Unexpected catalytic activity of nanorippled graphene.

Graphite is one of the most chemically inert materials. Its elementary constituent, monolayer graphene, is generally expected to inherit most of the parent material's properties including chemical inertness. Here, we show that, unlike graphite, defect-free monolayer graphene exhibits a strong activity with respect to splitting molecular hydrogen, which is comparable to that of metallic and other known catalysts for this reaction. We attribute the unexpected catalytic activity to surface corrugations (nanoscale ripples), a conclusion supported by theory. Nanoripples are likely to play a role in other chemical reactions involving graphene and, because nanorippling is inherent to atomically thin crystals, can be important for two-dimensional (2D) materials in general.

Demonstration of the effect of stirring on nucleation from experiments on the International Space Station using the ISS-EML facility.

The effect of fluid flow on crystal nucleation in supercooled liquids is not well understood. The variable density and temperature gradients in the liquid make it difficult to study this under terrestrial gravity conditions. Nucleation experiments were therefore made in a microgravity environment using the Electromagnetic Levitation Facility on the International Space Station on a bulk glass-forming Zr57Cu15.4Ni12.6Al10Nb5 (Vit106), as well as Cu50Zr50 and the quasicrystal-forming Ti39.5Zr39.5Ni21 liquids. The maximum supercooling temperatures for each alloy were measured as a function of controlled stirring by applying various combinations of radio-frequency positioner and heater voltages to the water-cooled copper coils. The flow patterns were simulated from the known parameters for the coil and the levitated samples. The maximum nucleation temperatures increased systematically with increased fluid flow in the liquids for Vit106, but stayed nearly unchanged for the other two. These results are consistent with the predictions from the Coupled-Flux model for nucleation.

Pursing a career in academic surgery among African American medical students.

BACKGROUND: There are few African American students in medical school, and even fewer are choosing academic surgical careers. The objective of this study is to provide insight into what barriers URM students perceive when considering a career in academic surgery. METHODS: This qualitative, descriptive study was conducted at the University of Pennsylvania. Sixteen African American students with an interest in surgery were recruited to participate in the study. The outcomes reported are themes of how participants perceive the challenges of pursuing an academic surgical career. RESULTS: Barriers to pursuing a career in academic surgery cited by students included lifestyle concerns, financial pressures, having to work in a predominantly white environment, lack of mentorship, feelings of having to prove oneself, stressful environments and concerns of being a minority female in surgery. CONCLUSIONS: These study findings indicate that the persistent dearth of African-Americans in academic surgery is likely multi-factorial. Some ways surgical leadership can begin addressing these issues is through establishment of formal mentorship programs, ensuring non-discriminatory recruiting processes, having explicit goals of improving diversity and supporting pipeline programs.

Resistivity Saturation in Metallic Liquids Above a Dynamical Crossover Temperature Observed in Measurements Aboard the International Space Station.

Although a resistivity saturation (minimum conductivity) is often observed in disordered metallic solids, such phenomena in the corresponding liquids are not known. Here we report a saturation of the electrical resistivity in Zr_{64}Ni_{36} and Cu_{50}Zr_{50} liquids above a dynamical crossover temperature for the viscosity (T_{A}). The measurements were made for the levitated liquids under the microgravity conditions of the International Space Station. Based on recent molecular dynamics simulations, the saturation is likely due to the ineffectiveness of electron-phonon scattering above T_{A} when the phonon lifetime becomes too short compared to the electron relaxation time. This is different from the conventional resistivity saturation mechanisms in solids.

Maximum supercooling studies in Ti39.5Zr39.5Ni21, Ti40Zr30Ni30, and Zr80Pt20 liquids-Connecting liquid structure and the nucleation barrier.

Almost three quarters of a century ago, Charles Frank proposed that the deep supercooling observed in metallic liquids is due to icosahedral short-range order (ISRO), which is incompatible with the long-range order of crystal phases. Some evidence in support of this hypothesis had been published previously. However, those studies were based on a small population of maximum supercooling measurements before the onset of crystallization. Here, the results of a systematic statistical study of several hundred maximum supercooling measurements on Ti39.5Zr39.5Ni21, Ti40Zr30Ni30, and Zr80Pt20 liquids are presented. Previous X-Ray and neutron scattering studies have shown that the structures of these liquid alloys contain significant amounts of ISRO. The results presented here show a small work of critical cluster formation (W* = 31-40 kBT) from the analysis of the supercooling data for the Ti39.5Zr39.5Ni21 liquid, which crystallizes to a metastable icosahedral quasicrystal. A much larger value (W* = 54-79 kBT and W* = 60-99 kBT) was obtained for the Ti40Zr30Ni30 and Zr80Pt20 liquids, respectively, which do not crystallize to an icosahedral quasicrystal. Taken together, these results significantly strengthen the validity of Frank's hypothesis.

Surgical solutions for refractory J-pouch inlet obstruction.

AIM: Many surgeons consider total proctectomy with ileal pouch-anal anastomosis as the treatment of choice for patients with medically refractory ulcerative colitis or ulcerative colitis with dysplasia. However, obstruction occurring at the pouch inlet or involving the afferent limb can be refractory to nonoperative or endoscopic management. Historically, these refractory obstructions have usually required resection of the pouch. There is now increasing evidence to suggest that pouch salvage surgery may be feasible in these patients. METHODS: A retrospective review was performed of all patients of a single surgical practice who underwent a neo ileal-pouch anastomosis for J-pouch inlet obstructions between 2000 and 2017. Data collected included patient demographics, preoperative workup, intra-operative findings, type of surgical intervention and postoperative outcomes. RESULTS: Surgical interventions were performed on eight patients with J-pouch inlet obstructions. Six patients had inlet strictures or acute angulations at the inlet, which were either bypassed or resected and primarily anastomosed. Two patients had internal hernias posterior to the mesentery, with volvulus of the pouch. At a mean follow-up of 36.5 months, all patients retained their pouches and the mean number of daily bowel movements was eight. Two major and two minor complications occurred. DISCUSSION: J-pouch inlet obstructions may take years to develop. In patients with obstruction who are refractory to endoscopic or medical treatment, good functional results may be obtained with pouch salvage procedures. With increasing numbers of J-pouches being performed, awareness of novel surgical techniques is important.

[Risk factors associated with the development of enterocolitis in Hirschsprung's disease]. / Factores de riesgo asociados al desarrollo de enterocolitis en la enfermedad de Hirschsprung.

OBJECTIVES: Hirschsprung's-associated enterocolitis (HAEC) is a live-threatening complication that remains badly understood. Our objective is to identify the risk factors related to the development of HAEC in the cohort of patients with Hirschsprung's disease (HD) treated in our center. METHODS: We reviewed the patients treated for HD between 2000 and 2016. Ninety four patients were included, and the clinical details related to the disease were evaluated. Our primary outcome measure was the development of HAEC. Relative risks are presented with 95% confidence intervals. RESULTS: Twenty seven patients out of the ninety four (28.7%) suffered HAEC. None of them died from this complication. The extended aganglionosis, the need of a preoperative stoma, a transabdominal surgery and the diagnosis before the age of 7.2 months were related to a higher risk of suffering HAEC. CONCLUSIONS: HAEC remains a common complication in patients suffering from HD, especially those with complex forms. The identification of the risk factors could result in a better control of the HAEC, which lead to a faster diagnosis and treatment, reducing the morbi-mortality related to HAEC.

OBJETIVO: La enterocolitis (EC) asociada a la enfermedad de Hirschsprung (EdH) es una entidad de etiopatogenia desconocida y potencialmente mortal. Nuestro objetivo es identificar los factores implicados en el desarrollo de EC en una cohorte de pacientes con EdH tratados en el nuestro centro. METODOS: Se revisaron los pacientes tratados por EdH en el periodo 2000-2016. Se incluyeron 94 pacientes, recogiendo de las historias clínicas variables demográficas y todas las relacionadas con la enfermedad. Se realizó un estudio de riesgo uni y multivariado usando como variable dependiente la existencia de un cuadro de enterocolitis. Los resultados se presentan con riesgo relativo (RR) con su intervalo de confianza al 95%. RESULTADOS: De los 94 pacientes estudiados, 27 (28,7%) sufrieron algún episodio de EC. Ninguno falleció por esta causa. La afectación intestinal extensa, la necesidad de una ostomía de descarga en el proceso diagnóstico, la cirugía abierta y el diagnóstico anterior a los 7,2 meses de vida se asociaron en el análisis univariante a un mayor riesgo de desarrollar EC. En el multivariante, tan solo el diagnostico precoz y la cirugía abierta quedaron como variables asociadas al riesgo de EC. CONCLUSIONES: La EC sigue siendo una complicación habitual en la EdH, especialmente en las formas más largas y complejas. La identificación de los factores que la favorecen permitiría un mayor control, una mejor prevención secundaria ante el comienzo de los síntomas y un tratamiento más precoz, lo que lograría disminuir su morbilidad.

Factores de riesgo asociados al desarrollo de enterocolitis en la enfermedad de Hirschsprung / Risk factors associated with the development of enterocolitis in Hirschsprung's disease

Objetivo. La enterocolitis (EC) asociada a la enfermedad de Hirschsprung (EdH) es una entidad de etiopatogenia desconocida y potencialmente mortal. Nuestro objetivo es identificar los factores implicados en el desarrollo de EC en una cohorte de pacientes con EdH tratados en el nuestro centro. Métodos. Se revisaron los pacientes tratados por EdH en el periodo 2000-2016. Se incluyeron 94 pacientes, recogiendo de las historias clínicas variables demográficas y todas las relacionadas con la enfermedad. Se realizó un estudio de riesgo uni y multivariado usando como variable dependiente la existencia de un cuadro de enterocolitis. Los resultados se presentan con riesgo relativo (RR) con su intervalo de confianza al 95%. Resultados. De los 94 pacientes estudiados, 27 (28,7%) sufrieron algún episodio de EC. Ninguno falleció por esta causa. La afectación intestinal extensa, la necesidad de una ostomía de descarga en el proceso diagnóstico, la cirugía abierta y el diagnóstico anterior a los 7,2 meses de vida se asociaron en el análisis univariante a un mayor riesgo de desarrollar EC. En el multivariante, tan solo el diagnostico precoz y la cirugía abierta quedaron como variables asociadas al riesgo de EC. Conclusiones. La EC sigue siendo una complicación habitual en la EdH, especialmente en las formas más largas y complejas. La identificación de los factores que la favorecen permitiría un mayor control, una mejor prevención secundaria ante el comienzo de los síntomas y un tratamiento más precoz, lo que lograría disminuir su morbilidad (AU)

Objectives. Hirschsprung's-associated enterocolitis (HAEC) is a live-threatening complication that remains badly understood. Our objective is to identify the risk factors related to the development of HAEC in the cohort of patients with Hirschsprung's disease (HD) treated in our center. Methods. We reviewed the patients treated for HD between 2000 and 2016. Ninety four patients were included, and the clinical details related to the disease were evaluated. Our primary outcome measure was the development of HAEC. Relative risks are presented with 95% confidence intervals. Results. Twenty seven patients out of the ninety four (28.7%) suffered HAEC. None of them died from this complication. The extended aganglionosis, the need of a preoperative stoma, a transabdominal surgery and the diagnosis before the age of 7.2 months were related to a higher risk of suffering HAEC. Conclusions. HAEC remains a common complication in patients suffering from HD, especially those with complex forms. The identification of the risk factors could result in a better control of the HAEC, which lead to a faster diagnosis and treatment, reducing the morbimortality related to HAEC (AU)

Influence of Saccharomyces cerevisiae fermentation products, SmartCare in milk replacer and Original XPC in calf starter, on the performance and health of preweaned Holstein calves challenged with Salmonella enterica serotype Typhimurium.

This study was designed to investigate the effects of supplementing SmartCare (SC; Diamond V, Cedar Rapids, IA) in milk replacer and Original XPC (XPC; Diamond V) in calf starter on performance and health of preweaned calves following an oral challenge with Salmonella enterica. The study was performed in two 35-d periods with 30 Holstein bull calves (2 ± 1 d of age) per period. In each period, calves were blocked by location in the barn and randomly assigned to treatments that included control, base milk replacer and calf starter with no added Saccharomyces cerevisiae fermentation products; SC, milk replacer with 1 g of SC/calf per day and base calf starter; and SC+XPC, milk replacer with 1 g of SC/calf per day and calf starter with 0.5% XPC on a dry matter basis. Calves were fed 350 g of milk replacer solids at 14% dry matter twice daily at 0700 and 1700 h. Calf starter and water were offered ad libitum and intakes were recorded daily. Calves were challenged with 108 cfu of sulfamethazine-resistant Salmonella enterica serotype Typhimurium orally on d 14 of the study. Fecal Salmonella shedding was determined on d 14 to 21 (daily), 24, 28, and 35 using selective media. Blood samples were collected on d 0, 7, 14, 16, 18, 21, 24, 28, and 35 and analyzed for hematology; plasma were analyzed for haptoglobin concentrations. All data were reported as CON, SC, and SC+XPC, respectively. Calf starter intake was increased from d 22 to 35 among SC+XPC calves and from d 29 to 35 among SC calves. The SC+XPC calves had a lower neutrophil-to-lymphocyte ratio (0.81, 0.83, and 0.69 ± 0.051) throughout the study. The SC+XPC calves also had lower hematocrits (35.1, 35.3, and 33.4 ± 0.54%) and hemoglobin concentrations (10.8, 10.6, and 10.1 ± 0.16 mg/dL) throughout the study. We found a tendency for calves fed SC and SC+XPC to have more solid fecal scores during the week after the challenge. We observed no treatment or treatment × time differences on plasma haptoglobin concentrations (63, 48, and 60 ± 0.5 µg/mL). No treatment differences were observed in the fecal shedding of the Salmonella; however, we noted a tendency for a treatment difference in the percentage of calves positive for Salmonella present in the ileal tissue at d 21 after the challenge (25, 50, and 60%). Supplementing preweaned Holstein calves with both SC in milk replacer and XPC in calf starter improved starter intake and improved fecal consistency immediately after a mild Salmonella enterica challenge, but more data are needed to further understand how these yeast fermentation products influence the immune responses to Salmonella enterica.

Correlation of the fragility of metallic liquids with the high temperature structure, volume, and cohesive energy.

The thermal expansion coefficients, structure factors, and viscosities of twenty-five equilibrium and supercooled metallic liquids have been measured using an electrostatic levitation (ESL) facility. The structure factor was measured at the Advanced Photon Source, Argonne, using the ESL. A clear connection between liquid fragility and structural and volumetric changes at high temperatures is established; the observed changes are larger for the more fragile liquids. It is also demonstrated that the fragility of metallic liquids is determined to a large extent by the cohesive energy and is, therefore, predictable. These results are expected to provide useful guidance in the future design of metallic glasses.

Plane of nutrition influences the performance, innate leukocyte responses, and resistance to an oral Salmonella enterica serotype Typhimurium challenge in Jersey calves.

Two experiments investigated how plane of nutrition influences performance, leukocyte responses, and resistance to an oral Salmonella enterica serotype Typhimurium challenge. In experiment 1, 46 (2±1 d of age) calves were randomly assigned to 2 diets: a low (LPN; n=23) and high plane of nutrition (HPN; n=23). The LPN calves were fed 409 g/d of dry matter (DM) of a 20% crude protein and 20% fat milk replacer, whereas HPN calves were fed 610 and 735 g/d of DM of a 28% crude protein and 25% fat milk replacer during wk 1 and 2 to 6, respectively. In experiment 2, 20 bull calves (LPN; n=11 and HPN; n=9) were orally challenged on d 80 with 1.5×10(7) cfu of Salmonella Typhimurium (ATCC #14028). The HPN calves had a greater incidence (87.5 vs. 45.5%) and duration of days with high fecal scores (5.5 vs. 3.5 d). The LPN calves had greater neutrophil surface expression of L-selectin on d 7, 21, and 42. Following the Salmonella Typhimurium challenge, calf starter DM intake was greater among the HPN calves. The percentage of neutrophils producing an oxidative burst was also greater among HPN calves on d 1 to 5 after the challenge. Similarly, the intensity of the oxidative burst tended to be greater among the HPN calves on d 2 and 3 postchallenge. The secretion of tumor necrosis factor-α from whole-blood cultures stimulated with lipopolysaccharide tended to be greater on d 1 and was greater on d 5 and 6 among HPN calves. The median ranks of haptoglobin concentrations were greater and plasma zinc concentrations tended to be decreased among LPN calves. These data indicate that feeding a HPN to Jersey calves improved average daily gain and feed efficiency, but increased the incidence of high fecal scores during the first few weeks of life; however, the HPN Jersey calves may be more resistant to Salmonella Typhimurium after weaning.

Group housing of Holstein calves in a poor indoor environment increases respiratory disease but does not influence performance or leukocyte responses.

The objective of the current study was to determine if group-housing Holstein heifer calves in indoor pens with poor ventilation and drainage influences performance, health, leukocytes, and behavioral responses compared with individually housed calves. Ninety colostrum-fed calves (2 ± 1 d of age) were randomly assigned to 3 treatments: individually housed (G1; n=30 calves), 2 calves per pen (G2; n=30 calves), or 3 calves per pen (G3; n=30 calves). The space allowance per calf was 2.5m(2) for all treatment groups. All calves were fed 747 and 1,010 g/d of dry matter of a 28% CP and 20% fat milk replacer during the first 2 wk and wk 3 to 6, respectively. Weaning was initiated on d 46 by removing the evening feeding, and calves were completely weaned when they consumed 800 g/d of dry matter calf starter for 2 consecutive days after d 54. Calves were randomly commingled at d 90 in groups of 5 calves per pen in outdoors pens with an attached hutch. Peripheral blood was collected during the neonatal (3, 10, 21 d), weaning (46, 48, 54 d), and commingling periods (90, 93, 98 d) and was analyzed for neutrophil oxidative burst capacity when cocultured with an Escherichia coli, neutrophil surface L-selectin protein concentration, and whole blood secretion of tumor necrosis factor-α when cocultured with lipopolysaccharide. Behavior of each calf was assessed using 2 independent tests: an approach response to a human subject and the response of the calf when placed in an isolated cage. Calf starter intake was greater for G2 and G3 during wk 8 and 9, and also at wk 11 for G3 compared with G1. No treatment × time interaction or treatment effect for average daily gain was observed. Additionally, no treatment × time or treatment effect was noted for any leukocyte or biochemical variable of biological significance throughout the entire study. Individually housed calves tended to have a reduced incidence of respiratory disease during the first 90 d of life. No other treatment differences for the other health outcomes were observed. Group-housed calves also relied more on calf-to-calf interactions than calf-to-human interactions, as evident by their reduced approach of the human observer and more frequent movement when placed in an isolated pen. Group housing in an environment with poor ventilation and drainage may increase the risk of respiratory disease.

Improved performance and heightened neutrophil responses during the neonatal and weaning periods among outdoor group-housed Holstein calves.

The objective was to determine if outdoor group housing of Holstein calves influences metabolic status, leukocyte responses, and behavior compared with individually housed calves. Forty-nine Holstein heifer calves (2 ± 1 d of age) were randomly assigned to 1 of 2 treatments: individually housed (G1; n = 22) or group housed [3 calves per pen (G3); n = 27]. The space allowances per calf were 4.8 and 7.0m(2) for G1 and G3, respectively. All calves were offered an identical plane of milk replacer nutrition (747 and 1,010 g of DM/d of a 28% CP:20% fat milk replacer from wk 1 to 2 and wk 3 to 6, respectively). Weaning was initiated during wk 7 by removing the p.m. feeding and calves were completely weaned when they consumed 900 g of calf starter/d (as fed) for 2 consecutive days after d 54. At d 90, calves were commingled into random outdoor groups of 5 calves per pen. Peripheral blood was collected during the neonatal (d 3, 10, and 21), weaning (d 46, 48, and 54), and commingling periods (d 90, 93, and 98) and was analyzed for neutrophil oxidative burst (OB) capacity when cocultured with Escherichia coli, neutrophil surface L-selectin protein expression, and whole-blood secretion of tumor necrosis factor-α when cocultured with lipopolysaccharide. Starter intake was greater for G3 during the postweaning period (wk 8 to 12). Average daily gain was greater for G3 than G1 from d 54 to 68 and tended to be greater after commingling from d 113 to 133. During the neonatal period, G3 calves had more activated neutrophils, as evidenced by increased neutrophil L-selectin protein expression and a tendency for increased percentage of neutrophils producing an OB than G1 calves. During weaning, G3 calves continued to have more activated neutrophils with increased L-selectin expression on d 46 and 48 and a greater OB intensity throughout the period. No differences were observed among leukocyte responses between treatments at d 93 and 98. Outdoor group-housed Holstein calves had improved performance and heightened neutrophil responses compared with individually housed calves.

A compact rotating dilution refrigerator.

We describe the design and performance of a new rotating dilution refrigerator that will primarily be used for investigating the dynamics of quantized vortices in superfluid (4)He. All equipment required to operate the refrigerator and perform experimental measurements is mounted on two synchronously driven, but mechanically decoupled, rotating carousels. The design allows for relative simplicity of operation and maintenance and occupies a minimal amount of space in the laboratory. Only two connections between the laboratory and rotating frames are required for the transmission of electrical power and helium gas recovery. Measurements on the stability of rotation show that rotation is smooth to around 10(-3) rad s(-1) up to angular velocities in excess of 2.5 rad s(-1). The behavior of a high-Q mechanical resonator during rapid changes in rotation has also been investigated.

Plane of nutrition during the preweaning period but not the grower phase influences the neutrophil activity of Holstein calves.

Two experiments were conducted to determine the influence of plane of nutrition during (1) the pre- and immediate postweaning periods and (2) the grower phase on the performance and leukocyte responses of Holstein calves. In experiment 1, 39 (2 ± 1 d old) colostrum-fed heifer calves were randomly assigned to 2 planes of nutrition, a low (LPN; n = 19) and a high plane of nutrition (HPN; n = 20). Calves in the LPN treatment were offered 418 g/d of dry matter (DM) of a 20% crude protein (CP)/20% fat milk replacer, whereas calves in the HPN treatment were offered 747 and 1,010 g/d of DM of a 28% CP/20% fat milk replacer during wk 1 and wk 2 to 6, respectively. Calves were offered ad libitum access to a calf starter until the end of the study. Peripheral blood samples were collected on d 3, 10, 21, 45, 47, 53, and 91 for many ex vivo leukocyte responses and biochemical analyses. A nutrition × time interaction was present for average daily gain and feed efficiency (feed:gain ratio). A nutrition × time interaction existed for plasma glucose concentration. Neutrophil L-selectin expression was greater in calves fed the LPN than HPN on d 3 and 21. The percentage of neutrophils producing an oxidative burst (OB) when cocultured with Escherichia coli tended to be greater and was greater in calves fed the LPN than HPN on d 10 and 21, respectively. In addition, neutrophils from calves fed the LPN had greater OB intensity throughout the neonatal period (0 to 21 d). However, plasma haptoglobin was not different between the 2 planes of nutrition throughout the study. In experiment 2, 50 heifer calves that were all previously fed a HPN similar to that described for experiment 1 were randomly assigned to 2 planes of nutrition (HPN and LPN) during the grower phase (5 pens/treatment; 5 calves/pen). Calves fed the HPN during the grower phase were fed 4.1 kg of concentrate DM (pellets; 22.4% CP, DM basis) per head per day, whereas calves on the LPN during the grower phase were fed 1.6 kg of DM of the same concentrate per head per day. All calves were fed alfalfa hay (16.2% CP; DM basis) ad libitum. Overall, average daily gain was greater in HPN calves than LPN calves. No differences were noticed for concentrations of plasma urea nitrogen, glucose, neutrophil L-selectin expression, percentage of neutrophils producing OB, and plasma haptoglobin concentration between the 2 planes of nutrition. In summary, intake and performance were improved in calves fed the HPN than calves fed the LPN in both experiments. The neutrophil responses of calves fed an LPN were more active during the preweaning period than calves fed an HPN; however, this response was not observed during the immediate postweaning period or the grower phase.

Technical note: Determination of preanalysis storage temperature and time allowances for ex vivo innate immune responses.

Evaluation of ex vivo innate immune responses requires the transport of blood to a laboratory for analyses. Storage temperature and duration are highly variable in the published literature. The objective of the present study was to establish recommended storage temperature and duration for blood before analysis of several ex vivo innate immune responses in vitro. Peripheral blood was collected from 8 clinically healthy, 12-mo-old Holstein heifers and stored either on ice or at ambient temperature for 1.5, 3.5, 5.5, 7.5, 9.5, and 24 h before conducting analyses for lipopolysaccharide stimulated whole blood tumor necrosis factor-α (TNF-α) secretion, neutrophil L-selectin expression, and neutrophil phagocytic and oxidative burst capacities when exposed to an Escherichia coli. L-Selectin expression was greater in neutrophils stored on ice as early as 1.5 h after blood collection. In addition, when neutrophils were stored on ice, L-selectin expression at 24 h was not different from that at 1.5 h after blood collection. Measures of innate immune cell function, including whole blood TNF-α secretion and neutrophil phagocytic and oxidative burst abilities, were decreased in blood stored on ice. Both TNF-α secretion and neutrophil oxidative burst intensity did not differ at 24 h compared with 1.5 h after blood collection when blood was stored at ambient temperatures. These data indicate that both storage temperature and duration influence measures of innate immune responses. Therefore, storage durations should be minimized and storage protocols kept consistent to reduce the influences of storage conditions on experimental results.

Departures from the protocol during conduct of a clinical trial: a pattern from the data record consistent with a learning curve.

OBJECTIVE: Recognition of learning curves in medical skill acquisition has enhanced patient safety through improved training techniques. Clinical trials research has not been similarly scrutinised. The VALsartan In Acute myocardial iNfarcTion, a large multinational, pragmatic, randomised, double-blind, multicentre trial, was retrospectively evaluated for evidence of research conduct consistent with a performance "learning curve". DESIGN: Records provided protocol departure (deviations/violations) and documentation query data. For each site, analysis included patient order (eg, first, second), recruitment rate and first enrollment relative to study start date. SETTING: Computerised data from a trial coordinated by an academic research organisation collaborating with 10 academic and 2 commercial research organisations and an industry sponsor. Interventions 931 sites enrolled 14,703 patients. Departures were restricted to the first year. Exclusions included patient's death or loss to follow-up within 12 months and subjects enrolled 80th or higher at a site. Departures were assessed for variance with higher patient rank, more frequent recruitment and later start date. METHODS AND RESULTS: 12,367 patients at 931 sites were analysed. Departures were more common for patients enrolled earlier at a site (p<0.0001). For example, compared with the 30th patient, the first had 47% more departures. Departures were also more common with slower enrollment and site start closer to the trial start date (p<0.0001). Similar patterns existed for queries. CONCLUSIONS: Research performance improved during the VALsartan In Acute myocardial iNfarcTion consistent with a "learning curve". Although effects were not related to a change in outcome (mortality), learning curves in clinical research may have important safety, ethical, research quality and economic implications for trial conduct.

Fulminant Wilson's disease requiring liver transplantation in one monozygotic twin despite identical genetic mutation.

Acute decompensated Wilson's disease (WD) that presents as fulminant hepatic failure carries significant mortality without hepatic replacement. The abnormal gene implicated in WD, ATP7B, has been mapped to chromosome 13, and leads to decreased passage of copper from hepatocytes to bile. Excess copper accumulation exceeds hepatocyte storage capacity resulting in intracellular necrosis, apoptosis and cell death in various organs of the body. The hepatic injury induced by the abnormal accumulation of copper in WD has variable presentation such as acute hepatitis, rapid hepatic deterioration resembling fulminant hepatic failure, or as progressive chronic liver disease in the form of chronic active hepatitis or cirrhosis. There are reports in the literature describing monozygotic (identical) twins with similar hepatic progression requiring liver transplantation, however, with different neurological outcome after transplant. We report a case of one monozygotic twin presenting with acute liver failure requiring emergent liver transplantation while the other twin presented with mild liver disease, when both shared an identical genetic mutation.

An initial linkage map of the West Nile Virus vector Culex tarsalis.

We have constructed the first genetic linkage map for the North American arboviral vector Culex tarsalis. 120 F(2) offspring from a cross between two colonies were genotyped using 25 microsatellites and six inter-simple sequence repeat (ISSR) markers. We resolved four linkage groups which likely correspond to two full-length chromosomes and two arms of the final chromosome. The longest linkage group contains the sex locus and corresponds to chromosome 3. Recombination rates around the sex locus were dramatically higher in females compared to males. The majority of microsatellite loci share sequence identity with regions of the Culex quinquefasciatus genome, whose assembly should aid in anchoring linkage groups to physical chromosomes. This map will aid in identification of loci involved with variable phenotypes in C. tarsalis including WNV susceptibility.

Factors affecting primary care provider and caregiver concordance for pediatric asthma medications.

BACKGROUND: Lack of discussion regarding actual asthma medication use by physicians with caregivers of children with asthma may result in low caregiver and physician concordance about prescribed asthma medications. OBJECTIVE: The primary objective was to examine the concordance between primary care providers (PCP) and caregivers regarding child asthma medication use. METHODS: Current asthma medications in the home with verification from each child's PCP were obtained for 231 underserved children with persistent asthma. Kappas and chi-square statistics were calculated to measure the strength of the concordance. Caregiver and PCP dyads were categorized as concordant or discordant based on asthma medication use. RESULTS: For all asthma prescriptions N = 479, two thirds of caregiver-PCP dyads (67.8) were categorized as concordant with at least one asthma medication. Concordance for asthma medications varied by type of medication ranging from 84% agreement for albuterol and 77% agreement for Flovent. In the final regression model predicting caregiver and PCP concordance, the number of PCP visits within the past 6 months and caregiver report of no limitation of child's activity due to asthma were significantly higher in caregivers who were considered concordant with their child's PCP while controlling for child age and frequency of symptom nights and number of ED visits in prior 6 months. In a model predicting the number of PCP visits, the number of ED visits was the only significant variable associated with the number of PCP visits while controlling for caregiver and PCP concordance. CONCLUSION: Caregiver and PCP concordance was significantly associated with increased number of PCP visits suggesting that increased exposure to a health care provider may increase agreement between a child's PCP and caregiver regarding prescribed asthma medications. However, there may be other important factors including increased emergency department visits that may also be associated with subsequent pediatric primary care visits for asthma.