decay, making it difficult to define such a lifetime. This different behavior of the vibrational decay is rationalized in terms of the power spectrum of the adsorbate-surface system. In the case of D-Si, it consists of several, non-uniformly distributed peaks around the bending mode frequency, whereas the H-Si spectrum exhibits a single Lorentzian lineshape, whose width corresponds to the calculated lifetime. The present work gives some insight into mechanisms of vibration-phonon coupling at surfaces. It also serves as a benchmark for multidimensional system-bath quantum dynamics, for comparison with approximate schemes such as reduced, open-system density matrix theory (where the bath is traced out and a Liouville-von Neumann equation is solved) or approximate wavefunction methods to solve the combined system-bath Schrödinger equation.
ABSTRACT
This corrects the article DOI: 10.1103/PhysRevLett.111.034802.
ABSTRACT
We present results of a coherent x-ray diffractive imaging experiment performed on a single colloidal crystal grain. The full three-dimensional (3D) reciprocal space map measured by an azimuthal rotational scan contained several orders of Bragg reflections together with the coherent interference signal between them. Applying the iterative phase retrieval approach, the 3D structure of the crystal grain was reconstructed and positions of individual colloidal particles were resolved. As a result, an exact stacking sequence of hexagonal close-packed layers including planar and linear defects were identified.
ABSTRACT
X-ray free-electron lasers (XFELs) may allow us to employ the single-particle imaging (SPI) method to determine the structure of macromolecules that do not form stable crystals. Ultrashort pulses of 10 fs and less allow us to outrun complete disintegration by Coulomb explosion and minimize radiation damage due to nuclear motion, but electronic damage is still present. The major contribution to the electronic damage comes from the plasma generated in the sample that is strongly dependent on the amount of Auger ionization. Since the Auger process has a characteristic time scale on the order of femtoseconds, one may expect that its contribution will be significantly reduced for attosecond pulses. Here we study the effect of electronic damage on the SPI at pulse durations from 0.1 to 10 fs and in a large range of XFEL fluences to determine optimal conditions for imaging of biological samples. We analyzed the contribution of different electronic excitation processes and found that at fluences higher than 10(13)-10(15) photons/µm(2) (depending on the photon energy and pulse duration) the diffracted signal saturates and does not increase further. A significant gain in the signal is obtained by reducing the pulse duration from 10 to 1 fs. Pulses below a duration of 1 fs do not give a significant gain in the scattering signal in comparison with 1-fs pulses. We also study the limits imposed on SPI by Compton scattering.
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We report on measurements of second-order intensity correlations at the high-brilliance storage ring PETRA III using a prototype of the newly developed adaptive gain integrating pixel detector. The detector records individual synchrotron radiation pulses with an x-ray photon energy of 14.4 keV and repetition rate of about 5 MHz. The second-order intensity correlation function is measured simultaneously at different spatial separations, which allows us to determine the transverse coherence length at these x-ray energies. The measured values are in a good agreement with theoretical simulations based on the Gaussian Schell model.
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We compare two methods for creating stochastic temperature wave functions that can be used for Multi-Configuration Time-Dependent Hartree (MCTDH) simulations. In the first method, the MCTDH coefficients are chosen randomly, while the other method uses a single Hartree product of random single-particle functions (SPFs). We find that using random SPFs dramatically improves convergence for a model system for surface sticking.
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The structural evolution of colloidal crystals made of polystyrene hard spheres has been studied in situ upon incremental heating of a crystal in a temperature range below and above the glass transition temperature of polystyrene. Thin films of colloidal crystals having different particle sizes were studied in transmission geometry using a high-resolution small-angle X-ray scattering setup at the P10 Coherence Beamline of the PETRA III synchrotron facility. The transformation of colloidal crystals to a melted state has been observed in a narrow temperature interval of less than 10â K.
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We present measurements of second- and higher-order intensity correlation functions (so-called Hanbury Brown-Twiss experiment) performed at the free-electron laser (FEL) FLASH in the non-linear regime of its operation. We demonstrate the high transverse coherence properties of the FEL beam with a degree of transverse coherence of about 80% and degeneracy parameter of the order 10(9) that makes it similar to laser sources. Intensity correlation measurements in spatial and frequency domain gave an estimate of the FEL average pulse duration of 50 fs. Our measurements of the higher-order correlation functions indicate that FEL radiation obeys Gaussian statistics, which is characteristic to chaotic sources.
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Arterial embolism with lower limb ischemia is a rare manifestation of paraneoplastic hypercoagulability in cancer patients. We report a unique case of fatal thromboembolism involving both circulations associated with a poorly differentiated neuroendocrine tumor of the lung with rapid progress despite high doses of unfractioned heparin and review the current literature on anticoagulative regimen in tumour patients.
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In single-particle coherent x-ray diffraction imaging experiments, performed at x-ray free-electron lasers (XFELs), samples are exposed to intense x-ray pulses to obtain single-shot diffraction patterns. The high intensity induces electronic dynamics on the femtosecond time scale in the system, which can reduce the contrast of the obtained diffraction patterns and adds an isotropic background. We quantify the degradation of the diffraction pattern from ultrafast electronic damage by performing simulations on a biological sample exposed to x-ray pulses with different parameters. We find that the contrast is substantially reduced and the background is considerably strong only if almost all electrons are removed from their parent atoms. This happens at fluences of at least one order of magnitude larger than provided at currently available XFEL sources.
Subject(s)
Biopolymers/chemistry , Biopolymers/radiation effects , Models, Biological , Models, Chemical , X-Rays , Computer Simulation , Radiation DosageABSTRACT
The energy partitioning in the UV photodissociation of N(2)O is investigated by means of quantum mechanical wave packet and classical trajectory calculations using recently calculated potential energy surfaces. Vibrational excitation of N(2) is weak at the onset of the absorption spectrum, but becomes stronger with increasing photon energy. Since the NNO equilibrium angles in the ground and the excited state differ by about 70°, the molecule experiences an extraordinarily large torque during fragmentation producing N(2) in very high rotational states. The vibrational and rotational distributions obtained from the quantum mechanical and the classical calculations agree remarkably well. The shape of the rotational distributions is semi-quantitatively explained by a two-dimensional version of the reflection principle. The calculated rotational distribution for excitation with λ = 204 nm and the translational energy distribution for 193 nm agree well with experimental results, except for the tails of the experimental distributions corresponding to excitation of the highest rotational states. Inclusion of nonadiabatic transitions from the excited to the ground electronic state at relatively large N(2)-O separations, studied by trajectory surface hopping, improves the agreement at high j.
Subject(s)
Nitrous Oxide/chemistry , Electrons , Photolysis , Quantum TheoryABSTRACT
OBJECTIVES: Biophotonic imaging was compared to standard enumeration method both for counting Staphylococcus aureus in biofilm and bacterial susceptibility tests of different graft materials. DESIGN: Prospective, randomized, controlled animal study. MATERIAL AND METHODS: Five types of vascular grafts were placed subcutaneously in 35 mice and challenged with bioluminescent S. aureus. The mice were divided into equal groups as follows: group A (polyester), group B (polytetrafluoroethylene), group C and D (two types of silver acetate-coated polyester) and group E (bovine pericardium). Controls were given only the bacteria. The bioluminescence signal of S. aureus, able to predict number of viable bacteria in biofilm without any manipulation, was measured at different time points. Five days postinfection, regular cultures of adherent bacteria on grafts were obtained. Comparative analyses between bioluminescence activity and culture enumeration were performed. RESULTS: The number of viable bacteria on silver-coated prostheses was the slightest, indicating superior bacterial resistance. The density of bacteria on polytetrafluoroethylene and polyester was comparable, with a non-significant advantage for polytetrafluoroethylene. Moreover, bioluminescence detected the number of viable S. aureus in biofilm more exactly compared to enumeration of bacteria. CONCLUSION: Bioluminescence imaging can be considered a useful tool to characterize susceptibility of any graft material to bacterial biofilm prior to implantation.
Subject(s)
Biofilms , Blood Vessel Prosthesis/microbiology , Luminescent Measurements/methods , Photons , Prosthesis-Related Infections/diagnosis , Staphylococcus aureus/physiology , Acetates , Animals , Bioprosthesis , Cattle , Colony Count, Microbial , Mice , Microbial Viability , Pericardium , Polyesters , Polytetrafluoroethylene , Prospective Studies , Random Allocation , Silver Compounds , Staphylococcus aureus/isolation & purificationABSTRACT
AIM: The IMAGE prosthesis was developed with the objective of proximal load induction to avoid stress shielding and proximal bone resorption. In this study patients were followed clinically and radiologically with a special emphasis on osteointegration of the shaft in the proximal and distal regions. In addition, the reconstruction of the bony geometry of the proximal humerus was investigated. METHOD: 95 consecutive patients (mean age: 61.1 years) with an IMAGE shaft were followed up prospectively over five years after primary hip arthroplasty. Radiologically, the osteointegration was appraised on the basis of the parameters cortical bone hypertrophy, radiolucent lines, shaft sintering and the position of the rotational centre. The clinical parameters assessed were the Harris hip score (HSS) and the WOMAC score. RESULTS: In Dorr C configuration no distal cortical bone hypertrophy was visible, in contrast to 19% in types A and B. By means of this criterion in 81% of the cases, a metaphyseal anchoring can be assumed. In 20% of the cases proximal and in 11.1% distal radiolucent lines were found. In only 3.3 % of the patients were the radiolucent lines due to unwanted distal osteointegration. In most cases the reasons were PE wear and metallosis. In 18.8% a distal anchoring was visible. Sintering (in total 18 prostheses) was greatest in Dorr C configuration and high-grade osteoporosis. The difference in offset reconstruction was 4.23 mm on average. In reconstruction of the rotational centre the variability was between 2.0 and 6.9 mm. 94.13 points were attained in the HHS and 10.13 points in the WOMAC score. Specific complications related to the implantation were not observed. CONCLUSIONS: Proximal stress transmission can be supported and the danger of stress shielding can be reduced by means of an appropriate design of a prosthetic stem. Distal corticoid hypertrophy was found in only 19% of the patients with the prosthesis model investigated as compared to 60% having prostheses with distal femoral anchoring. The medium-term clinical results are excellent, so that the shaft appears suitable for primary as well as secondary osteoarthritis of the hip joint.
Subject(s)
Femur/physiopathology , Hip Prosthesis , Osseointegration/physiology , Osteolysis/diagnostic imaging , Osteolysis/physiopathology , Postoperative Complications/diagnostic imaging , Postoperative Complications/physiopathology , Prosthesis Design , Titanium , Weight-Bearing/physiology , Adult , Aged , Aged, 80 and over , Alloys , Biomechanical Phenomena , Bone Remodeling/physiology , Equipment Failure Analysis , Female , Femur/diagnostic imaging , Humans , Hyperostosis/diagnostic imaging , Hyperostosis/physiopathology , Image Processing, Computer-Assisted , Male , Middle Aged , Prospective Studies , Tomography, X-Ray ComputedABSTRACT
BACKGROUND: The definition of generalized osteoarthritis in the literature is just as controversial as the discussion about correlations between GOA and Heberden's nodes (HN). Therefore, both questions were investigated in patients with proven heredity in a genealogical study of 931 family members. MATERIAL AND METHODS: In 106 patients with HN and 109 control subjects, 70 joints and spinal segments were investigated with respect to characteristic functional parameters. In addition, 44 joints and spinal segments were investigated radiologically. RESULTS: GOA affects both the small and large joints as well as the spine. This phenomenon is the more pronounced the more finger joints are affected by Heberden's and Bouchard's nodes. CONCLUSIONS: GOA affects the entire musculoskeletal system. The varying manifestation in individual joints and spinal segments is probably attributable to multifactorial local and systemic factors. In an earlier study, a genetic disposition with a maximum HA prevalence of 30% was identified in the study population. Since HA is considered a genetic marker for GOA, it can be assumed that the same is true of GOA prevalence.
Subject(s)
Osteoarthritis/genetics , Adult , Arthrography , Female , Finger Joint/physiopathology , Humans , Joints/physiopathology , Male , Middle Aged , Osteoarthritis/diagnosis , Osteoarthritis/physiopathology , Osteoarthritis, Hip/diagnosis , Osteoarthritis, Hip/genetics , Osteoarthritis, Hip/physiopathology , Osteoarthritis, Knee/diagnosis , Osteoarthritis, Knee/genetics , Osteoarthritis, Knee/physiopathology , Range of Motion, Articular/physiology , Spine/physiopathologyABSTRACT
BACKGROUND: The appropriate management of the pancreatic remnant following distal pancreatic resection remains a clinically relevant problem. We carried out a retrospective analysis which focused on this issue and compared the two favored techniques of suture and staple closure. PATIENTS AND METHODS: Forty-six patients underwent distal pancreatectomy between October 1999 and January 2006. The patients were retrospectively analysed based on the management of the remaining pancreatic gland. Thirty-seven patients had suture and nine patients had staple closure. The morbidity, mortality, incidence of pancreatic fistula, necessity of secondary surgical intervention, and the duration of hospital stay for the two groups were compared. Pancreatic fistula was considered according to the novel international standard definition (ISGPF). In addition, subgroup analysis of patients receiving octreotide was carried out. RESULTS: Overall, postoperative morbidity due to pancreatic fistula occurred in seven patients (19%) after suture and in one patient (11%) after staple closure (p = 0.54), with no deaths. The number of patients with surgical revision related to pancreatic leakage was two (5%) after suture closure vs no revision after staple closure (p = 0.65). The median number of total hospital days for the suture group was 19 (range 7-78 days) vs 21 (range 12-96 days) for the stapler group (p = 0.21). No significant benefit for the octreotide application could be determined. CONCLUSION: According to the data, no significant difference for either suture or stapler closure was observed, with the tendency for staple closure to be superior.