Apparent Leakage Research Articles

Study of the Mechanism of Liquid‐Metal‐Assisted Thermal Interface Materials

With the increase in power consumption of integrated circuits, thermal interface materials (TIMs) attract significant attention. Liquid metal (LM) is an emerging high thermal conductive TIM, because of its excellent rheological properties which are helpful to fill micro gaps existing in a thermal interface. However, due to the apparent leakage hazard of pure LM, they are usually mixed with other materials for applications. In this work, the thermal resistance of silicone oil mixed with LM is about five times lower than that of it mixed with AlN powder of the same volume. This is a counterintuitive fact as the intrinsic thermal conductivity of LM is ≈20 Wm−1 K−1, which is more than ten times lower than AlN's thermal conductivity of 260–320 Wm−1 K−1. In this study, it is suggested that the reason can be attributed to deformed LM and their wetting process on the interface. Moreover, when introducing high load (83 vol%) LM or simultaneously introducing LM and AlN (sum‐load 83 vol%) in silicone oil, these composites achieve high thermal conductivity, low thermal resistance, and good compressibility. In practical application, the SO + LM + AlN composites also show much better heat‐dissipation ability than commercial thermal grease.

Pulsatile flow of biviscous fluid through a tube of varying cross-section

In this paper, a pulsatile flow of a biviscous fluid in a circular tube of varying cross-section has been considered for investigation. The study helps to draw the characteristics of blood, the pressure drop and the wall shear stress on the inner wall of small blood vessels and capillaries where suction/injection velocity arises and Reynolds number is very low. The effects of Reynolds number, apparent viscosity coefficient and leakage parameter on the streamlines, pressure drop and wall shear stress have been discussed and shown graphically for suction and injection, respectively. The wall of the tube is supposed to be permeable and a normal velocity of the fluid at the wall is prescribed to consider the fluid exchange across the wall. Both analytic and numerical solutions are given. Using the perturbation technique, we analyze the problem for low Reynolds numbers and small oscillation amplitude. Lastly, the simulations are given to demonstrate the effectiveness and excellent tracking performance of the proposed control scheme.

Dual Pigment Epithelium-derived Factor and Hepatocyte Growth Factor Overexpression: A New Therapy for Pulmonary Hypertension.

Pulmonary hypertension (PH) is a disease characterized by advanced pulmonary vasculature remodeling that is thought to be curable only through lung transplantation. The application of angiogenic hepatocyte growth factor (HGF) is reported to be protective in PH through its anti-vascular remodeling effect, but excessive HGF-mediated immature neovascularization is not conducive to the restoration of pulmonary perfusion because of apparent vascular leakage. As a canonical antiangiogenic molecule, pigment epithelium-derived factor (PEDF) inhibits angiogenesis and reduces vascular permeability in a variety of diseases. However, the effect of PEDF on HGF-based PH treatment remains to be determined. In this study, monocrotaline-induced PH rats and endothelial cells isolated from rat and human PH lung tissues were used. We assessed PH progression, right cardiac function, and pulmonary perfusion in HGF- and/or PEDF-treated rats with PH. Additionally, the receptor and mechanism responsible for the role of PEDF in HGF-based PH therapy were investigated. In this study, we found that HGF and PEDF jointly prevent PH development and improve right cardiac function in rats with PH. Moreover, PEDF delivery increases the pulmonary perfusion in PH lungs and inhibits immature angiogenesis and vascular endothelial (VE)-cadherin junction disintegration induced by HGF without affecting the therapeutic inhibition of pulmonary vascular remodeling by HGF. Mechanistically, PEDF targets VE growth factor receptor 2 and suppresses its phosphorylation at Y951 and Y1175 but not Y1214. Finally, VE growth factor receptor 2/VE protein tyrosine phosphatase/VE-cadherin complex formation and Akt and Erk1/2 inactivation were observed in rat and human PH lung endothelial cells. Collectively, our data indicate that PEDF additively enhances the efficacy of HGF against PH, which may provide new insights into treatment strategies for clinical PH.

Analysis of IPT Intermediate Coupler System for Vehicle Charging Over Large Air Gaps

Intermediate resonant pads have been recently used to increase the ground clearance for inductive power transfer (IPT) systems transferring power over large air gaps. This article investigates the best placement of a tuned intermediate pad to maximize the air gap by assessing the leakage magnetic fields and the apparent power effort. A mathematical analysis is used to design and control a two-coil system with an intermediate pad. The results show that SAE J2954 standard pads can transfer rated power over an extended air gap of 406 mm using an intermediate pad while adhering to the apparent power ratings of all pads and typical leakage constraints. As a comparison, an equivalent IPT system using only a primary and a secondary pad without the intermediate pad is shown to be unable to meet the apparent power and leakage requirements at these large air gaps. Additionally, this article shows and validates control and regulation of the intermediate pad and load current by switching the secondary side.

Leaky membrane fusion: an ambivalent effect induced by antimicrobial polycations.

Both antimicrobial peptides and their synthetic mimics are potential alternatives to classical antibiotics. They can induce several membrane perturbations including permeabilization. Especially in model studies, aggregation of vesicles by such polycations is often reported. Here, we show that unintended vesicle aggregation or indeed fusion can cause apparent leakage in model studies that is not possible in most microbes, thus potentially leading to misinterpretations. The interactions of a highly charged and highly selective membrane-active polycation with negatively charged phosphatidylethanolamine/phosphatidylglycerol (PE/PG) vesicles are studied by a combination of biophysical methods. At low polycation concentrations, apparent vesicle aggregation was found to involve exchange of lipids. Upon neutralization of the negatively charged vesicles by the polycation, full fusion and leakage occurred and leaky fusion is suspected. To elucidate the interplay of leakage and fusion, we prevented membrane contacts by decorating the vesicles with PEG-chains. This inhibited fusion and also leakage activity. Leaky fusion is further corroborated by increased leakage with increasing likeliness of vesicle-vesicle contacts. Because of its similar appearance to other leakage mechanisms, leaky fusion is difficult to identify and might be overlooked and more common amongst polycationic membrane-active compounds. Regarding biological activity, leaky fusion needs to be carefully distinguished from other membrane permeabilization mechanisms, as it may be less relevant to bacteria, but potentially relevant for fungi. Furthermore, leaky fusion is an interesting effect that could help in endosomal escape for drug delivery. A comprehensive step-by-step protocol for membrane permeabilization/vesicle leakage using calcein fluorescence lifetime is provided in the ESI.

Autogenous Healing in Ultra-High-Performance Fibre Reinforced Concrete: application in two reduced scale water reservoirs

Self-healing is defined as the capacity of a material to repair internal damage without any external intervention. In the case of concrete, this process can be autogenous, which is the natural capacity of the material. Ultra-High-Performance Fibre Reinforced Concrete (UHPFRC) has a high self-healing potential due to its high binder content with a low w/b ratio and its crack pattern with multiple micro cracks. This paper describes two UHPFRC water reservoirs, which were designed to minimise the volume of concrete used. The design is made of ribbed thin walls where shrinkage cracks are likely to happen. The objective of this work is to study the autogenous healing capability of this concrete in these cracks. The two water reservoirs have internal dimensions of 1.30×0.75×0.70 m³ and with 20 mm thickness in the centre of the walls. These walls displayed cracks (w < 100 μm), which were produced just after casting. Both reservoirs were filled with water, showing apparent water leakage. The cracks were monitored for 30 days, analysing pictures taken with an optical microscope. The results show that UHPFRC is able to heal autogenously under the conditions in this work, recovering completely the water tightness required for the water reservoirs.

Influence of Sheath Radial Crack on Flashover Arc and Leakage Current of Roof Silicon Rubber Insulator for High-Speed Train

In this paper, three types of insulators with no crack, short crack, and long crack are taken as the research objects to evaluate the influence of the penetrating cracks on the 1 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sup> sheath of the roof silicone rubber composite insulator of high-speed train on the flashover characteristics. The continuous voltage rising method is used to obtain the influence characteristics of the crack on the development process of the flashover arc. The constant voltage withstand method is adopted to compare the leakage current when the contamination degree is 0.1 mg/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The test results demonstrate that the crack has no significant effect on the flashover voltage and flashover path, and the flashover arc can burn the edge of the crack. The peak leakage current of the three different tests ranges from 24 mA to 30 mA. Additionally, the development of leakage current can be divided into four stages: rising, continuous violence, falling, and oscillating. Moreover, the sequence of the apparent leakage current of the insulator is long crack insulator, short crack insulator, and the one with no crack. The acceleration of the rising stage of the leakage current increases with the increase in the crack length. Meanwhile, the sum of the time of the rising stage, continuous stage, and falling stage of the insulator with long crack is the smallest. The crack will distort the distribution of current density and the electric field intensity in the vicinity. The results can provide references for evaluating the influence of radial cracks at the edge of the sheath on the flashover characteristics and optimizing the design of the roof insulator sheath structure.

A perennial invader’s seed and rhizome differ in cold tolerance and apparent local adaptation

Extreme cold plays a key role in the range boundaries of plants. Winter survival is central to their persistence, but not all structures are equally susceptible to frost kill and, therefore, limiting to distributions. Furthermore, we expect intraspecific variation in cold tolerance both within and among tissue types. In a laboratory setting, we determined freezing tolerances of two overwintering propagule types – seeds and rhizomes – of the globally invasive Johnsongrass (Sorghum halepense), testing apparent emergence and electrolyte leakage as a proxy for cell death. We used 18 genotypes from agricultural and non-agricultural habitats spanning the climatic extremes occupied by Johnsongrass in the US. Single node rhizome fragments had an average LT90 of -5.1 °C with no significant variation based on home climate or ecotype. Seeds frozen at -85 °C suffered a decline in germinability to 10% from 25% at 22 °C. Population origin did not affect seed response to any temperature. However, non-agricultural seeds germinated more and faster than agricultural seeds from the coldest climates, with a reversed relationship among warmest origin seeds. Regardless of ecotype, seeds from the cold/dry and wet/warm sectors of Johnsongrass’s range germinated more and faster. Drastic differences in cold tolerance between seeds and rhizome and evidence for seeds’ local adaptation to land use and climate suggest that its spread is likely limited by winter rhizome survival, as well as adaptability of germination behavior to longer winters. These findings shed light on Johnsongrass’ dispersal dynamics and help identify future avenues for mechanistically understanding its range limitation.

Electron and proton transport in wheat exposed to salt stress: is the increase of the thylakoid membrane proton conductivity responsible for decreasing the photosynthetic activity in sensitive genotypes?

Effects of salinity caused by 150 mM NaCl on primary photochemical reactions and some physiological and biochemical parameters (K+/Na+ ratio, soluble sugars, proline, MDA) have been studied in five Triticum aestivum L. genotypes with contrasting salt tolerance. It was found that 150 mM NaCl significantly decreased the photosynthetic efficiency of two sensitive genotypes. The K+/Na+ ratio decreased in all genotypes exposed to salinity stress when compared with the control. Salinity stress also caused lipid peroxidation and accumulation of soluble sugars and proline. The amounts of soluble sugars and proline were higher in tolerant genotypes than sensitive ones, and lipid peroxidation was higher in sensitive genotypes. The noninvasive measurements of photosynthesis-related parameters indicated the genotype-dependent effects of salinity stress on the photosynthetic apparatus. The significant decrease of chlorophyll content (SPAD values) or adverse effects on photosynthetic functions at the PSII level (measured by the chlorophyll fluorescence parameters) were observed in the two sensitive genotypes only. Although the information obtained by different fast noninvasive techniques were consistent, the correlation analyses identified the highest correlation of the noninvasive records with MDA, K+/Na+ ratio, and free proline content. The lower correlation levels were found for chlorophyll content (SPAD) and Fv/Fm values derived from chlorophyll fluorescence. Performance index (PIabs) derived from fast fluorescence kinetics, and F735/F685 ratio correlated well with MDA and Na+ content. The most promising were the results of linear electron flow measured by MultispeQ sensor, in which we found a highly significant correlation with all parameters assessed. Moreover, the noninvasive simultaneous measurements of chlorophyll fluorescence and electrochromic band shift using this sensor indicated the apparent proton leakage at the thylakoid membranes resulting in a high proton conductivity (gH+), present in sensitive genotypes only. The possible consequences for the photosynthetic functions and the photoprotection are discussed.

Annealing effect of pentacene and ultrathin metal anode buffer on the performance of small-molecule organic solar cells

The annealing effect of thin pentacene and ultrathin gold/silver anode buffer layers on both the initial performance and durability against repetitive illumination stress in small-molecule organic solar cells (OSCs) was experimentally investigated. The OSC had a structure of indium tin oxide (ITO, anode)/anode buffer/copper phthalocyanine (CuPc, donor)/fullerene (acceptor)/bathocuproine (cathode buffer)/Ag (cathode). OSCs with a 3-nm-thick pentacene anode buffer layer provided a 15% increase in the power conversion efficiency compared to OSCs with no pentacene layer. OSCs with an ultrathin 0.3-nm-thick Au anode buffer layer provided an increase of 63% in durability compared to OSCs without the Au layer. OSCs with the Au layer did not show apparent leakage current, while those with the Ag layer did. OSCs with a combinational anode buffer of the pentacene layer/Au layer were mainly examined. The spatial distribution of Au atoms on pentacene was uniform even after annealing, which helped to improve the quality of CuPc crystals. The ultrathin Au layer brought both a large absorption of ultraviolet (UV) light and highly dense nucleation sites for overlaid CuPc film formation. These were possible reasons for durability improvement. The Au layer thickness of 0.3 nm on pentacene was optimal to achieve the condition with both less attenuation of visible light necessary for electric power generation and larger absorption of UV light causing degradation. Annealing treatment before CuPc evaporation brought both preferable initial performance and durability for OSCs with a combinational structure of the ITO/pentacene layer/Au layer. An appropriate region of annealing temperature had, however, a small window around 100°C.

Electrochemical Processing and Thermal Properties of Functional Core/Multi-Shell ZnAl/Ni/NiP Microparticles.

Electroless deposition on zinc and its alloys is challenging because of the negative standard potential of zinc, the formation of poor surface layers during oxidation in aqueous solutions, and extensive hydrogen evolution. Therefore, there are only few reports of electroless deposition on Zn and its alloys, neither of them on micro/nano powders. Here, we propose a two-step process that allows the formation of compact, uniform, and conformal Ni/NiP shell on Zn-based alloy microparticles without agglomeration. The process utilizes controlled galvanic displacement of Ni deposition in ethanol-based bath, followed by NiP autocatalytic deposition in an alkaline aqueous solution. The mechanism and effect of deposition conditions on the shell formation are discussed. Thermal stability and functional analysis of core-shell powder reveal a thermal storage capability of 98.5% with an encapsulation ratio of 66.5%. No significant morphological change of the core-shell powder and no apparent leakage of the ZnAl alloy through the Ni shell are evident following differential scanning calorimetry tests. Our two-step process paves the way to utilize electroless deposition for depositing metallic-based functional coatings on Zn-based bulk and powder materials.

Endothelial Microvesicles Induce Pulmonary Vascular Leakage and Lung Injury During Sepsis.

Sepsis is a prevalent severe syndrome in clinic. Vascular leakage and lung injury are important pathophysiological processes during sepsis, but the mechanism remains obscure. Microvesicles (MVs) play an essential role in many diseases, while whether MVs participate in vascular leakage and lung injury during sepsis is unknown. Using cecal ligation and puncture induced sepsis rats and lipopolysaccharide stimulated vascular endothelial cells (VECs), the role and the underlying mechanism of endothelial microvesicles (EMVs) in pulmonary vascular leakage and lung injury were observed. The role of MVs from sepsis patients was verified. The results showed that the concentration of MVs in blood was significantly increased after sepsis. MVs from sepsis rats and patients induced apparent pulmonary vascular leakage and lung injury, among which EMVs played the dominant role, in which miR-23b was the key inducing factor in vascular leakage. Furthermore, downregulation and upregulation of miR-23b in EMVs showed that miR-23b mainly targeted on ZO-1 to induce vascular leakage. MVs from sepsis patients induced pulmonary vascular leakage and lung injury in normal rats. Application of classic antidepressants amitriptyline reduced the secretion of EMVs, and alleviated vascular leakage and lung injury. The study suggests that EMVs play an important role in pulmonary vascular leakage and lung injury during sepsis by transferring functional miR-23b. Antagonizing the secretion of EMVs and the miR-23b might be a potential target for the treatment of severe sepsis.

EphrinA1/EphA2 Promotes Epithelial Hyperpermeability Involving in Lipopolysaccharide-induced Intestinal Barrier Dysfunction.

Background/AimsLipopolysaccharide (LPS) is the key factor inducing mucosal and systemic inflammation in various intestinal and parenteral diseases, which could initially disrupt the epithelial barrier function. EphrinA1/ephA2 is speculated to increase the epithelial permeability for its “repulsive interaction” between adjacent cells. This study aim to investigate the role of ephrinA1/ephA2 in LPS-induced epithelial hyperpermeability.MethodsIn vivo model challenged with oral LPS in C57BL/6 mice and in vitro model exposed to LPS in Caco2 monolayer were established. The barrier function was assessed including expression of tight junction proteins (occludin and claudin-1), transepithelial electrical resistance, and permeability to macromolecules (fluorescein isothiocyanate-labeled fluorescent dextran 4 kDa [FD4]). Moreover, the expression and phosphorylation of ephrinA1/ephA2 were quantified, and its roles in the process of epithelial barrier disruption were confirmed via stimulating ephA2 with ephrinA1-Fc chimera (ephrinA1-Fc) and inactivating ephA2 with ephA2-Fc chimera (ephA2-Fc), or ephA2 monoclonal antibody (ephA2-mab), as well as inhibiting extracellular signal-regulated kinase 1/2 (ERK1/2) with PD98059.ResultsLPS induced significant barrier dysfunction with dismissed occludin and claudin-1 expression, reduced transepithelial electrical resistance and increased FD4 permeability, accompanied by upregulated ephrinA1/ephA2 pathway and phosphorylation of ephA2 receptor. Furthermore, ephA2-Fc, and ephA2-mab ameliorated LPS-induced epithelial hyperpermeability, which was also inhibited by PD98059. Additionally, ephrinA1-Fc led to apparent epithelial leakage in Caco2 monolayer by promoting the phosphorylation of ERK1/2, which could be obviously blocked by ephA2-mab and PD98059.ConclusionEphrinA1/ephA2 promotes epithelial hyperpermeability with an ERK1/2-dependent pathway, which involves in LPS-induced intestinal barrier dysfunction.

Nanoflake-Constructed Supramolecular Hierarchical Porous Microspheres for Fire-Safety and Highly Efficient Thermal Energy Storage.

The leakage and fire hazard of organic solid-liquid phase change material (PCM) tremendously limit its long-term and safe application in thermal energy storage and regulation. In this work, novel nanoflake-fabricated organic-inorganic supramolecular hierarchical microspheres denoted as BPL were synthesized through the electrostatically driven assembly of poly(ethylene ammonium phenylphosphamide) (BP) decorated layered double hydroxides using sodium dodecyl sulfate as a template. Then the BPL was simultaneously utilized as a porous supporting material and flame retardant for polyethylene glycol to fabricate shape-stabilized PCM (BS-PCM). Benefiting from the structural uniqueness of the BPL microsphere, the BS-PCM possessed a high latent heat capacity of 116.7 J g-1 and excellent thermoregulatory capability. Moreover, the BS-PCM had no apparent leakage after a 200-cycle heating/cooling process and showed excellent thermal reversibility, superior to similar solid-liquid PCMs reported in recent literature. More interestingly, unlike flammable PEG, BS-PCM showed excellent fire resistance when exposed to a fire source. The unique BPL porous microsphere provided not only a microcontainer with high storage capacity for solid-liquid PCM, but also a fire resistant barrier to PEG, supplying a promising solution for highly efficient and fire-safe thermal energy storage.

Numerical Experiments on Variation of Freshwater Plume and Leakage Effect From Mississippi River Diversion in the Lake Pontchartrain Estuary

AbstractA Finite Volume Community Ocean Model is used to investigate how wind impacts the circulation and evolution of a freshwater plume from Mississippi River diversion in the Lake Pontchartrain Estuary. Results show that northerly and southerly winds tend to stretch the plume in the east‐west directions, while easterly and westerly winds constrain the plume in the north‐south directions. Increasing wind magnitude tends to increase the total salt content of the estuary except under weak westerly wind (&lt;6 m/s) during which salt content decreases. A no‐motion middepth interface is found (by the model and verified by the data), separating the top layer downwind flow and bottom layer upwind flow. Increasing wind magnitude can enhance the two‐layered flows and lower the no‐motion plane between the two opposite flows. Apparent small leakage of the river water through the diversion structure prior to its opening is found to impact the vertical structure of flows and salinity: Mixing is facilitated by the large amount of freshwater leaked into the lake prior to the opening of the diversion; wind‐driven gyres are diminished; the average potential energy demand, a quantity used to measure the vertical stratification, is reduced to very low values; more deviation from the quasi‐steady state balance tends to occur; and a total of 3.7 × 108 kg of salt is reduced during the opening period of the Bonnet Carré Spillway. The Lake Pontchartrain Estuary is completely dominated by the river water within about 25 days, when salinity drops from an average value of 4 g/kg to essentially zero.

Protein loss in the small intestine detected by capsule endoscopy

A 32-year-old woman presented with leg edema and low serum albumin. Although she had experienced intermittent episodes of leg edema since childhood, she had not been examined for this condition. Laboratory data showed hypoproteinemia (3.8 g/dL) and hypoalbuminemia (1.8 g/dL). The result of serology for infectious enteropathy was negative. Gastroduodenoscopy and total colonoscopy showed no abnormal findings. The result of Sudan III staining of the stool was positive. A fecal α-1-antitrypsin clearance test showed abnormal leakage (128 mL/day), and double-balloon enteroscopy showed white villi, white nodules (A), and chylorrhea in the jejunum. Capsule endoscopy showed apparent leakage of white lymphatic fluid from the white villi, where the internal pressure must have been physiologic. It showed leakage of protein from the villi to the intestinal lumen (B). It may be difficult to see a spontaneous leak with double-balloon enteroscopy when the intraluminal pressure is high. Biopsy specimens from the jejunal mucosa demonstrated characteristic lymphangiectasia (C, H&E and D2-40, orig. mag. ×40; D, H&E and D2-40, orig. mag. ×40 D2-40) of the lamina propria. Albumin scintigraphy showed hot spots in the small intestine. These data confirmed a diagnosis of primary intestinal lymphangiectasia and showed that the hypoalbuminemia was secondary to protein-losing enteropathy. The patient was given a low-fat diet with medium-chain triglyceride supplementation, and her clinical condition improved. All authors disclosed no financial relationships. Commentary Primary intestinal lymphangiectasia with protein-losing enteropathy is a disorder wherein ectasia of the enteric lymphatics develops. This can occur at almost any layer of the GI lumen wall. This disorder is usually seen in young patients but can be seen in adults as well (as was the case with this patient). Intestinal lymphangiectasia can be seen in the context of other conditions, including Noonan syndrome, von Recklinghausen syndrome, and Turner syndrome, among others. This patient also had symptoms that suggested this condition had been present for many years. This case illustrates the value of a well-timed capsule endoscopy study, whereby a key finding was detected that allowed elucidation and/or confirmation of a diagnosis for the patient. The findings seen in this study could be intermittent or ongoing, so the capsule findings are both as striking as they are rare. Douglas G. Adler, MD, FASGE, GIE Senior Associate Editor, University of Utah School of Medicine, Salt Lake City, Utah Mohamed O. Othman, MD, Associate Editor for Focal Points

Intravital Vascular Phototheranostics and Real-Time Circulation Dynamics of Micro- and Nanosized Erythrocyte-Derived Carriers.

Erythrocyte-based carriers can serve as theranostic platforms for delivery of imaging and therapeutic payloads. Engineering these carriers at micro- or nanoscales makes them potentially useful for broad clinical applications ranging from vascular diseases to tumor theranostics. Longevity of these carriers in circulation is important in delivering a sufficient amount of their payloads to the target. We have investigated the circulation dynamics of micro (∼4.95 μm diameter) and nano (∼91 nm diameter) erythrocyte-derived carriers in real time using near-infrared fluorescence imaging, and evaluated the effectiveness of such carrier systems in mediating photothermolysis of cutaneous vasculature in mice. Fluorescence emission half-lives of micro- and nanosized carriers in response to a single intravenous injection were ∼49 and ∼15 min, respectively. A single injection of microsized carriers resulted in a 3-fold increase in signal-to-noise ratio that remained nearly persistent over 1 h of imaging time. Our results also suggest that a second injection of the carriers 7 days later can induce a transient inflammatory response, as manifested by the apparent leakage of the carriers into the perivascular tissue. The administration of the carriers into the mice vasculature reduced the threshold laser fluence to induce photothermolysis of blood vessels from >65 to 20 J/cm2. We discuss the importance of membrane physicochemical and mechanical characteristics in engineering erythrocyte-derived carriers and considerations for their clinical translation.

Is Circular Fibrin Sealing of Low Rectal Anastomosis Able to Prevent Leakage in 21-Day Follow-up? Randomized Experimental Trial in Pigs.

Purpose. Clinically apparent anastomotic leakage (AL) after low anterior rectal resection (LAR; <7 cm from anal verge) using circular double-stapled anastomosis without defunctioning stoma is up to 37.5%. However, it is unclear whether there is reduction of LAR after 21 postoperative days without defunctioning stoma but with extraluminal anastomotic application of fibrin sealant. Methods. Forty-eight-week-old pigs underwent LAR and circular double-stapled anastomosis in end-to-end technique (descendo-rectostomy). Animals were randomized into therapy and control group (cg). Therapy group (n = 20) received additional extraluminal circular anastomotic application of fibrin sealant. Objective was to assess incidence of clinically apparent and nonclinically apparent leakage through the 21st postoperative day. Remaining animals were sacrificed on the 21st day, and anastomotic region was analyzed. In case of earlier diagnosed AL, animals were sacrificed. Results. In cg, we observed clinically and nonclinically AL in 20% (n = 4). No animal was identified with a nonclinical-apparent leakage in this group, and all 4 animals with leakages presented clinical signs. In the therapy group, no animal (0/20) developed clinically apparent leakage signs. There were no leakages in this group, but 3 animals had ulcerative lesions without leak and without clinical signs. These lesions were observed intraluminally at crossing of staple lines after 21 days. In one of these animals, incomplete leakage was observed, blocked by fibrin sealant. Conclusion. In circular stapled colorectal anastomosis, circular fibrin glue sealant successfully protected anastomotic intraluminal wall defects at crossing of staple lines, reducing leakage rate from 20% to 0% (cg vs therapy group) after 21 postoperative days.

The STEM requirements of “Non-STEM” jobs: Evidence from UK online vacancy postings

Are employers in “non-STEM” occupations (e.g. Graphic Designers, Economists) interested in STEM (Science, Technology, Engineering, and Mathematics) graduates because of the knowledge and skills they acquired through their STEM education (e.g. “C++”, “Systems Engineering”) or simply because of their problem solving and analytical abilities? This is an important question in the UK where less than half of STEM graduates work in STEM occupations, and where this apparent leakage from the “STEM pipeline” is often considered as a wastage of resources. To address it, this paper goes beyond the discrete divide of occupations into STEM vs. non-STEM: using UK online vacancy postings, we measure STEM requirements at the level of jobs, by classifying each posting as either STEM or non-STEM based on its job description text instead of its occupation identifier. We find that 35% of all STEM jobs belong to non-STEM occupations, and that 15% of all vacancies posted in non-STEM occupations are in fact STEM jobs. Moreover, STEM jobs are associated with higher wages within both STEM and non-STEM occupations.

The Effects of Using Aluminum Oxide Nanoparticles as Heat Transfer Fillers on Morphology and Thermal Performances of Form-Stable Phase Change Fibrous Membranes Based on Capric⁻Palmitic⁻Stearic Acid Ternary Eutectic/Polyacrylonitrile Composite.

In this paper, innovative capric–palmitic–stearic acid ternary eutectic/polyacrylonitrile/aluminum oxide (CA–PA–SA/PAN/Al2O3) form-stable phase change composite fibrous membranes (PCCFMs) with different mass ratios of Al2O3 nanoparticles were prepared for thermal energy storage. The influences of Al2O3 nanoparticles on morphology and thermal performances of the form-stable PCCFMs were investigated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and measurement of melting and freezing times, respectively. The results showed that there was no apparent leakage trace from the SEM observation. The DSC analysis indicated that the addition of Al2O3 nanoparticles had no significant effect on phase transition temperatures and enthalpies of the CA–PA–SA/PAN/Al2O3 form-stable PCCFMs. The melting peak temperatures and melting enthalpies of form-stable PCCFMs were about 25 °C and 131–139 kJ/kg, respectively. The melting and freezing times of the CA–PA–SA/PAN/Al2O310 form-stable PCCFMs were shortened by approximately 21% and 23%, respectively, compared with those of the CA–PA–SA/PAN form-stable PCCFMs due to the addition of Al2O3 nanoparticles acting as heat transfer fillers.