Relative contributions of large-scale and wedgelet currents in the substorm current wedge.

We examined how much large-scale and localized upward and downward currents contribute to the substorm current wedge (SCW), and how they evolve over time, using the THEMIS all-sky imagers (ASIs) and ground magnetometers. One type of events is dominated by a single large-scale wedge, with upward currents over the surge and broad downward currents poleward-eastward of the surge. The other type of events is a composite of large-scale wedge and wedgelets associated with streamers, with each wedgelet having comparable intensity to the large-scale wedge currents. Among 17 auroral substorms with wide ASI coverage, the composite current type is more frequent than the single large-scale wedge type. The dawn-dusk size of each wedgelet is ~ 600 km in the ionosphere (~ 3.2 R E in the magnetotail, comparable to the flow channel size). We suggest that substorms have more than one type of SCW, and the composite current type is more frequent.

Master regulator for chondrogenesis, Sox9, regulates transcriptional activation of the endoplasmic reticulum stress transducer BBF2H7/CREB3L2 in chondrocytes.

The endoplasmic reticulum (ER) stress transducer, box B-binding factor 2 human homolog on chromosome 7 (BBF2H7), is a basic leucine zipper (bZIP) transmembrane transcription factor. This molecule is activated in response to ER stress during chondrogenesis. The activated BBF2H7 accelerates cartilage matrix protein secretion through the up-regulation of Sec23a, which is responsible for protein transport from the ER to the Golgi apparatus and is a target of BBF2H7. In the present study, we elucidated the mechanisms of the transcriptional activation of Bbf2h7 in chondrocytes. The transcription of Bbf2h7 is regulated by Sex determining region Y-related high-mobility group box 9 (Sox9), a critical factor for chondrocyte differentiation that facilitates the expression of one of the major cartilage matrix proteins Type II collagen (Col2), through binding to the Sox DNA-binding motif in the Bbf2h7 promoter. BBF2H7 is activated as a transcription factor in response to physiological ER stress caused by abundant synthesis of cartilage matrix proteins, and consequently regulates the secretion of cartilage matrix proteins. Taken together, our findings demonstrate novel regulatory mechanisms of Sox9 for controlling the secretion of cartilage matrix proteins through the activation of BBF2H7-Sec23a signaling during chondrogenesis.

Granulation compared to co-application of biochar plus mineral fertilizer and its impacts on crop growth and nutrient leaching.

Mechanized biochar field application remains challenging due to biochar's poor flowability and bulk density. Granulation of biochar with fertilizer provides a product ready for application with well-established machinery. However, it's unknown whether granulated biochar-based fertilizers (gBBF) are as effective as co-application of non-granulated biochar with fertilizer. Here, we compared a gBBF with a mineral compound fertilizer (control), and with a non-granulated biochar that was co-applied at a rate of 1.1 t ha-1 with the fertilizer in a white cabbage greenhouse pot trial. Half the pots received heavy rain simulation treatments to investigate nutrient leaching. Crop yields were not significantly increased by biochar without leaching compared to the control. With leaching, cabbage yield increased with gBBF and biochar-co-application by 14% (p > 0.05) and 34% (p < 0.05), respectively. Nitrogen leaching was reduced by 26-35% with both biochar amendments. Biochar significantly reduced potassium, magnesium, and sulfur leaching. Most nitrogen associated with gBBF was released during the trial and the granulated biochar regained its microporosity. Enriching fertilizers with biochar by granulation or co-application can improve crop yields and decrease nutrient leaching. While the gBBF yielded less biomass compared to biochar co-application, improved mechanized field application after granulation could facilitate the implementation of biochar application in agriculture.

Acquired Bronchobiliary Fistula in a Young Adult Patient With Sepsis: A Case Report.

Bronchobiliary fistula (BBF) is a rare, highly morbid condition that results from an abnormal connection between biliary channels and the bronchial tree. In the past, this condition has been known to be caused by untreated hydatid cysts or hepatic abscesses that can erode through the diaphragm into the pleural cavity and bronchial tree, creating fistulation. However, the condition's spectrum has changed in recent years, and BBFs have also become associated with neoplasm, iatrogenic causes, and trauma. Cases of BBF are treated differently, either with simple conservative management or invasive surgery. We present a case of a 46-year-old male initially presenting with sepsis, who was found to have a BBF. The diagnosis was made after a hepatobiliary iminodiacetic acid scan showed the flow of a tracer in the lung fields. The condition was likely due to acute cholecystitis and prior biliary instrumentation. The patient was treated successfully with percutaneous cholecystostomy tube insertion followed by elective laparoscopic cholecystectomy several weeks after hospital discharge.

Rapid qualitative and quantitative analysis of benzo(b)fluoranthene (BbF) in shrimp using SERS-based sensor coupled with chemometric models.

Benzo(b)fluoranthene (BbF), a polycyclic aromatic hydrocarbon (PAH), is a carcinogenic contaminant of concern in seafood. This study developed a simple, rapid, sensitive, and cost-effective surface-enhanced Raman scattering (SERS) sensor (AuNPs) coupled with chemometric models for detecting BbF in shrimp samples. Partial least squares (PLS) regression models were optimized using uninformative variable elimination (UVE), bootstrapping soft shrinkage (BOSS), and competitive adaptive reweighted sampling (CARS). Qualitative analysis was performed using principal component analysis (PCA), linear discriminant analysis (LDA), and k-nearest neighbors (KNN) to differentiate between BbF-contaminated and uncontaminated shrimp samples. The SERS-sensor exhibited excellent sensitivity (LOD = 0.12 ng/mL), repeatability (RSD = 6.21%), and anti-interference performance. CARS-PLS model demonstrated superior predictive ability (R2 = 0.9944), and qualitative analysis discriminated between contaminated and uncontaminated samples. The sensor's accuracy was validated using HPLC, demonstrating the ability of the SERS-sensor coupled with chemometrics to rapidly and reliably detect BbF in shrimp samples.

Benzo(k)fluoranthene and benzo(b)fluoranthene degradation by Selenastrum capricornutum and identification of metabolites using HPLC-FD and HPLC-ESI-QqQ-MS/MS.

Selenastrum capricornutum efficiently degrades high molecular weight polycyclic aromatic hydrocarbons (HMW PAHs). Until now, there are few studies on the benzo(k)fluoranthene (BkF) and benzo(b)fluoranthene (BbF) biodegradation by this microalga. For this reason, in the present work, extracts obtained from cultures of S. capricornutum were incubated with BkF and BbF individually, and analyzed by HPLC with fluorescence and different mass spectrometry detection modes: i) the HPLC-ESI(+)-MS/MS (MRM mode) analysis that confirmed the formation of monohydroxylated and dihydrodiol metabolites indicating that these PAHs could be simultaneously degraded through the monooxygenase and dioxygenase; ii) HPLC-ESI(+)-MS (full scan mode) that showed the formation of key metabolites containing four and two aromatic rings possibly resulting from aromatic ring-opening oxygenases, not known until now in microalgae; iii) HPLC-FD analysis that confirmed the individual BkF and BbF degradation occurring in extra- and intra-cellular extracts, indicating that an oxygenase enzyme complex is released by microalgae cells to the external environment to perform HMW PAHs biodegradation. So, this work presents new insights into the metabolic pathways of BkF and BbF biodegradation by S. capricornutum; likewise, the intra- and extra-cellular extracts of this microalgae have great potential to be applied in environmental procedures.

Effects of silodosin, a selective α1A-adrenoceptor antagonist, on bladder blood flow and bladder function in a rat model of atherosclerosis induced chronic bladder ischemia without bladder outlet obstruction.

PURPOSE: We investigated the effects of the selective α1A-adrenoceptor antagonist silodosin on bladder blood flow and bladder function in a rat model of atherosclerosis induced chronic bladder ischemia without bladder outlet obstruction. MATERIALS AND METHODS: The chronic bladder ischemia model was prepared by creating balloon endothelial injury of the bilateral iliac arteries in male rats. Using an osmotic pump, chronic bladder ischemia rats received silodosin subcutaneously at a rate of 0.1 or 0.3 mg/kg per day, or vehicle for 8 weeks. All groups received a 2% cholesterol diet throughout the experiment. For each α1-adrenoceptor subtype mRNA expression in bladder microvessels was examined by in situ hybridization. Bladder blood flow was measured using a laser speckle blood flow imager. Malondialdehyde in bladder tissue and 8-hydroxy-2'-deoxyguanosine in urine were measured as markers of oxidative stress. A metabolic cage study and cystometry were performed in conscious rats. RESULTS: The expression of all α1-adrenoceptor subtype mRNA was observed in rat bladder microvessels. Silodosin abrogated the decreased bladder blood flow in the empty bladder and during bladder distention that were evident in rats with chronic bladder ischemia. Levels of oxidative stress markers in these rats were significantly decreased by silodosin administration. Silodosin ameliorated bladder dysfunction in rats with chronic bladder ischemia in the metabolic cage study and on cystometry. CONCLUSIONS: Results suggest that in ischemic conditions α1-adrenoceptor antagonists such as silodosin may improve bladder function by restoring bladder blood flow.

Evaluating the adhesive potential of the newly isolated bacterial strains in research exploitation of plant microbial interaction.

Bacterial adhesion potential constitutes the transition of bacteria from the planktonic to the static phase by promoting biofilm formation, which plays a significant role in plant-microbial interaction in the agriculture industry. In present study, the adhesion potential of five soil-borne bacterial strains belonging to different genera was studied. All bacterial strains were capable of forming colonies and biofilms of different levels of firmness on polystyrene. Significant variation was observed in hydrophobicity and motility assays. Among the five bacterial strains (SH-6, SH-8, SH-9, SH-10, and SH-19), SH-19 had a strong hydrophobic force, while SH-10 showed the most hydrophilic property. SH-6 showed great variability in motility; SH-8 had a swimming diffusion diameter of 70 mm, which was three times higher than that of SH-19. In the motility assay, SH-9 and SH-10 showed diffusion diameters of approximately 22 mm and 55 mm, respectively. Furthermore, among the five strains, four are predominately electron donors and one is electron acceptors. Overall, positive correlation was observed among Lewis acid base properties, hydrophobicity, and biofilm forming ability. However, no correlation of motility with bacterial adhesion could be found in present experimental work. Scanning electron microscopy images confirmed the adhesion potential and biofilm ability within extra polymeric substances. Research on the role of adhesion in biofilm formation of bacteria isolated from plants is potentially conducive for developing strategies such as plant-microbial interaction to mitigate the abiotic stress.

The Behavior-Driven Mechanism of Consumer Participation in "Carbon Neutrality": Based on the Promotion of Replacing Coal with Biomass Briquette Fuel.

"replacing coal with biomass briquette fuel" can effectively reduce carbon emissions. This study takes this as an example to discuss consumers' "willingness to consume (WTC)", "willingness to spend (WTS)" and related influencing factors to find the behavior-driven mechanism of consumer participation in "carbon neutrality". Through the survey and analysis, the results show that 81.64% of the respondents support to consume Biomass Briquette Fuel (BBF) to replace coal. The annual WTS is 157.78 CNY per capita. The factors, such as the education, the relevant government policy support cognition, the level of cognition of health concepts, ecological environmental protection and resource regeneration, have a significant positive impact on the promotion in rural areas. Finally, we put forward corresponding policy recommendations. It provides a reference for motivating consumers to participate in "carbon neutrality" and promoting rural energy transformation to achieve the goal of "carbon neutrality".

Occupational Exposure to Blood and Body Fluids amongst Health Care Workers in a Teaching Hospital of the Armed Forces.

BACKGROUND: Health care workers (HCWs) are at risk of infection with blood-borne viruses in the course of their work. Over 90% of these infections are occurring in low-income countries and most are preventable. However, the situation in the Armed Forces hospitals has always been thought to be much better than the public health facilities in India. The focus of the study was on assessing the exposure frequency amongst HCWs in a teaching hospital in the Armed Forces. METHODS: A cross-sectional survey amongst HCWs involved in collecting blood samples and administering injections in all wards of the hospital was conducted. Selection of study participants was by simple random sampling. A pre-tested questionnaire was administered by unlinked, anonymous method. RESULT: Total sample studied was 70. The proportion of HCWs experiencing exposure to blood body fluid splash (BBF) and needlestick injury (NSI) during last one week was 47.1 % and 31.43 %, respectively. The incidence density of BBF exposure was 537.14 per 100 person years and that of NSI episodes was 228.57 per 100 person years. The reasons for not using personal protective equipment (PPE) ranged from busy schedule (37.14%), non use of PPE by co-workers (67.14%), emergencies (91.43%) risk that patients may get offended by PPE use by HCWs (27.14%) to discomfort while using PPE (24.29%). All components of PPE were available as per only 34.29 percent. CONCLUSION: The high level of occupational exposure to blood and body fluids and consequent risk of infection amongst a group of HCWs in the Armed Forces highlights the urgent need for interventions to enhance the occupational safety of workers.

Diagnosis of bronchobiliary fistula by bilirubin crystallization in the alveolar lavage fluid: case reports and literature review.

Bronchobiliary fistula (BBF) refers to the abnormal traffic between the biliary tract and the bronchus. The condition is very rare and usually develops secondary to liver echinococcosis or amebiasis, liver abscess, trauma, biliary obstruction, or tumors. BBF has a high mortality rate and currently, there are no accurate and effective diagnostic methods. This study reports the diagnosis and treatment of two patients with BBF which were confirmed by detecting bilirubin crystallization in the sputum. The first patient was a 45-year-old woman admitted to the hospital with "recurrent cough and lung infection". She had a history of multiple biliary tract surgeries and bilirubin crystallization was detected in bronchoalveolar lavage fluid (BALF) upon examination. Computed tomography (CT) imaging and magnetic resonance cholangiopancreatography (MRCP), together with clinical features, confirmed a diagnosis of BBF. The second patient was a 53-year-old woman admitted to the hospital with coughing and bile-like sputum. She had a history of cholangiocarcinoma surgery and bilirubin crystallization was detected in the cytomorphological BALF examination. Endoscopic retrograde cholangiopancreatography (ERCP) combined with clinical features confirmed a diagnosis of BBF. Both patients recovered after treatment and were discharged from the hospital. The clinical diagnosis of BBF largely relies upon imaging combined with clinical standards, and BALF examinations are rarely performed. This current investigation retrospectively analyzed the diagnosis and treatment of two cases of BBF, and demonstrated that bilirubin crystallization in the BALF may be an important diagnostic indicator for BBF.

Toxic effects of endoplasmic reticulum stress transducer BBF2H7-derived small peptide fragments on neuronal cells.

Aggregation, fibril formation, and deposition of amyloid ß (Aß) protein are believed to be the central pathogeneses of Alzheimer's disease (AD). Numerous studies have shown that fibril formation is promoted by preformed seeds at the beginning of the aggregation process. Therefore, aggregated molecules that promote fibrillization of Aß protein as seeds could affect the pathology. We recently found that approximately 40 amino acid hydrophobic peptides, BBF2H7-derived small peptide (BSP) fragments, are generated via intramembranous cleavage under endoplasmic reticulum (ER) stress conditions. Interestingly, similar to Aß protein, the fragments exhibit a high aggregation propensity and form fibril structures. It has been noted that ER stress is involved in the pathogenesis of AD. In this study, we examined the effect of BSP fragments on aggregation and cytotoxicity of Aß1-40 protein, which is generated as a major species of Aß protein, but has a lower aggregative property than Aß1-42 protein. We demonstrated that BSP fragments promote aggregation of Aß1-40 protein. Aggregates of Aß1-40 protein mediated by BSP fragments also exhibited potent neurotoxicity. Our findings suggest the possibility that BSP fragments affect accumulation of Aß proteins and are involved in the pathogenesis of AD.

Bile in bronchi: A case report.

BACKGROUND: The biliary bronchial fistula is rare and difficult to treat. Here we report a 49-year-old woman diagnosed with biliary bronchial fistula due to cough with yellow-green sputum. CASE PRESENTATION: this is a typical case of the biliary bronchial fistula with typical symptoms. The position of the abscess cavity below the diaphragm could not be catheter drainage. After anti-infection treatment, yellow-green sputum was reduced. Follow-up showed a good prognosis. CONCLUSION: biliary bronchial fistula is rare in the clinic, combined with chest and abdomen infection.

An analysis of stakeholder networks to support the breastfeeding scale-up environment in Mexico.

Little information exists on how to garner political commitment to strengthen large-scale breastfeeding policies and programmes by targeting key decision makers. The present study aims to map and describe the influence of stakeholders involved in breastfeeding policy and programming and identify opportunities to strengthen the breastfeeding-friendly environment in Mexico. A total of nine key informants from seventeen stakeholder organisations were selected based on their in-depth knowledge of the breastfeeding environment in Mexico and were individually interviewed using Net-Map methodology. This participatory interview technique combines stakeholder mapping, social network analysis and influence mapping to identify relevant stakeholders. Participants identified a total of fifty-five stakeholders shaping breastfeeding programmes and policies through four domains of influence: commands (n 32 stakeholders), dissemination (n 40), funding (n 35) and technical assistance (n 37). The Federal Ministry of Health emerged as the most influential stakeholder of breastfeeding policy and programming decisions in Mexico among all domains of influence. The Ministry of Finance and Public Credit as well as the National Institute of Public Health were identified as additional key stakeholders providing funding and technical assistance to the Federal Ministry of Health, respectively. Engaging identified key stakeholders can generate a multisectoral commitment to breastfeeding and strengthen the breastfeeding-friendly environment in Mexico.

How virus size and attachment parameters affect the temperature sensitivity of virus binding to host cells: Predictions of a thermodynamic model for arboviruses and HIV.

Virus binding to host cells involves specific interactions between viral (glyco)proteins (GP) and host cell surface receptors (Cr) (protein or sialic acid (SA)). The magnitude of the enthalpy of association changes with temperature according to the change in heat capacity (ΔCp) on GP/Cr binding, being little affected for avian influenza virus (AIV) haemagglutinin (HA) binding to SA (ΔCp = 0 kJ/mol/K) but greatly affected for HIV gp120 binding to CD4 receptor (ΔCp = -5.0 kJ/mol/K). A thermodynamic model developed here predicts that values of ΔCp from 0 to ~-2.0 kJ/mol/K have relatively little impact on the temperature sensitivity of the number of mosquito midgut cells with bound arbovirus, while intermediate values of ΔCp of ~-3.0 kJ/mol/K give a peak binding at a temperature of ~20 °C as observed experimentally for Western equine encephalitis virus. More negative values of ΔCp greatly decrease arbovirus binding at temperatures below ~20 °C. Thus to promote transmission at low temperatures, arboviruses may benefit from ΔCp ~ 0 kJ/mol/K as for HA/SA and it is interesting that bluetongue virus binds to SA in midge midguts. Large negative values of ΔCp as for HIV gp120:CD4 diminish binding at 37 °C. Of greater importance, however, is the decrease in entropy of the whole virus (ΔSa_immob) on its immobilisation on the host cell surface. ΔSa_immob presents a repulsive force which the enthalpy-driven GP/Cr interactions weakened at higher temperatures struggle to overcome. ΔSa_immob is more negative (less favourable) for larger diameter viruses which therefore show diminished binding at higher temperatures than smaller viruses. It is proposed that small size phenotype through a less negative ΔSa_immob is selected for viruses infecting warmer hosts thus explaining the observation that virion volume decreases with increasing host temperature from 0 °C to 40 °C in the case of dsDNA viruses. Compared to arboviruses which also infect warm-blooded vertebrates, HIV is large at 134 nm diameter and thus would have a large negative ΔSa_immob which would diminish its binding at human body temperature. It is proposed that prior non-specific binding of HIV through attachment factors takes much of the entropy loss for ΔSa_immob so enhancing subsequent specific gp120:CD4 binding at 37 °C. This is consistent with the observation that HIV attachment factors are not essential but augment infection. Antiviral therapies should focus on increasing virion size, for example through binding of zinc oxide nanoparticles to herpes simplex virus, hence making ΔSa_immob more negative, and thus reducing binding affinity at 37 °C.

Towards a thermodynamic mechanistic model for the effect of temperature on arthropod vector competence for transmission of arboviruses.

Arboviruses such as West Nile virus (WNV), bluetongue virus (BTV), dengue virus (DENV) and chikungunya virus (CHIKV) infect their arthropod vectors over a range of average temperatures depending on the ambient temperature. How the transmission efficiency of an arbovirus (i.e. vector competence) varies with temperature influences not only the short term risk of arbovirus outbreaks in humans and livestock but also the long term impact of climate change on the geographical range of the virus. The strength of the interaction between viral surface (glyco)protein (GP) and the host cell receptor (Cr) on binding of virus to host cell is defined by the thermodynamic dissociation constant Kd_receptor which is assumed to equal 10-3 M (at 37 °C) for binding of a sialic acid (SA) on the arthropod midgut epithelial cell surface to a SA-binding site on the surface of BTV, for example. Here virus binding affinity is modelled with increasing number of GP/Cr contacts at temperatures from 10 °C to 35 °C taking into account the change in entropy on immobilization of the whole virus on binding (ΔSa_immob). Based on published data, three thermodynamic GP/Cr binding scenarios, namely enthalpy-driven, entropy-assisted and entropy-driven, are shown to affect the temperature sensitivity of virus binding in different ways. Thus for enthalpy-driven GP/Cr binding, viruses bind host cells much more strongly at 10 °C than 35 °C. A mechanistic model is developed for the number of arthropod midgut cells with bound virus and by building in a kinetic component for the rate of arbovirus replication and subsequent spread to the arthropod salivary glands, a model for the effect of temperature on vector competence is developed. The model separates the opposing effects of temperature on midgut cell binding affinity from the kinetic component of virogenesis. It successfully accommodates both increases in vector competence with temperature as for DENV and WNV in mosquitoes and decreases as for the CHIKV 2010-1909 strain in various populations of Aedes albopictus mosquitoes. Enhanced cell binding at lower temperatures through enthalpy-driven GP/Cr binding compensates for the lower replication rate to some degree such that some transmission can still occur at lower temperatures. In contrast, the strength of entropy-driven GP/Cr binding diminishes at low temperatures although there is no minimum temperature threshold for transmission efficiency. The magnitude of ΔSa_immob is an important data gap. It is concluded that thermodynamic and kinetic data obtained at the molecular level will prove important in modelling vector competence with temperature.

Transposed Basilic Vein Fistula: A Credible Option.

Objective: Native fistula creation for hemodialysis in patients who have exhausted all their superficial veins presents a challenge to vascular practice. We review our experience in transposed basilic vein fistula (BVT) creation and its usage for hemodialysis. Materials and Methods: We analyzed the hospital operative registry from January 2009 till June 2012 to identify the total number of BVT created in our center. Medical records of all patients were traced, and patients were interviewed using a standard proforma. In our center, BVT is performed as a two-stage procedure. All patients were routinely assessed with duplex scan preoperatively and postoperatively. Results: Two hundred thirty-nine patients were recruited in the study. Of these patients, 50.6% were male and 49.4% were female. Mean age was 53.4 years. Of these patients, 81.2% had history of other previous fistula creation. Risk factors profile includes diabetes mellitus in 59.8%, hypertension in 86.2%, and smoking in 13.0%. Of these patients, 84.5% had no operative complication. Commonest complication was wound infection, 6.3%, followed by hemorrhage or hemotoma required surgical intervention, 5.9%, and pseudoaneurysm, 1.3%. Primary and secondary patencies were at 84.2% and 86.1% at 1 year and 67.7% and 70.5% at 3 years, respectively. Conclusion: BVT is a credible option for challenging patients with absence of superficial veins for native fistula creation with good patency and low operative complication rate. Preoperative ultrasound assessment improves patient selection and outcome of BVT.

Magnetotail Fast Flow Occurrence Rate and Dawn-Dusk Asymmetry at XGSM ∼ -60 RE.

As a direct result of magnetic reconnection, plasma sheet fast flows act as primary transporter of mass, flux, and energy in the Earth's magnetotail. During the last decades, these flows were mainly studied within XGSM>-60RE , as observations near or beyond lunar orbit were limited. By using 5 years (2011-2015) of ARTEMIS (Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moons Interaction with the Sun) data, we statistically investigate earthward and tailward flows at around 60 RE downtail. A significant fraction of fast flows is directed earthward, comprising 43% (vx >400 km/s) to 56% (vx >100 km/s) of all observed flows. This suggests that near-Earth and midtail reconnection are equally probable of occurring on either side of the ARTEMIS downtail distance. For fast convective flows (v⊥x >400 km/s), this fraction of earthward flows is reduced to about 29%, which is in line with reconnection as source of these flows and a downtail decreasing Alfvén velocity. More than 60% of tailward convective flows occur in the dusk sector (as opposed to the dawn sector), while earthward convective flows are nearly symmetrically distributed between the two sectors for low AL (>-400 nT) and asymmetrically distributed toward the dusk sector for high AL (<-400 nT). This indicates that the dawn-dusk asymmetry is more pronounced closer to Earth and moves farther downtail during high geomagnetic activity. This is consistent with similar observations pointing to the asymmetric nature of tail reconnection as the origin of the dawn-dusk asymmetry of flows and other related observables. We infer that near-Earth reconnection is preferentially located at dusk, whereas midtail reconnection (X >- 60RE ) is likely symmetric across the tail during weak substorms and asymmetric toward the dusk sector for strong substorms, as the dawn-dusk asymmetric nature of reconnection onset in the near-Earth region progresses downtail.

Sterile Reverse Osmosis Water Combined with Friction Are Optimal for Channel and Lever Cavity Sample Collection of Flexible Duodenoscopes.

INTRODUCTION: Simulated-use buildup biofilm (BBF) model was used to assess various extraction fluids and friction methods to determine the optimal sample collection method for polytetrafluorethylene channels. In addition, simulated-use testing was performed for the channel and lever cavity of duodenoscopes. MATERIALS AND METHODS: BBF was formed in polytetrafluorethylene channels using Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. Sterile reverse osmosis (RO) water, and phosphate-buffered saline with and without Tween80 as well as two neutralizing broths (Letheen and Dey-Engley) were each assessed with and without friction. Neutralizer was added immediately after sample collection and samples concentrated using centrifugation. Simulated-use testing was done using TJF-Q180V and JF-140F Olympus duodenoscopes. RESULTS: Despite variability in the bacterial CFU in the BBF model, none of the extraction fluids tested were significantly better than RO. Borescope examination showed far less residual material when friction was part of the extraction protocol. The RO for flush-brush-flush (FBF) extraction provided significantly better recovery of E. coli (p = 0.02) from duodenoscope lever cavities compared to the CDC flush method. DISCUSSION AND CONCLUSION: We recommend RO with friction for FBF extraction of the channel and lever cavity of duodenoscopes. Neutralizer and sample concentration optimize recovery of viable bacteria on culture.