bluuebunny/crossref_metadata_2025 huggingface dataset:
A new species of Leptolalax (Anura: Megophryidae) from Son Tra Peninsula, central Vietnam
Authors: NGUYEN LUAN THANH , POYARKOV NIKOLAY A. JR. , LE DZUNG TRUNG , VO BA DINH , PHAN HOA THI , DUONG TANG VAN , MURPHY ROBERT W. , NGUYEN SANG NGOC
Published: March 2018

Morphological, acoustic and molecular analyses result in the description of Leptolalax rowleyae sp. nov., a new species of frog in the Megophryidae, belonging to the L. applebyi Rowley & Cao species group from central Vietnam. It differs from its congeners by a combination of the following morphological attributes: (1) adult SVL 23.4–25.4 mm in males and 27–27.8 mm in females; (2) presence of distinct dark/brown dorsolateral markings, including black spots on flanks; (3) pinkish milk-white to light brown chest and belly with numerous white speckles; (4) tympanum distinct; (5) absence of webbing or lateral dermal fringes on fingers and toes; (6) pectoral glands comparatively small (3.3–4.7% of SVL); (7) ventrolateral glands indistinct; and (8) iris bicolored with copper tint in upper half fading to golden in lower third of iris. The male advertisement call of the new species consists of 4–6 notes, lacking a distinct introductory note, with an average dominant frequency of 3.2–3.5 kHz. The description of the tadpole constitutes the first description of larval morphology for a member of the L. appleybi species group. Genetically, an uncorrected sequence divergence of 7.4% for 16S rRNA separates the new species from its two closest relatives, L. ardens and L. melicus in the L. applebyi species group.
Morphology and molecular data reveal the presence of two new species under Rhamdia quelen (Quoy & Gaimard, 1824) (Siluriformes: Heptapteridae) species complex
Authors: ANGRIZANI RAFAEL C. , MALABARBA LUIZ R.
Published: March 2018

The eustatic movements triggered by glaciations during the Quaternary have shaped the landscape of Brazilian Atlantic Coast. Cyclic sea-level changes either isolated or connected freshwater fish populations, impacting their distribution and diversification. Rhamdia quelen has been widely recorded from the Brazilian Atlantic Coastal rivers, but it is also considered a species complex. A phylogeographic study carried out using three molecular markers of mtDNA and one of nDNA in the populations of Rhamdia from the hydrographic basins of Southern Atlantic Coast of Brazil recovered three evolutionarily distinct groups: one represented by the populations found in lowlands of all studied watersheds; the second group composed of populations found in the upper tributaries of the rio Araranguá, rio Mampituba and rio Tramandaí; and a third group found exclusively in the upper portions of rio Tubarão. The genetic divergences among these three lineages of Rhamdia is discussed according to sea level changes in the Quaternary. Two new species of Rhamdia are diagnosed and described based on morphological and molecular evidence.
Vocalizations, tadpole, and natural history of Crossodactylus werneri Pimenta, Cruz & Caramaschi, 2014 (Anura: Hylodidae), with comments on distribution and intraspecific variation
Authors: VIDIGAL IZADORA , DE CARVALHO THIAGO R. , CLEMENTE-CARVALHO RUTE B. G. , GIARETTA ARIOVALDO A.
Published: March 2018

Crossodactylus werneri was described based on specimens collected in the 1970’s at Parque Nacional do Itatiaia, being also reported for nearby localities. We collected specimens that we assigned to C. werneri, and recorded calls of the species during fieldworks at Serra das Cabras (Campinas, state of São Paulo). In this paper, we describe for the first time the vocalizations, tadpole, coloration in life, and comment on aspects of the natural history of C. werneri. Besides, the examination of specimens in zoological collections allowed us to extend the geographic range for this species. We also make remarks on morphological/chromatic variation and provide 16S rDNA sequences for the species. Adults were found along a slow-flowing streamlet with sandy/muddy bottom within a small fragment of secondary forest. Males called between sunset and first hours of the night. Advertisement call consisted of series of pulsed notes. Call duration lasted around 3 s, emitted at the highest rate of 17 calls per minute and six notes per second. Note duration lasted around 18 ms. Notes had poorly defined pulses (irregular and/or weak amplitude modulations along the note). The dominant frequency was about 3380 Hz. Territorial call had a long, well-defined pulsed portion followed by a higher-amplitude “squeak”. The dominant frequency was around 3400 Hz. Tadpoles were essentially similar to those of other Crossodactylus species, except by not having nostril ornamentation. Our record of C. werneri in Serra das Cabras might be regarded a rediscovery of this species since C. werneri had not been recorded for more than 30 years until our first record of C. werneri in the field from 2011 and subsequent years. Our record is approximately 100 km west, and Mococa 200 km northwest, from Santo Antônio do Pinhal, the westernmost previous record for C. werneri up to date. Gene sequences (16S rRNA) give insights into the genetic divergence between C. werneri and some congeners.
Levensteiniella manusensis sp. nov., a new polychaete species (Annelida: Polynoidae) from deep-sea hydrothermal vents in the Manus Back-Arc Basin, Western Pacific
Authors: WU XUWEN , XU KUIDONG
Published: March 2018

A new species belonging to the subfamily Macellicephalinae (Annelida: Polynoidae), Levensteiniella manusensis sp. nov., is described based on material collected from deep-sea hydrothermal vents in the Manus Back-Arc Basin. The new species is readily distinguished from the congeners by having two pairs of ventral papillae on segments 11 and 12, the first pair of which is distally dichotomous. Levensteiniella manusensis is also characterized by the combination of the notochaetae which are smooth or serrated on the curved side, and the elytra with micro- and macropapillae on the surface and thickened bulbous projections on the posterior border. Based on morphological comparisons of the main features, we provide two keys to six species of Levensteiniella described to date based on males and females respectively.
Three new species of Parapercis (Perciformes: Pinguipedidae) and first records of P. muronis (Tanaka, 1918) and P. rubromaculata Ho, Chang & Shao, 2012 from Australia
Authors: JOHNSON JEFFREY W. , WILMER JESSICA WORTHINGTON
Published: March 2018

Three new species of pinguipedid fishes from northern Australia are described based on specimens collected by deep water demersal trawling. Parapercis algrahami sp. nov. is recorded from off Dunk Island, Qld, south to Newcastle, NSW, in 67–333 m. It is distinct in having five narrow transverse dark bars across the upper body and a dark spot dorsally on the caudal-fin base, 6 canine teeth in outer row at front of lower jaw, palatines with 1–2 rows of teeth, and predorsal scales extending far forward on the nape to the posterior portion of the interorbital region. Parapercis imamurai sp. nov. is recorded from off Saumarez Reef, Qld, south to off Coffs Harbour, NSW, in 256–405 m. It is unique in having colouration that includes a broad dusky bar from lower margin of eye across the suborbital region and three broad dusky bands crossing the body between the middle of the soft dorsal-fin and the caudal-fin base, 10 canine teeth in outer row at front of lower jaw, and the fifth dorsal-fin spine longest. Parapercis pogonoskii sp. nov. is unique in having a combination of three reddish-brown vertical bars on the upper body between the anterior and posterior portions of the soft dorsal fin, the soft dorsal fin with two large dusky blotches and caudal-fin base with a dusky blotch in the upper corner, 8–10 canine teeth in outer row at front of lower jaw, fifth dorsal-fin spine longest, angle of subopercle with a single broad spine, and angle of preopercle with 4–5 large widely-separated spines. Comparison of the mitochondrial cytochrome c oxidase subunit 1 (CO 1) genetic marker utilised in DNA barcoding produced significant genetic divergences of at least 8.1% and 14.1% between P. algrahami sp. nov. and P. pogonoskii sp. nov. respectively and their closest sampled congeners.        The geographic range of Parapercis rubromaculata Ho, Chang & Shao, 2012 is extended from Taiwan to the southern hemisphere waters off Western Australia, based on specimens collected from Shark Bay, north to Ashmore Terrace, in depths of 56–107 m. A revised diagnosis for the species is presented, meristic, morphometric and DNA barcoding data for the two populations are compared, and a detailed description of the colouration of fresh and preserved specimens from Australia is provided. Previous records of Parapercis macrophthalma (Pietschmann, 1911) from Western Australia are established as misidentifications of Parapercis muronis (Tanaka, 1918) and the latter is thereby confirmed from the southern hemisphere and Australian waters for the first time. Comparative meristic, morphometric and DNA barcoding data is provided for populations of P. muronis from Japan, Philippines and Western Australia.
A description of Pseudechiniscus xiai sp. nov., with a key to genus Pseudechiniscus in China
Authors: WANG LIZHI , XUE JING , LI XIAOCHEN
Published: March 2018

The new species from the Liupan Mountains in China, Pseudechiniscus xiai sp. nov., differs from other Pseudechiniscus species by the following characters: absence of striae between dots which institute cuticular sculpture, projections absent on caudal margin of pseudosegmental plate, notches absent on caudal margin of terminal plate, dots on ventral side of body forms a reticular patched design. A diagnostic key to the Chinese Pseudechiniscus species is provided.
The Energetics and Magnitude of Hydrometeor Friction in Clouds
Authors: Igel Matthew R. , Igel Adele L.
Published: March 2018

As hydrometeors fall within or from a cloud, they reach a terminal velocity because of friction with the air through which they settle. This friction has previously been shown to result in significant vertically integrated dissipation of energy, but the nature and vertical profile of this dissipation warrant further investigation. Here, its energetic origin is discussed. It is confirmed explicitly that the dissipated energy originates from the conversion of hydrometeor potential energy during settling as suggested in an earlier study by Pauluis and Held. The magnitude of this heating is then analyzed in a cloud-resolving model simulation of tropical, aggregated convection. Maximum heating from hydrometeor friction reaches ~10 K h−1. The simulation is compared to one without hydrometeor frictional heating. For the case simulated, hydrometeor frictional heating results in a drier mean state, greater cloud cover, lessened convective mass flux, and a warmer atmosphere throughout much of the troposphere. It is suggested that the heating imparted to the atmosphere by dissipation allows the air to recover most of the energy previously expended in lofting hydrometeors.
The effect of Tehran metro rail system on residential property values: A comparative analysis between high-income and low-income neighbourhoods
Authors: Forouhar Amir , Hasankhani Mahnoosh
Published: March 2018

Estimating the effect of rail transit on residential property values has resulted in mixed findings. Some researchers report positive effects on property values while others are negative or insignificant. The current paper argues that the impact of rail transit on property values depends on contextual factors which can influence magnitude and direction of the impact and cause variation in the findings. Tehran’s Metro Rail System is chosen because the neighbourhoods served by the metro to the north side and south side of the city are dramatically different in terms of economic, social and physical circumstances. A comparative analysis of six of Tehran’s metro stations is conducted between the high-income neighbourhoods, which are located primarily on the city’s north side, and lower-income neighbourhoods on the south side to determine the effects of proximity to metro stations on residential property values. The paper uses a mixed-method sequential explanatory design based on a before-and-after estimation strategy, which includes trend analysis, difference-in-differences model and qualitative impact assessment methods. The results show that there are large increases in premiums for residential properties near the lower-income neighbourhoods, the south side parts of the Tehran Metro Rail System, while a negative treatment effect for residential properties lying close to the northern stations in the high-income neighbourhoods. The qualitative survey also suggests that the impact of metro station is affected by a number of contextual factors, including the need for public transportation, land-use planning and management, socio-cultural effect and possible nuisance effects.
Reg‐ent within the Learning Health System
Authors: Spector‐Bagdady Kayte , Shuman Andrew G.
Published: March 2018

Clinical data registries are perhaps one of the most powerful outcomes of electronic medical records, and their benefits are projected to redound to patients and clinicians across the nation. The American Academy of Otolaryngology—Head and Neck Surgery Foundation's Reg‐ent fits within the conceptual framework of a learning health system. Because the data within this system are deidentified, research informed consent is not legally required. But ethical concerns remain regarding whether and how to best notify, and whether to obtain consent from, patients whose data are included. Particularly because data corroborate that a substantial minority of survey respondents believe that consent should be obtained for each research protocol (even for deidentified research) and because data breaches are, unfortunately, a serious risk, we recommend that the American Academy of Otolaryngology—Head and Neck Surgery Foundation ensure best practices for patient engagement as it continues to build Reg‐ent.
“Don’t Bother Your Pretty Little Head”
Authors: Kahalon Rotem , Shnabel Nurit , Becker Julia C.
Published: March 2018

We examined whether appearance compliments, despite their flattery, undermine cognitive performance. In Study 1, women participants ( N = 88 Israeli university students) who wrote about past situations in which they had received appearance compliments (but not competence-related compliments) showed worse math performance than women in a control/no compliment condition—especially if they scored high on trait self-objectification (TSO). In Study 2, men and women participants ( nwomen = 73, nmen = 75 Israeli university students) received bogus occupational evaluation feedback, which did or did not include an appearance compliment. Although appearance compliments led to mood improvement among participants with high TSO, they also undermined math performance among both women and men. Because receiving appearance compliments is a common experience for women (whereas men are typically complimented for their competencies), our findings suggest that appearance compliments serve as a mechanism that might subtly perpetuate gender inequality. For the promotion of societal gender equality, it is important that the public is aware that appearance compliments, even if meant well, may create sexist environments. Online slides for instructors who want to use this article for teaching are available on PWQ's website at http://journals.sagepub.com/page/pwq/suppl/index
Electrocatalytic Glucose Sensor for Long-Term in vivo use
Authors: Lager W. , Von Lucadou I. , Nischik H. , Nowak T. , Preidel W. , Ruprecht L , Stanzel M.J. , Tegeder V.
Published: March 2018

A catheter shaped electrocatalytic glucose sensor for in vivo application has been developed to determine the glucose level in blood and control the insulin dosage in a closed loop system for diabetes therapy. The principle of measurement is based on the electrochemical oxidation of glucose at a membrane-covered platinum electrode. For various potential steps, the impedance obtained at two different frequencies is a function of the glucose concentration. A series of implantations in the vena cava of sheep demonstrated the potential feasibility of the sensor. It was possible to determine the glucose concentration in sheep for more than 130 days with tolerable deviations from glucose reference measurements. The mean error was 2.5 mmol/l. The catheter was explanted after 211 days and histological examination revealed a good biocompatibility of all materials used.
Failure of Neutrophils to Recover Their Ability to Produce Superoxide after Stunning by a Conventional, Acidic, Lactate-Based Peritoneal Dialysis Solution
Authors: Ing T.S. , Yu A.W. , Podila P.V. , Zhou F.Q. , Kun E.W. , Strippoli P. , Nawab Z.M.
Published: March 2018

Exposure of human neutrophils to conventional, acidic, lactate-based peritoneal dialysis solutions for 5 minutes results in a depression of superoxide generation. In spite of restoration of extracellular pH to 7.4, these stunned cells failed to recover their ability to generate the anion after a period of an hour.
Polymeric biomaterials: influence of phosphorylcholine polar groups on protein adsorption and complement activation
Authors: Yu J. , Lamba N.M.K. , Courtney J.M. , Whateley T.L. , Gaylor J.D.S. , Lowe G.D.O. , Ishihara K. , Nakabayashi N.
Published: March 2018

The introduction to polymeric biomaterials of phosphorylcholine polar groups represents an approach towards the development of materials with improved blood compatibility. In this respect, two biomaterials, one a copolymer of butyl methacrylate and 2-methacryloyloxyethylphosphorylcholine (MPC), (poly(BMA-co-MPC) and the other, MPC-grafted Cuprophan, were examined with respect to their influence on protein adsorption and complement activation. Protein adsorption was studied by measurement of the adsorption of radiolabelled single proteins (albumin and fibrinogen), while complement activation was measured using radioimmunoassay for C3a des Arg. The investigation demonstrated that the polymers containing phosphorylcholine polar groups can achieve a marked reduction in protein adsorption and complement activation and supports the utilization of phosphorylcholine polar groups as a means of improving the compatibility of biomaterials for blood-contacting applications.
A liquid-liquid blood-gas exchange for the treatment of acute respiratory failure: A new blood gas exchange using artificial blood as an oxygen carrier
Authors: Mizuno H. , Isobe J. , Matsunobe S. , Nakamura T. , Shimizu Y. , Hitomi S.
Published: March 2018

A new liquid-liquid blood gas exchange system was investigated using a veno-venous low flow extracorporeal circuit. A 2 m2 hollow fiber dialyzer served as the interface of the blood and oxygen carrier (a 38 percent FC-43, perfluorocarbon emulsion in a buffered electrolyte solution), which was continuously recycled through a bubble oxygenator. Experiments were performed on five mongrel dogs under general anesthesia. Upon the arrest of spontaneous ventilation, the dogs' lungs were inflated with 50% oxygen gas under a positive pressure of 10 cmH2O. After 10 min of apnea the dogs' PaO2 decreased to 37 ± 14 mmHg, and the extracorporeal circulation was started at 10 ml/min/kg b./w. At 15 min the PaO2 had risen to 80 ± 41 mmHg and at 30 min to 121 ± 17 mmHg. The oxygen transfer was 8.3 ± 2.3 ml/min. The extracorporeal circulation was continued 5h, when PaO2 reached 156 ± 90 mmHg, and PaCO2 148 ± 43 mmHg, then stopped. Fifteen minutes later, the PaO2 had returned to 32 ± 10 mmHg. These findings indicate that our blood gas exchange system can supply a sufficient amount of oxygen to the body under apnea with continuous positive airway pressure.
Effects of ketorolac tromethamine on erythropoietin levels in Sprague Dawley rats
Authors: Hoff K.K. , Zawada E.T. , Alavi F.K. , Leyse J.W. , Santella R.N.
Published: March 2018

Ketorolac tromethamine (KT) is a potent analgesic, most often used in its injectable form postoperatively. Similar to other nonsteroidal antiinflammatory drugs (NSAIDs), it inhibits prostaglandin (PG) synthesis. Prostaglandins have been shown to be involved in the regulation of renal function as well as erythropoietin (Ep) production. The intent of this study was to determine the effect of KT on plasma Ep levels in Sprague Dawley (SD) rats. Twenty rats received either 15 mg/kg/d or the KT vehicle IM for 5d. Blood samples (1 ml) were collected via tail vein each day of treatment. Plasma Ep levels were significantly higher in the KT rats than normal controls with the greatest difference occurring on d4 of treatment (70.1 ± 10.8 vs 30.9 ± 10.84 mU/ml, p < 0.01). This change in Ep corresponded with a significant reduction in hematocrit (KT, 29.5 ± 2.2 vs C, 40.8 ± 2.2%, p< 0.01). Presence of fecal blood was noted in the KT treated rats. A similar second experiment was designed to determine if blood loss was the cause of altered Ep production. In this experiment controls (HC) were bled via tail vein, to match the hematocrits of KT treated animals. Repeated administration of KT led to a steady reduction in hematocrit. When compared, hematocrit matched animals showed no difference in plasma Ep levels on all days of treatment (KT, 48.0 ± 4.9 vs HC, 44.6 ± 3.1 mU/ml, N.S.). In conclusion, repeated administration of KT showed no impairment of Ep production and release in response to reduced hematocrit, suggesting that in this instance, prostaglandin inhibition plays a minimal role in Ep production or release.
Amino acid metabolism by hepatocytes in a hybrid liver support bioreactor
Authors: Fuchs M. , Gerlach J. , Encke J. , Unger J. , Smith M. , Neuhaus P. , Riedel E.
Published: March 2018

The amino acid patterns of medium perfusate in a liver cell bioreactor developed for a hybrid liver support system have been measured. There were considerable changes in the concentrations of glutamic acid, glutamine, alanine, arginine, ornithine and branched chain amino acids during the first 10 days which is indicative of dynamic cellular metabolism. From day 15, steady state conditions of nitrogen metabolism are reflected by stable amino acid turnover. Monitoring of urea, K+, and P-450 activity suggests that hepatocytes have switched to a stable protein synthesis with a general amino acid uptake and keto acid release following cell volume increase
Markers of Hepatitis C Infection among Hemodialysis Patients with Acute and Chronic Infection: Implications for Infection Control Strategies in Hemodialysis Units
Authors: Oliva J.A. , Ercilla G. , Mallafre J.M. , Bruguera M. , Carrió J. , Pereira B.J.
Published: March 2018

To evaluate strategies for screening patients on hemodialysis (HD) for markers of acute and chronic hepatitis C virus (HCV) infection, we studied sixty-nine patients at a single center over a 36-month period. Serum samples were tested for alanine aminotransferase (ALT) levels, anti-HCV and HCV RNA at 3–4 month intervals. Anti-HCV was tested for by EIA1, EIA2, and RIBA2. HCV RNA was detected by polymerase chain reaction (PCR). In addition, IgM antibody to the c33 antigen of HCV was detected by an experimental EIA. Of the 43 HD patients at the start of the study, anti-HCV was detected by EIA1 in 13 (30%). All EIA1 positive patients and 14 (47%) of the 30 EIA1 negative patients tested positive by EIA2. Thus, at the start of the study 27 (63%) of 43 patients tested positive for anti-HCV by EIA2. The presence of anti-HCV among EIA2 positive patients was confirmed by RIBA2 in all patients. Based on the PCR results, the sensitivity, specificity, positive predictive value and negative predictive value for EIA1 were 48%, 100%, 53% and 100%, respectively, and for EIA2 were 100%, 100%, 100% and 100%, respectively. During follow-up, 26 EIA2 negative patients began HD in the unit. Of the 42 EIA2 negative patients, five (12%) seroconverted for anti-HCV during follow-up. All five patients with new HCV infection tested positive for HCV RNA three months prior to the detection of anti-HCV by EIA2. In addition, IgM to c33 was detected three months prior to seroconversion for anti-HCV by conventional tests in the two patients in whom testing was performed. All patients in whom HCV RNA was detected remained HCV RNA positive through the course of the study. The HCV subtype testing revealed that 25 (86%) of 29 patients had HCV type II infection and the remainder had mixed infection with both type I and II. The results of this study demonstrate that EIA2 is a reliable predictor of HCV infection among HD patients, and that RIBA2 or PCR testing is not necessary in routine clinical practice. Further, clearance of viremia and recovery from HCV infection is unusual, and hence regular testing for HCV should be limited to patients who are EIA2 negative. Serum ALT levels and conventional anti-HCV tests are poor predictors of early HCV infection. The anti-c33 IgM test may have a role in the identification of individuals with early HCV infection.
Biological and Synthetic Conduits in Peripheral Nerve Repair: A Comparative Experimental Study
Authors: Giardino R. , Nicolialdini N. , Perego G. , Cella G. , Maltarello M.C. , Fini M. , Rocca M. , Giavaresi G.
Published: March 2018

Two different types of conduits, one biological, obtained with homologous glutaraldehyde preserved vein segments and the other synthetic bioabsorbable, made with Poly [L-lactide-co-6-caprolactone], were evaluated as guides for nerve repair in alternative to autologous grafts in an experimental animal model. Under general anesthetic, the ischiatic nerve of a number Wistar rats was transected to create a 1 cm gap, which was then repaired by means of the conduits or autologous grafts. Controls were performed at 1, 3 and 6 months; nerve regeneration was effective with both conduits, but the count of myelinated axons showed a significant difference between the synthetic and biological tubes (p<0.001). The Poly [L-lactide-co-6-caprolactone] guide was still intact 30 days after implant; progressive signs of degradation were present at 90 and 180 days. These results show that the synthetic conduits are better than those obtained with preserved vein segments and might be considered in alternative to autologous grafts in peripheral nerve reconstruction
Thermal Balance and Dialysis Hypotension
Authors: Maggiore Q. , Dattolo P. , Piacenti M. , Morales M.A. , Pelosi G. , Pizzarelli F. , Cerrai T.
Published: March 2018

Many Studies Have Confirmed Our Original Observation That Dialysate T Set At About 35° C Affords A Better Hemodynamic Protection Than The Standard Dialysate T Of 37-38° C. In This Review We Present Some New Data On The Hemodynamic Mechanism Of The Protective Effect Of Cold Dialysis On Blood Pressure. The Study Was Based On Serial Assessment Of The Percent Changes Occurring During Dialysis Treatment In Estimated Stroke Volume (Aortic Blood Flow Determined By Doppler Echocardiography), Blood Volume (Hemoglobinometry), Arterial Pressure (Dynamap), And Heart Rate (Ecg), From Which Cardiac Output (Co) Indexes And Total Peripheral Vascular Resistances (Tpvr) Were Derived. Of The 14 Pts Studied, 7 Showed A Drop In Mean Arterial Pressure (Map) Of 25° Or Greater During Standard Dialysis (Unstable Patients). Compared With The 7 Patients Having More Stable Intradialysis Map, Unstable Pts Showed Greater Reduction In Co Which Was Disproportionately Greater Than The Reduction In Blood Volume, And A Paradoxical Decrease In Tpvr, The Difference Being Highly Significant (P ≤ 0.01 For Both Changes). When Crossed-Over To Cold Dialysis, Along With A Significantly Lower Reduction In Map (P ≤ 0.01) The Unstable Pts Showed A Lower Decrease In Co Which Paralleled The Reduction In Blood Volume, And An Increase In Tpvr. These Changes Were Highly Significant (P ≤ 0.01). Data Suggest That Dialysis Hypotension Is Characterized By An Impaired Venous Return, Probably Due To The Peripheral Blood Pooling (Increased Ratio Between The ‘Unstressed’ And ‘Stressed’ Blood Volume) Associated With The Decrease In Tpvr. Exposure Of Extracorporeal Blood To Cold Dialysate Favours The Venous Return To The Heart By Increasing Tpvr And The ‘Stressed’ Blood Volume.
Control and Treatment of Hemostasis in Cardiovascular Surgery.
Authors: Szefner J.
Published: March 2018

The hemostasis protocol applied at the Cardiovascular Surgery Dept. of La Pitié Hospital has greatly reduced thromboembolic accidents and excessive bleeding, with consequent benefits for patients as well as cost reduction. Protocol also has been adopted for patients implanted with a circulatory assist device or a TAH. This paper presents our criteria on supervision and treatment of coagulation with such patients, who reflect all the acquired pathology in clinical hemostasis. From 04/86 to 07/94, 82 patients underwent TAH as a bridge to transplantation. Mean age: 38. Overall duration of mechanical support: 1930 days (mean: 23), of which 137 and 603 for 2 patients. Average duration of CPB: 150 min. Systematic approach to complex TAH-blood interaction and pre-operative multiple organ dysfunction used to control bleeding and/or thromboembolism after CPB. In addition to routine tests, specific regular testing was carried out at least once a day for platelet functions, for thrombin formation and its regulatory pathways, and for the fibrinolytic system. Patients were treated with small doses of Heparin, large doses of Dypyridamole, small doses of Aspirin, modulated doses of Aprotinin, Ticlopidine, Pentoxifylline, FFP, as well as Fibrinogen and AT III concentrates. Dosage was adapted to patient's clinical profile as well as to test interpretation criteria to provide personalized treatment. DIC, widely present in its different phases, was thus diagnosed and treated. All DIC bleeding was controlled, making it possible to detect other causes of post-operatory bleeding and use blood derivates rationally. There were no thromboembolic complications and no iatrogenic bleeding. TAH explantation shows no evidence of macroscopic clots in high risk sites, confirmed by microscopic analysis.
Bioimpedance Analysis (BIA) in Hemodialysis: Technical Aspects
Authors: Talluri A. , Maggia G.
Published: March 2018

Phase-sensitive impedance analysis in association with anthropometric parameters provides adequate body composition estimates in nephropathic subjects, with complex three-compartment modelling as a reference. Extracellular fluid shifts can be detected during ultrafiltration by phase sensitive impedance analyzers. Rough impedance parameters such as Reactance and Phase Angle have been normalized with large series of data collected from reference populations and a bioeletric nomogram, termed Biagram®, is proposed to assess the normality between Extracellular and Intracellular spaces, without the need of anthropometric parameters such as Height and Weight.
Prerenal Azotemia: Differentiation of Hyperureagenesis from Renal Hypoperfusion Using Urinary Urea Nitrogen Data
Authors: Sklar A.H. , Riesenberg L.A. , UR Rehman A. , Smith S. , Rivera-Padilla H.
Published: March 2018

Blood urea nitrogen (BUN) rises disproportionately to serum creatinine in patients with prerenal azotemia whether due to impaired hemodynamics or excessive ureagenesis. To determine whether urinary urea nitrogen excretion rates can distinguish between these causes of hyperuremia we performed a cross-sectional observational study to compare urinary urea nitrogen excretion rates in a highly selected group of patients with prerenal azotemia. Patients who had stable serum creatinine levels, BUN: serum creatinine ratios exceeding 20:1, and progressive azotemia were identified from the hospital laboratory data base. Using conventional clinicolaboratory criteria, 27 patients were diagnosed with either renal hypoperfusion (group I; n = 17) or hyperureagenesis ((group II; n = 10). Random urine sampling for electrolytes, osmolality, creatinine, and urea nitrogen was followed by 24 h collection for creatinine clearance and urinary urea nitrogen. There were no significant differences in age, gender, absolute levels of BUN, or BUN: serum creatinine ratios between the groups. Creatinine clearance (ml/min/1.73 m2) (ml/s/1.73 m2) was lower in group I than in group II (21 ± 16 vs. 36 ± 13; p<0.05) (0.35 ± 0.27 vs. 0.60 ± 0.22; p < 0.05). Twenty-four hour urinary urea nitrogen levels were significantly different (group I, 4.8 ± 2.9 vs. group II, 13.6 ± 3.2 gm; p < 0.001) (group I, 171 ± 300 vs. group II, 486 ± 114 mmol; p < 0.001). Random urine urea excretion indices were less discriminating but nevertheless still capable of separating the groups. Timed as well as random urine urea nitrogen determinations may assist in differentiating prerenal azotemia due to renal hypoperfusion from hyperureagenesis. Differentiation of these causes of prerenal azotemia might prevent iatrogenic overhydration of patients with azotemia incorrectly attributed to hemodynamic disturbances.
Removal of constitutive and inducible nitric oxide synthase-active compounds in a modified hemodiafiltration with on-line production of substitution fluid: the contribution of convection and diffusion
Authors: Arese M. , Cristol J.P. , Bosc J.Y. , Bussolino F. , Wratten M.L. , Tetta C. , Strasly M. , Canaud B.
Published: March 2018

Chronic renal failure and the uremic state lead to accumulation of various endogenous inhibitors of nitric oxide synthase. Previous studies on end-stage uremic patients nitric oxide synthase activity in murine vascular endothelium and cytokine-induced macrophage cell lines was shown to be modulated during treatment (Nephrol Dial Transplant 1995; 10: 1386-96). Paired filtration dialysis, a modified hemodiafiltration technique, physically separates convection from diffusion. Plasmas, ultrafiltrates and dialysates from seven uremic patients undergoing paired filtration dialysis performed using ultrapure apyrogen substitution fluid in the absence (first 120 min) or presence (last 120 min) of extracellular fluid reduction were tested for their inhibitory/stimulatory effect on ecNOS, constitutively expressed on t. End 1 cell line, a murine vascular endothelium, or for their inducing effect on iNOS, inducible on J774 cells, a macrophage cell line. On ecNOS, Group 1 (stimulatory, 3/7 patients) markedly enhanced the ecNOS activity as compared to control plasma, whereas group 2 plasma (inhibitory, 4/7 patients) inhibited ecNOS plasma. Post-dialysis plasma samples from all Group 1 and 2 patients showed a marked decrease of the predialysis stimulatory and inhibitory activity, respectively. On iNOS: all patient plasmas stimulated iNOS activity. The UF and particularly the dialysate had a remarkable iNOS inducing effect (Group 1). The substitution fluid obtained at 120 min during treatment in Group 1 and 2 had no effect on NOS activity. No correlation was found between predialysis ecNOS or iNOS activity values with mean systolic or diastolic pressures. These studies suggest a complex balance of ecNOS inhibitors/stimulators and iNOS inducers in uremia. Dialysis may remove ecNOS inhibitors and stimulators by convection and, in the latter case, by diffusion. iNOS inducers are removed during dialysis, suggesting the biocompatibility of the dialysis system with the on-line production of ultrapure substitution fluid.
Long Term Evaluation of Gas Exchange and Hydrodynamic Performance of a Heparinized Artificial Lung: Comparison of Two Different Hollow Fiber Pore Sizes
Authors: Crotti S. , Tubiolo D. , Pelosi P. , Chiumello D. , Mascheroni D. , Gattinoni L.
Published: March 2018

We compared the performance of a heparinized hollow fiber artificial lung (Medtronic, Minimax) featuring standard hollow fibers (Group A) and experimental hollow fibers with a smaller pore size (Group B). Four sheep in each group underwent a veno-venous bypass for 72 hours. Every 6 hours, at 3 different blood flow rates (BFr) (400, 800, 1200 ml/min), at a constant gas flow rate (Gfr = 4 L/min), and at a constant blood inlet PCO2 (45-55 mmHg), we measured the oxygenation performance (O2 transfer = VO2 and blood outlet PO2 = PO2out), CO2 removal (CO2 transfer = VCO2 and PCO2 outlet = PCO2out) and pressure drop across the device (ΔP). A total of about 50 measurement sets were obtained for each group at different time points and blood flow rates. Both groups showed a good oxygenation performance (PO2out always higher than 200 mmHg) and no differences were observed between the two groups (at 1200 ml/min BFr, the average VO2 of all time points was 47 ± 15 ml/min in group A and 44 ± 11 ml/min in group B, mean ± SD, NS). During the first 24 hours, the VCO2 was higher in Group B than in Group A at each BFr (at 1200 ml/min BFr, 81 ± 18 vs 67 ± 20 ml/min, p<0.01), while no differences were observed during the subsequent 48 hours. Throughout the entire experiment, VCO2 increased with increasing BFr in both groups, (in group B, from 43 ± 14 ml/min at 400 ml/min BFr, to 73 ± 17 ml/min at 1200 ml/min BFr, average of all time points, p<0.01). In both groups the ΔP increased with the increasing BFr, but it was lower in Group B than in Group A at BFr 800 and 1200 ml/min (at 1200 ml/min BFr, 51 ± 15 mmHg vs 65 ± 17 mmHg, p<0.01), and remained stable for the entire experimental period.
Global and Extended Coagulation Monitoring during Extracorporeal Lung Assist with Heparin-Coated Systems in ARDS Patients
Authors: Gerlach M. , Föhre B. , Keh D. , Riess H. , Falke K.J. , Gerlach H.
Published: March 2018

Heparin-coated systems for extracorporeal lung-assist (ECLA) were developed to reduce hemorrhagic risk by lowering the systemic heparinization, monitored by global tests, e.g. activated coagulation time (ACT) and activated partial thromboplastin time (APTT). Since this strategy gives no insight into procoagulant states, five ARDS patients receiving ECLA with heparin-coated systems were investivated for changes in coagulation using both global and extended tests. During ECLA onset the APTT and ACT were within or near normal ranges, platelets decreased 76.5% within 48h, fibrinogen decreased 28.7%, thrombin-antithrombin-III complexes were elevated before ECLA (53 μg/L), but demonstrated an additional peak (238 μg/L), plasminogen-activator-inhibitor-1 increased 12-fold, and the C1-inhibitor dropped 14.1%. In conclusion, after the onset of ECLA from a previous prethrombotic state, the precoagulant, anticoagulant, fibrinolytic and complement systems were activated in a similar way to that reported for non-heparinized systems with high-dose heparin. This was however only monitored by an extended test panel which was unable to predict thromboembolic events during ECLA.
On-Line Hemodiafiltration with Pre- and Postdilution: A Comparison of Efficacy
Authors: Ahrenholz P. , Winkler R.E. , Ramlow W. , Tiess M. , Müller W.
Published: March 2018

Since the introduction of on-line substituate preparation, high substituate rates (Qs) in pre- and postdilution for hemodiafiltration (HDF) procedures can be realized. During postdilution HDF (POD-HDF) and additional convective removal is possible, but in vivo Qs is limited to approx. 1/3Qb (bloodflow). With predilution HDF (PRD-HDF) higher Qs and therefore high convective transport rates by ultrafiltration can be reached. On the other hand the blood concentration is diminished by predilution. Further decrease of the diffusive transport is caused by reduced dialysate flow Qd due to separation of the substituate from the dialysate (Fresenius 4008 On-Line HDF, Gambro AK100 Ultra). The theoretical description of the combined diffusive-convective transport is limited to 1-dimensional models and small UF-rates. Therefore for practical and theoretical purposes the assessment of the efficacy of on-line PRD-HDF and POD-HDF in different molecular weight ranges is desirable. By means of in vitro experiments the effective clearances Keff of hemodialysis (HD, dialyzer: Fresenius F60) for urea, creatinine, vitamin B12 and inulin were compared with measured and theoretical Keff of POD- and PRD-HDF. The theoretical expectation is confirmed that Keff for small molecular weight substances decreases slightly with PRD-HDF and increases for larger molecules. In the case of POD-HDF Keff for small molecular weight substances increases slightly and strongly for larger molecules. In vivo experiments were performed to measure the real substance removal from patient's blood and to figure out the impact of dialysate flow (collection of the used dialysate during the 1. treatment hour and concentration measurements for urea, creatinine, phosphate, ß2-MG). The results show that the substraction of Qs from Qd reduces Keff for urea, creatinine and phosphate but not for ß2-MG. PRD-HDF with Qd = 500 ml/min is significantly less effective for small molecules than HD. There is no significant difference of Keff for urea, creatinine, phosphate during HD and PRD-HDF with Qd = 800 ml/min, but a significant increase of 10-15% for POD-HDF Keff for ß2-MG increases by 75% for PRD-HDF and 95% for POD-HDF compared with HD (Qd = 500 ml/min).
Computational Analysis of Blood Volume Dynamics during Hemodialysis
Authors: Lopot F. , Kotyk P.
Published: March 2018

The recently introduced continuous blood volume monitoring (CBVM) technique enables real time observation of the blood volume (BV) response to ultrafiltration. This response differs quite widely among patients even under otherwise comparable conditions. Assessing the clinical recordings of over 100 CBVM measurements, identification of a static and a dynamic component of the overall BV reduction was made. Computational analysis of the factors that influence BV response variability was then performed by means of a three-pool model of sodium, potassium, and urea kinetics with the following results. The blood volume profile contains clinically highly interesting yet cummulative information. Except for the small change and flat BV profiles the static component is predominant. From the external factors, the static component of BV reduction during hemodialysis is influenced by the total ultrafiltered volume and by the degree of overhydration. From the patient's internal factors, compliance of his cardiovascular system is dominant. BV is also more reduced in patients with lower values of total plasma protein content and/or lower hematocrit. The BV reduction dynamic component is primarily influenced by the applied ultrafiltration rate. A certain influence is also exerted by the ultrafiltration coefficient of the capillary wall which may vary in different individuals.
Qualitative Assessment of Blood Washing with the Continuous Autologous Transfusion System (CATS)
Authors: Walpoth B.H. , Eggensperger N. , Walpoth-Aslan B.N. , Neidhart P. , Lanz M. , Zehnder R. , Spaeth P.J. , Kurt G. , Althaus U.
Published: March 2018

A number of different blood-processing methods can be used at the end of cardiopulmonary bypass (CPB) to improve the quality of autologous blood. They include centrifugation, hemofiltration and cell-washing. They differ in processing time required, cost of disposables and the quality of the processed autologous blood product. The newly developed continuous auto-transfusion system (CATS: Fresenius AG, Bad Homburg) uses a continuous cell-washing method. In a prospective study, the oxygenator blood of 10 patients was processed at the end of cardiac surgery with CATS and the quality of autologous blood before and after processing was compared. The processing volumes and the time required were recorded. The concentrations and elimination rates of blood parameters and waste products such as activated coagulation and complement products were measured. At the end of CPB a mean volume of 1,010 ± 174 ml diluted oxygenator blood was processed and concentrated to 310 ± 88 ml in 11.0 ± 2.2 mins. Cellular elements such as erythrocytes and leucocytes were mostly retained and their concentration showed a significant increase after processing (250% and 210% respectively; p < 0.01). Thus, the blood processing with CATS resulted in an excellent hemoconcentration (hematocrit 62 ± 3 vs. 24 ± 4% before processing) with a consistent reproducibility. On the other hand, the CATS concentrate showed a significant loss of autologous plasma proteins. Likewise, all water soluble elements such as waste products are significantly lower in concentration after processing and, if calculated by quantity, they show a high elimination rate (> 93%).

In conclusion, the continuous autologous transfusion system permits an automated, rapid and continuous processing of autologous blood yielding a standardised high quality erythrocyte concentrate.
Stroke Volume Validation and Energy Evaluation for the Dynamic Training of Skeletal Muscle Ventricles
Authors: Klapproth P. , Guldner N.W. , Sievers H.H.
Published: March 2018

Skeletal muscle ventricles used for cardiac assistance were trained dynamically by shifting volume within an elastic training device. To optimize this dynamic training that is by variation of stimulation patterns and application of drugs, methods for stroke volume and energy evaluation were required.

A volume shift induced by a muscle contraction resulted in a pressure rise in the training device. Stroke volume was calculated by relating the pressure difference of a muscle contraction to the device's compliance. For validation of the calculated stroke volume, a mock system was built to simulate muscle contractions under various conditions. The stroke volume measured independently and calculated by means of the pressure rise inside the training device, showed an approximately one-to-one relation (R=0.996). Calculation of delivered energy from skeletal muscle ventricles thereby became possible.

This method offers a simple, reliable and practical procedure to quantify the dynamic training of skeletal muscle ventricles for use in cardiac assistance.
Fatigue damage analysis of fiber-reinforced polymer composites—A review
Authors: Ansari Md. Touhid Alam , Singh Kalyan Kumar , Azam Mohammad Sikandar
Published: March 2018

Fiber-reinforced polymer composites are becoming suitable and substantial materials in the repair and replacement of conventional metallic materials because of their high strength and stiffness. These composites undergo various types of static and fatigue loads during service. One of the major tests that conventional and composite materials have to experience is fatigue test. It refers to the testing for the cyclic behavior of materials. Composite materials are different from metals, as they indicate a distinct behavior under fatigue loading. The fatigue damage and failure mechanisms are more intricate in composite materials than in metals in which a crack initiates and propagates up to fracture. In composite materials, several micro-cracks initiate at the primary stage of the fatigue growth, resulting in the initiation of various types of fatigue damage. Fiber volume fraction is an important parameter to describe a composite laminate. The fatigue strength increases with the increase of the fiber volume fraction to a certain level and then decreases because of the lack of enough resin to grip the fibers. The fatigue behavior of fiber-reinforced polymer composites depends on various factors, e.g., constituent materials, manufacturing process, hysteresis heating, fiber orientation, type of loading, interface properties, frequency, mean stress, environment. This review paper explores the effects of various parameters like fiber type, fiber orientation, fiber volume fraction, etc. on the fatigue behavior of fiber-reinforced polymer composites.