Can the transection plane be optimized in pancreatic resections?

Purpose: According to current protocol, the separation of pancreatic head and body is performed at the level of superior mesenteric vein (SMV). Previous data indicate that the resection plane should be modified in portal annular pancreas. We presumed that the optimal line of pancreatic resections could also be different in other cases. Our aim is to simulate pancreatic resections in different planes and find the optimal resection line with the minimum number of cut vessels. Main methods: 25 abdominal vascular corrosion casts were prepared, the aorta and the portal vein were cannulated. CT scans were taken on the casts, and specific planes were reconstructed simulating different resection lines. The total amount of cross sections of vessels were calculated in the different planes. Results: In our series, the optimal plane is the SMV in 11/25, 2 cm left in 10/25, 1 cm left in 4/25, 1 cm right in 1/25 and 2 cm right in none of our cases. The group of left sided extension contain more than half of the cases. With left sided resections, the cut surface of the vessels may be lowered to even 29% compared to the SMV plane. Conclusion: Our study revealed that pancreatic resections should be extended to the left side of the SMV in more than half of our cases. Therefore, the resection plane should be determined by preoperative imaging methods. Using DICOM viewer with multiplanar reconstruction, the resection planes can be simulated in clinical practice, which would reduce the risk of postoperative bleeding.

Large-magnitude (VEI ≥ 7) 'wet' explosive silicic eruption preserved a Lower Miocene habitat at the Ipolytarnóc Fossil Site, North Hungary.

During Earth's history, geosphere-biosphere interactions were often determined by momentary, catastrophic changes such as large explosive volcanic eruptions. The Miocene ignimbrite flare-up in the Pannonian Basin, which is located along a complex convergent plate boundary between Europe and Africa, provides a superb example of this interaction. In North Hungary, the famous Ipolytarnóc Fossil Site, often referred to as "ancient Pompeii", records a snapshot of rich Early Miocene life buried under thick ignimbrite cover. Here, we use a multi-technique approach to constrain the successive phases of a catastrophic silicic eruption (VEI ≥ 7) dated at 17.2 Ma. An event-scale reconstruction shows that the initial PDC phase was phreatomagmatic, affecting ≥ 1500 km2 and causing the destruction of an interfingering terrestrial-intertidal environment at Ipolytarnóc. This was followed by pumice fall, and finally the emplacement of up to 40 m-thick ignimbrite that completely buried the site. However, unlike the seemingly similar AD 79 Vesuvius eruption that buried Pompeii by hot pyroclastic density currents, the presence of fallen but uncharred tree trunks, branches, and intact leaves in the basal pyroclastic deposits at Ipolytarnóc as well as rock paleomagnetic properties indicate a low-temperature pyroclastic event, that superbly preserved the coastal habitat, including unique fossil tracks.

Increment in the volcanic unrest and number of eruptions after the 2012 large earthquakes sequence in Central America.

Understanding the relationship cause/effect between tectonic earthquakes and volcanic eruptions is a striking topic in Earth Sciences. Volcanoes erupt with variable reaction times as a consequence of the impact of seismic waves (i.e. dynamic stress) and changes in the stress field (i.e. static stress). In 2012, three large (Mw ≥ 7.3) subduction earthquakes struck Central America within a period of 10 weeks; subsequently, some volcanoes in the region erupted a few days after, while others took months or even years to erupt. Here, we show that these three earthquakes contributed to the increase in the number of volcanic eruptions during the 7 years that followed these seismic events. We found that only those volcanoes that were already in a critical state of unrest eventually erupted, which indicates that the earthquakes only prompted the eruptions. Therefore, we recommend the permanent monitoring of active volcanoes to reveal which are more susceptible to culminate into eruption in the aftermath of the next large-magnitude earthquake hits a region.

Radical anion functionalization of two-dimensional materials as a means of engineering simultaneously high electronic and ionic conductivity solids.

A radical anion based functionalization of the basal plane of hexagonal boron nitride (h-BN) and other two-dimensional materials is proposed in the present study. The resulting materials can reversibly be oxidized without the detachment of the functional groups from the basal plane and can thus serve as surface-intercalation type cathode electroactive species and fast solid ion conductors at the same time. The functionalization of h-BN with [·OBX3]- radical anions (X=F, Cl) in the presence of Li, Na or Mg cations provides one example of such systems. This material can be realized in a proposed simple, two step synthesis. In the first step, a symmetric Lewis adduct of the corresponding Li, Na or Mg peroxides is formed with BX3. In the second step, the anion of the Lewis adduct is thermally split into two identical [·OBX3]- radical anions that covalently functionalize the B atoms of h-BN. In the maximum density surface packing functionalization, the product of the synthesis is A n [(BN)2OBX3] (A = Li, Na with n = 1 or A = Mg with n = 0.5). Its ionic conductivity is predicted to be in the order of 0.01-0.1 S cm-1 at room temperature, on the basis of Grotthus-like (or paddle-wheel) ion transport. In the highly oxidized states (0 ≤ n ≤ 1 for Li and Na and 0 ≤ n ≤ 0.5 for Mg), the electronic conductivity of this material is in the order of 1 S cm-1, similar to carbon black. In the fully reduced states (n = 2 for Li and Na and n = 1 for Mg), the material becomes an insulator, like h-BN. The tunability of the electronic properties of A n [(BN)2OBX3] via the cation concentration (n) allows for its application as multifunctional material in energy storage devices, simultaneously serving as cathode active species, solid electrolyte, electroconductive additive, separator, heat conductor and coating for metal anodes that enables dendrite-free plating. This multifunctionality reduces the number of phases needed in an all-solid-state battery or supercapacitor and thus reduces the interfacial impedance making energy storage devices more efficient. For example, Li[(BN)2OBF3] is predicted to have 5.6 V open circuit voltage versus Li metal anode, capacity of 191 mAh g- 1, specific energy of 1067 Wh kg- 1 and can store energy at a (materials only) cost of 24 USD kWh- 1.

Radical Anion Functionalization of Two-Dimensional Materials as a Means ofEngineering Simultaneously High Electronic and Ionic Conductivity Solids.

A radical anion based functionalization of the basal plane of hexagonal boron nitride (h-BN) and other two-dimensional (2D) materials is proposed in the present study. The resulting materials can reversibly be oxidized without the detachment of the functional groups from the basal plane and can thus serve as surface-intercalation type cathode electroactive species and fast solid ion conductors at the same time. The functionalization of h-BN with [·OBX3]-radical anions (X=F,Cl) in the presence of Li, Na or Mg cations provides one example of such systems. This material can be realized in a proposed simple, two step synthesis. In the first step, a symmetric Lewis adduct of the corresponding Li, Na or Mg peroxides is formed with BX3. In the second step, the anion of the Lewis adduct is thermally split into two identical [·OBX3]-radical anions that covalently functionalize the B atoms of h-BN. In the maximum density surface packing functionalization, the product of the synthesis is An[(BN)2OBX3] (A=Li,Na with n=1 or A=Mg with n=0.5). In the highly oxidized states (0≤n≤1 for Li and Na and 0≤n≤0.5 for Mg), the electronic conductivity of this material is in the order of 1 S/cm, similar to carbon black. In the fully reduced states (n=2 for Li and Na and n=1 for Mg), the material becomes an insulator, like h-BN. The tunability of the electronic properties of An[(BN)2OBX3] via the cation concentration allows for its application as multifunctional material in energy storage devices, simultaneously serving as cathode active species, solid electrolyte, electroconductive additive, separator, heat conductor and coating for metal anodes that enables dendrite-free plating. This multifunctionality reduces the number of phases needed in an all-solid-state battery or supercapacitor and thus reduces the interfacial impedance making energy storage devices more efficient. For example, Li[(BN)2OBF3] is predicted to have 5.6 V open circuit voltage vs Li metal anode, capacity of 191 mAh/g, specific energy of 1067 Wh/kg and can store energy at a (materials only) cost of 24 USD/kWh.

[Small bowel perforation caused by intestinal dissemination of pulmonary tuberculosis due to biological therapy]. / Biológiai terápiát követoen fellángoló pulmonalis tbc enterális disszeminációja által okozott vékonybél-perforatio.

Case review: The authors present a case of a 78-year-old female patient who previously, as a teenager, had been treated for pulmonary tuberculosis. The biological therapy for subsequent inflammatory bowel disease in 2015 caused a flare up of the respiratory symptoms after 60 years of being asymptomatic, and the patient also developed acute abdomen. She required emergency laparotomy and small intestine segment resection was performed due to perforated ileum. Histological examination of the specimen showed intestinal tuberculosis as the cause of perforation. Following pharmacological therapy in the postoperative period the patient eventually became asymptomatic. Discussion: Tuberculosis is a life threatening disease which can virtually affect any organ system. The primary site of tuberculosis is usually the lung, from which it can get disseminated into other parts of the body. With this article we would like to raise the awareness of the potentially lethal side effects of biological and immune modulated therapies and we would also like to emphasize the importance of the cooperation of practitioners in different medical fields.

Weka Trainable Segmentation Plugin in ImageJ: A Semi-Automatic Tool Applied to Crystal Size Distributions of Microlites in Volcanic Rocks.

Crystals within volcanic rocks record geochemical and textural signatures during magmatic evolution before eruption. Clues to this magmatic history can be examined using crystal size distribution (CSD) studies. The analysis of CSDs is a standard petrological tool, but laborious due to manual hand-drawing of crystal margins. The trainable Weka segmentation (TWS) plugin in ImageJ is a promising alternative. It uses machine learning and image segmentation to classify an image. We recorded back-scattered electron (BSE) images of three volcanic samples with different crystallinity (35, 50 and ≥85 vol. %), using scanning electron microscopes (SEM) of variable image resolutions, which we then tested using TWS. Crystal measurements obtained from the automatically segmented images are compared with those of the manual segmentation. Samples up to 50 vol. % crystallinity are successfully segmented using TWS. Segmentation at significantly higher crystallinities fails, as crystal boundaries cannot be distinguished. Accuracy performance tests for the TWS classifiers yield high F-scores (>0.930), hence, TWS is a successful and fast computing tool for outlining crystals from BSE images of glassy rocks. Finally, reliable CSD's can be derived using a low-cost desktop SEM, paving the way for a wide range of research to take advantage of this new petrological method.

Pancreaticoduodenal arterial arcades: Their dominance and variations-their potential clinical relevance.

The complex arterial system makes pancreatic interventions technically challenging for surgeons, and interventional radiologists. The arterial variants may alter tumor resecability, and cause complications in arterial embolization. International data on pancreatic blood supply are variable; therefore, we aimed to determine the frequency of variants of pancreaticoduodenal (PD) arterial arcades. Arteries of human abdominal organ complexes (50) were injected with resin mixture, and then corroded. CT scans and three-dimensional reconstructions were made; diameters of arcades were measured. Two PD arcades were found in 58%, three arcades in 30%, one arcade in three cases, four arcade in one specimen, and five arcades in two cases. In the casts with two arches the average diameter was 1.472 ± 0.432 mm on the anterior and 1.383 ± 0.343 mm on the posterior arch. Assessing the dominance of the PD arcades, the anterior arch proved to be dominant in 52% of the cases, and in 35% the posterior one by the criterion of 25% cross-section difference. It is advised to analyze the variations and dominance on a CT/MR-angiography before local chemotherapy. Furthermore, to reveal the arterial variations, a preoperative CT/MR-angiography would provide faster recuperation and better postoperative life quality. Clin. Anat. 31:544-550, 2018. © 2018 Wiley Periodicals, Inc.

Extrahepatic arteries of the human liver - anatomical variants and surgical relevancies.

The purpose of our study was to investigate the anatomical variations of the extrahepatic arterial structures of the liver with particular attention to rare variations and their potential impact on liver surgery. A total of 50 human abdominal organ complexes were used to prepare corrosion casts. A multicomponent resin mixture was injected into the abdominal aorta. The portal vein was injected with a different colored resin in 16 cases. Digestion of soft tissues was achieved using cc. KOH solution at 60-65 °C. Extrahepatic arterial variations were classified according to Michels. All specimens underwent 3D volumetric CT reconstruction. Normal anatomy was seen in 42% of cases, and variants were seen in the other 58%. No Michels type VI or X variations were present; however, in 18% of cases the extrahepatic arterial anatomy did not fit into Michels' classification. We report four new extrahepatic arterial variations. In contrast to the available data, normal anatomy was found much less frequently, whereas the prevalence of unclassified arterial variations was higher. We detected four previously unknown variations. Our data may contribute to the reduction of complications during surgical and radiological interventions in the upper abdomen.

Optimal line of hepatotomy for left lateral living donor liver transplantation according to the anatomical variations of left hepatic duct system.

Multiple duct anastomoses during LLS transplantation increase the incidence of biliary complications. The optimal plane of hepatotomy that results in the least number of bile ducts at the surface was investigated according to LHD variations. Ducts of 30 human livers were injected with resin and LHD branching on 3D-CT reconstructions were analyzed. Ducts on the virtual hepatotomy surface were estimated in three splitting lines. Variations with subtypes were described. Ia (66.7%): ducts from segments (S.) II-III form a common trunk and S.IV duct joins it. Ib (10%): common trunk formed by ducts from S.II-S.III while S.IV duct joins the common hepatic duct. IIa (16.67%): S.IV duct drains into S.III duct. IIc (3.33%): S.IV duct drains into both S.II and S.III ducts. III (3.33%): trifurcation of S.II, S.III and S.IV ducts. When the virtual hepatotomy line was on the FL, there was a single duct for the anastomosis in 30% of cases but two, three, or four ducts in 53.3%, 10%, and 3.3%, respectively. Division 1 cm to the right of the FL resulted in one duct (70%), but S.IV duct injury may occur. LLS hepatotomy should not necessarily be performed along the FL. Variations must be taken into consideration to minimize the number of biliary anastomoses during liver implantation.

Ultrahigh energy density Li-ion batteries based on cathodes of 1D metals with -Li-N-B-N- repeating units in α-Li(x)BN2 (1 ⩽ x ⩽ 3).

Ultrahigh energy density batteries based on α-Li(x)BN2 (1 ⩽ x ⩽ 3) positive electrode materials are predicted using density functional theory calculations. The utilization of the reversible LiBN2 + 2 Li(+) + 2 e(-) ⇌ Li3BN2 electrochemical cell reaction leads to a voltage of 3.62 V (vs Li/Li(+)), theoretical energy densities of 3251 Wh/kg and 5927 Wh/l, with capacities of 899 mAh/g and 1638 mAh/cm(3), while the cell volume of α-Li3BN2 shrinks only 2.8% per two-electron transfer on charge. These values are far superior to the best existing or theoretically designed intercalation or conversion-based positive electrode materials. For comparison, the theoretical energy density of a Li-O2/peroxide battery is 3450 Wh/kg (including the weight of O2), that of a Li-S battery is 2600 Wh/kg, that of Li3Cr(BO3)(PO4) (one of the best designer intercalation materials) is 1700 Wh/kg, while already commercialized LiCoO2 allows for 568 Wh/kg. α-Li3BN2 is also known as a good Li-ion conductor with experimentally observed 3 mS/cm ionic conductivity and 78 kJ/mol (≈0.8 eV) activation energy of conduction. The attractive features of α-Li(x)BN2 (1 ⩽ x ⩽ 3) are based on a crystal lattice of 1D conjugated polymers with -Li-N-B-N- repeating units. When some of the Li is deintercalated from α-Li3BN2 the crystal becomes a metallic electron conductor, based on the underlying 1D conjugated π electron system. Thus, α-Li(x)BN2 (1 ⩽ x ⩽ 3) represents a new type of 1D conjugated polymers with significant potential for energy storage and other applications.

Metal-insulator photocathode heterojunction for directed electron emission.

We use angle-resolved photoemission under ultraviolet laser excitation to demonstrate that the electron emission properties of Ag(001) can be markedly enhanced and redirected along the surface normal by the deposition of a few monolayers of epitaxial MgO. We observe new low-binding energy states with small spreads in their surface parallel momenta as a result of MgO/Ag(001) interface formation. Under 4.66 eV laser excitation, the quantum efficiency of MgO/Ag(001) is a factor of 7 greater than that of clean Ag(001), revealing the utility of such heterojunctions as advanced photocathodes.

Collateral circulation of the rat lower limb and its significance in ischemia-reperfusion studies.

PURPOSE: Rats are the most commonly used animal model for studies of acute lower limb ischemia-reperfusion. The ischemia induced by arterial clamping may cause milder damage than the application of a tourniquet if the presence of a possible collateral system is considered. METHODS: Male Wistar rats were randomized into three groups: in group A, the muscle weight affected by ischemia was measured; in group B, the severity of muscle damage caused by the application of a tourniquet and by infrarenal aortic occlusion was examined. Blood and muscle samples were taken from group B to assess the serum necroenzyme, potassium and TNF-α levels, as well as the muscle fiber viability and for histological examinations. In group C, the identification of the lower limb collateral system was performed using corrosion casting. RESULTS: Tourniquet application affected the lower muscle mass and resulted in significantly more severe injury compared to infrarenal aortic occlusion. This difference was reflected in the serum necroenzyme, potassium and TNF-α levels. The histological examination and viability assay confirmed these findings. The corrosion casts showed several anastomoses capable of supplying the lower limb. CONCLUSION: Tourniquet application proved to be capable of inducing absolute lower limb ischemia, in contrast to infrarenal aortic ligation, where a rich collateral system is considered to help mitigate the injury.

Efficient simultaneous reverse Monte Carlo modeling of pair-distribution functions and extended x-ray-absorption fine structure spectra of crystalline disordered materials.

An efficient implementation of simultaneous reverse Monte Carlo (RMC) modeling of pair distribution function (PDF) and EXAFS spectra is reported. This implementation is an extension of the technique established by Krayzman et al. [J. Appl. Cryst. 42, 867 (2009)] in the sense that it enables simultaneous real-space fitting of x-ray PDF with accurate treatment of Q-dependence of the scattering cross-sections and EXAFS with multiple photoelectron scattering included. The extension also allows for atom swaps during EXAFS fits thereby enabling modeling the effects of chemical disorder, such as migrating atoms and vacancies. Significant acceleration of EXAFS computation is achieved via discretization of effective path lengths and subsequent reduction of operation counts. The validity and accuracy of the approach is illustrated on small atomic clusters and on 5500-9000 atom models of bcc-Fe and α-Fe(2)O(3). The accuracy gains of combined simultaneous EXAFS and PDF fits are pointed out against PDF-only and EXAFS-only RMC fits. Our modeling approach may be widely used in PDF and EXAFS based investigations of disordered materials.

High-brightness photocathodes through ultrathin surface layers on metals.

We report how ultrathin MgO films on Ag(001) surfaces can be used to control the emittance properties of photocathodes. In addition to substantially reducing the work function of the metal surface, the MgO layers also favorably influence the shape of the surface bands resulting in the generation of high-brightness electron beams. As the number of MgO surface layers varies from 0 to 3, the emitted electron beam becomes gradually brighter, reducing its transverse emittance to 0.06 mm mrad. We suggest the use of such photocathodes for the development of free-electron x-ray lasers and energy-recovery linac x-ray sources.

Trace correcting density matrix extrapolation in self-consistent geometry optimization.

A linear scaling trace correcting density matrix extrapolation method is proposed for accelerated self-consistency convergence in geometry optimization. The technique is based on nonorthogonal trace correcting purification and perturbation theory. Compared with alternative schemes, extrapolated total energies are often an order of magnitude closer to the self-consistent solution. For insulators, the computational cost is low and it scales linearly with the size of the perturbed region affected by the modified geometry, O(N(pert)). For local perturbations, the computational cost is therefore independent of the total size of the system and scales as O(1).

The choice of internal coordinates in complex chemical systems.

This article presents several considerations for the appropriate choice of internal coordinates in various complex chemical systems. The appropriate and black box recognition of internal coordinates is of fundamental importance for the extension of internal coordinate algorithms to all fields where previously Cartesian coordinates were the preferred means of geometry manipulations. Such fields range from local and global geometry optimizations to molecular dynamics as applied to a wide variety of chemical systems. We present a robust algorithm that is capable to quickly determine the appropriate choice of internal coordinates in a wide range of atomic arrangements.

Laser-driven coherent betatron oscillation in a laser-wakefield cavity.

The origin of beam disparity in emittance and betatron oscillation orbits, in and out of the polarization plane of the drive laser of laser-plasma accelerators, is explained in terms of betatron oscillations driven by the laser field. As trapped electrons accelerate, they move forward and interact with the laser pulse. For the bubble regime, a simple model is presented to describe this interaction in terms of a harmonic oscillator with a driving force from the laser and a restoring force from the plasma wake field. The resulting beam oscillations in the polarization plane, with period approximately the wavelength of the driving laser, increase emittance in that plane and cause microbunching of the beam. These effects are observed directly in 3D particle-in-cell simulations.

Geometry optimization of crystals by the quasi-independent curvilinear coordinate approximation.

The quasi-independent curvilinear coordinate approximation (QUICCA) method [K. Nemeth and M. Challacombe, J. Chem. Phys. 121, 2877 (2004)] is extended to the optimization of crystal structures. We demonstrate that QUICCA is valid under periodic boundary conditions, enabling simultaneous relaxation of the lattice and atomic coordinates, as illustrated by tight optimization of polyethylene, hexagonal boron nitride, a (10,0) carbon nanotube, hexagonal ice, quartz, and sulfur at the Gamma-point RPBE/STO-3G level of theory.