CFD-DEM Fluidized Bed Drying Study Using a Coarse-Graining Technique.

Fluidized beds are commonly applied to industrial drying applications. Modeling using the computational fluid dynamics-discrete element method (CFD-DEM) can be employed to increase the fundamental understanding of solids drying. A large drawback of CFD-DEM is the computational requirements, leading to a limitation regarding the system size. Coarse-grained CFD-DEM is an approach to reduce computational costs, allowing one to simulate larger fluidized beds. In this article, coarse-graining CFD-DEM scaling laws are used for fluidized bed solids drying. Three superficial gas velocities are investigated. The particle temperature and density are accurately described. Besides, the Sherwood number is well captured by the coarse-graining simulations.

[German S1 Guideline Long-/Post-COVID]. / S1-Leitlinie Long-/Post-COVID.

The German Society of Pneumology initiated 2021 the AWMF S1 guideline Long COVID/Post-COVID. In a broad interdisciplinary approach, this S1 guideline was designed based on the current state of knowledge.The clinical recommendations describe current Long COVID/Post-COVID symptoms, diagnostic approaches, and therapies.In addition to the general and consensus introduction, a subject-specific approach was taken to summarize the current state of knowledge.The guideline has an explicit practical claim and will be developed and adapted by the author team based on the current increase in knowledge.

Challenges of Case Management of COVID-19 in University of Uyo Teaching Hospital: A One-Year Experience.

BACKGROUND AND OBJECTIVES: Coronavirus disease 2019 (COVID-19) is a global pandemic. Older people and those with poorly controlled co-morbidities have higher risk of mortality. This study was conducted to highlight the clinical features, challenges of management and outcome for the patients we have seen in our centre over the past one year. METHODS: This was a retrospective cross-sectional study involving all patients admitted in the COVID-19 Isolation unit of University of Uyo Teaching Hospital (UUTH) from June, 2020-May, 2021. Clinical and laboratory information were obtained from the patient case notes. Ethical clearance for the conduct of the study was obtained from the Ethics committee, UUTH, Uyo. Data was analysed with STATA version 13. RESULTS: Thirty-three (37.9%) patients were COVID-19 PCR positive. The mean ± SD age of COVID-19 PCR positive patients was 57.3 ± 13.4 years with majority (69.7%) being above 50 years. There was a male preponderance (75%). Eleven (34.4%) patients died while 21(65.6%) were discharged. The highest co-morbidity associated with COVID-19 mortality was diabetes mellitus (7 out of 11; 63.6%). There was a poor uptake of supportive investigations for the management of COVID-19 patients. A raised body temperature (P=0.0006), a low SPO2 (0.00004), high respiratory rate (0.0009) on admission and shorter duration of admission (0.0002), were associated with mortality. CONCLUSION: The presence of co-morbidities, fever, low SPO2 and high respiratory rates on admission are associated with increased mortality from COVID-19 disease. A paucity of supportive investigations was a major challenge to COVID-19 management. We therefore recommend the strengthening of our laboratory capacity.

CONTEXTE ET OBJECTIFS: La maladie de coronavirus 2019 (COVID-19) est une pandémie mondiale. Les personnes âgées et celles qui présentent des comorbidités mal contrôlées ont un risque de mortalité plus élevé. Cette étude a été menée pour mettre en évidence les caractéristiques cliniques, les défis de la gestion et le résultat des patients que nous avons vus dans notre centre au cours de la dernière année. MÉTHODES: Il s'agissait d'une étude transversale rétrospective impliquant tous les patients admis dans l'unité d'isolement COVID- 19 de l'University of Uyo Teaching Hospital (UUTH) de juin 2020 à mai 2021. Les informations cliniques et de laboratoire ont été obtenues à partir des notes de cas des patients. L'autorisation éthique pour la réalisation de l'étude a été obtenue auprès du comité d'éthique de l'UUTH, Uyo. Les données ont été analysées avec STATA version 13. RÉSULTATS: Trente-trois (37,9%) patients étaient positifs à la PCR COVID-19. L'âge moyen ± SD des patients positifs au COVID-19 PCR était de 57,3 ± 13,4 ans, la majorité (69,7%) ayant plus de 50 ans. Il y avait une prépondérance masculine (75 %). Onze (34,4 %) patients sont décédés et 21 (65,6 %) sont sortis de l'hôpital. La comorbidité la plus importante associée à la mortalité de COVID-19 était le diabète miletus (7 sur 11 : 63 : 6 %). Les investigations de soutien pour la gestion des patients COVID-19 ont été peu utilisées. Une température corporelle élevée (P=0,0006), une faible SPO2 (0,00004), une fréquence respiratoire élevée (0,0009) à l'admission et une durée d'admission plus courte (0,0002) étaient associées à la mortalité. CONCLUSION: La présence de comorbidités, de fièvre, d'une faible SPO2 et d'une fréquence respiratoire élevée à l'admission est associée à une mortalité accrue de la maladie de COVID-19. Le manque d'investigations de soutien a été un défi majeur pour la gestion de la maladie COVID-19. Nous recommandons donc le renforcement de la capacité de nos laboratoires. Mots clés: COVID-19, défis, gestion des cas, Nigeria.

Psychological distress and health-related quality of life among stable patients with bronchiectasis.

BACKGROUND: Bronchiectasis is characterized by chronic symptoms and impaired physical activity. Anxiety and depression usually complicate chronic illness. Thus, underdiagnosis of psychological distress in bronchiectasis may lead to increased morbidity and mortality. AIMS: The aim of this study is to evaluate the impact of physical illness on psychological distress and its association with health-related quality of life (HRQOL). SUBJECTS AND METHODS: This is a cross-sectional study of adults with bronchiectasis. Patients completed a study questionnaire, the hospital anxiety and depression scale and the World Health Organization quality of life brief (WHOQOL-BREF) questionnaire. Physical examination was conducted on all participants. RESULTS: 103 patients were recruited for this study: 54 males (52.4%) and 49 females (47.6%). The average age of the patients was 49.12 ± 14.37 years. The most common predisposing factor for bronchiectasis amongst the patients was previous pulmonary tuberculosis (51 patients, 49.5%). Chronic productive cough, which was reported by 98 of the subjects (95.15%), was the most common symptom. 89 subjects (86.41%) reported episodes of shortness of breath, 82 (79.61%) reported at least one episode of exacerbation, while 52 subjects (50.49%) were hospitalized for bronchiectasis in the previous 12 months. 23 subjects (22.3%) had anxiety and 32 (31.1%) had depression. Anxiety and depression were significantly associated with indicators of severe disease. The subjects recorded low HRQOL scores across all domains. Psychological distress displayed a significant negative association with all the quality-of-life domains except between anxiety and social interaction. CONCLUSION: Symptoms of depression and anxiety are common among patients with bronchiectasis and these symptoms have a negative impact on HRQOL.

Etiology and Clinical Evaluation of Patients with Bronchiectasis in a Tertiary Hospital in Nigeria.

BACKGROUND: Bronchiectasis is often considered an orphan disease in developed societies. This may not be the case with low-income countries. Currently there is a paucity of data on the pattern and presentation of this condition in Nigeria. OBJECTIVE: This study was undertaken to determine the frequency and pattern of presentation of bronchiectasis in a tertiary healthcare facility in Uyo, South-South, Nigeria. METHODS: We carried out a three-year prospective study of adult patients aged between 15-85 years diagnosed with bronchiectasis in the University of Uyo Teaching Hospital in Uyo, Nigeria between 2016 and 2019. RESULTS: Eighty-two patients were identified from the clinic register. Out of these, 76 were recruited into the study; made up of 44(57.9%) males and 32 (42.1%) females. The average age of the patients was 49.7 ± 14.1 years. Sixteen (21.1%) of the patients were HIV positive. Forty-four (57.9%) patients had previously been treated for pulmonary tuberculosis. Majority of the patients; 72 (94.7%) had chronic productive cough. Sixty-four (84.2%) had at least one episode of exacerbation within the last 12 months while 36(47.4%) had a severe exacerbation requiring hospitalisation. Hospitalisation was associated with several factors with the strongest contributor being the presence of respiratory distress on physical examination (OR 15.4 p= 0.002). CONCLUSION: Bronchiectasis is not an uncommon disease amongst our patients. A previous history of pulmonary tuberculosis is the commonest associated predisposing medical condition. There is a high rate of exacerbation among these patients with respiratory distress as the strongest predictor of hospitalisation.

CONTEXTE: La bronchectasie est souvent considérée comme une maladie orpheline dans les sociétés développées.Ce n'est peut-être pas le cas dans pays à faible revenu. Actuellement, il y a une pénurie de données sur les caractéristiques et la présentation de cette maladie au Nigeria. OBJECTIF: Cette étude a été entreprise pour déterminer la fréquence et le mode de présentation de la bronchectasie dans un établissement de soins tertiaires à Uyo, dans le sud-sud du Nigeria. MÉTHODES: Nous avons mené une étude prospective sur trois ans auprès de patients adultes âgés de 15 à 85 ans chez qui on a diagnostiqué une bronchectasie dans l'hôpital universitaire d'Uyo, à Uyo, entre 2016 et 2019. Uyo, au Nigeria, entre 2016 et 2019. RÉSULTATS: Quatre-vingt-deux patients ont été identifiés à partir du registre de la clinique registre. Parmi ceux-ci, 76 ont été recrutés dans l'étude ; composés de 44 (57,9 %) hommes et 32 (42,1 %) femmes. L'âge moyen des patients était de 49,7 ± 14,1 ans. Seize (21,1 %) des patients étaient séropositifs. Quarante-quatre (57,9 %) patients avaient déjà été traités pour une tuberculose pulmonaire.La majorité des patients ; 72 (94,7%) avaient une toux productive chronique. Soixante-quatre (84,2 %) ont eu au moins un épisode d'exacerbation au cours des 12 derniers mois, tandis que 36 (47,4 %) ont eu une exacerbation sévère nécessitant une hospitalisation. L'hospitalisation était associée à plusieurs facteurs, le facteur le plus important étant la présence d'une présence d'une détresse respiratoire à l'examen physique (OR 15.4 p= 0.002). CONCLUSION: La bronchectasie n'est pas une maladie rare parmi nos patients. Un antécédent de tuberculose pulmonaire est l'état médical prédisposant le plus fréquent.ll existe un taux élevé d'exacerbation chez ces patients, la détresse respiratoire étant le facteur prédictif le plus fort d'hospitalisation. MOTS CLÉS: Étiologie, Caractéristiques cliniques, Bronchiectasie, Exacerbation, Hospitalisation.

Challenges of Case Management of COVID-19 in University of Uyo Teaching Hospital: A One-Year Experience

BACKGROUND AND OBJECTIVES: Coronavirus disease 2019 (COVID-19) is a global pandemic. Older people and those with poorly controlled co-morbidities have higher risk of mortality. This study was conducted to highlight the clinical features, challenges of management and outcome for the patients we have seen in our centre over the past one year. METHODS: This was a retrospective cross-sectional study involving all patients admitted in the COVID-19 Isolation unit of University of Uyo Teaching Hospital (UUTH) from June, 2020­May, 2021. Clinical and laboratory information were obtained from the patient case notes. Ethical clearance for the conduct of the study was obtained from the Ethics committee, UUTH, Uyo. Data was analysed with STATA version 13. RESULTS: Thirty-three (37.9%) patients were COVID-19 PCR positive. The mean ± SD age of COVID-19 PCR positive patients was 57.3 ± 13.4 years with majority (69.7%) being above 50 years. There was a male preponderance (75%). Eleven (34.4%) patients died while 21(65.6%) were discharged. The highest co-morbidity associated with COVID-19 mortality was diabetes mellitus (7 out of 11; 63.6%). There was a poor uptake of supportive investigations for the management of COVID-19 patients. A raised body temperature (P=0.0006), a low SPO2(0.00004), high respiratory rate (0.0009) on admission and shorter duration of admission (0.0002), were associated with mortality. CONCLUSION: The presence of co-morbidities, fever, low SPO2 and high respiratory rates on admission are associated with increased mortality from COVID-19 disease. A paucity of supportive investigations was a major challenge to COVID-19 management. We therefore recommend the strengthening of our laboratory capacity.

Adult skin acute stress responses to short-term environmental and internal aggression from exposome factors.

Exposome factors that lead to stressed skin can be defined as any disturbance to homeostasis from environmental (meteorological factors, solar radiation, pollution or tobacco smoke) and/or internal exposure (unhealthy diet, hormonal variations, lack of sleep, psychosocial stress). The clinical and biological impact of chronic exposome effects on skin functions has been extensively reviewed, whereas there is a paucity of information on the impact of short-term acute exposure. Acute stress, which would typically last minutes to hours (and generally no more than a week), provokes a transient but robust neuroendocrine-immune and tissue remodelling response in the skin and can alter the skin barrier. Firstly, we provide an overview of the biological effects of various acute stressors on six key skin functions, namely the skin physical barrier, pigmentation, defences (antioxidant, immune cell-mediated, microbial and microbiome maintenance), structure (extracellular matrix and appendages), neuroendocrine and thermoregulation functions. Secondly, we describe the biological and clinical effects on adult skin from individual exposome factors that elicit an acute stress response and their consequences in skin health maintenance. Clinical manifestations of acutely stressed skin may include dry skin that might accentuate fine lines, oily skin, sensitive skin, pruritus, erythema, pale skin, sweating, oedema and flares of inflammatory skin conditions such as acne, rosacea, atopic dermatitis, pigmentation disorders and skin superinfection such as viral reactivation. Acute stresses can also induce scalp sensitivity, telogen effluvium and worsen alopecia.

Monofunctionalized Gold Nanoparticles: Fabrication and Applications.

An overview of various approaches to synthesize gold nanoparticles (AuNPs) bearing one single chemically addressable unit and their diverse fields of application is presented. This comprehensive review not only describes the strategies pursued to obtain monofunctionalized AuNPs, but also reports their behavior as 'massive' molecules in wet chemical protocols and the scope of their applications. The latter reaches from site-specific labels in biomolecules over mechanical barriers in superstructures to building blocks in hybrid nano-architectures. The complementing physical properties of AuNPs combined with precise chemical control of their attachment makes these objects promising building blocks for numerous proof-of-concept experiments and applications.

Edemas of the face and lymphoscintigraphic examination.

Facial edemas not secondary to surgery and/or radiotherapy for head and neck cancer are relatively uncommon. Our aim is to report a retrospective analysis of the lymphoscintigraphic and SPECT-CT investigations obtained in patients with such facial edema. Retrospective review of exams (planar imagings in all and with SPECT-CT in 5) obtained after the subcutaneous injection of 99mTc HSA Nanosized colloids between the eyebrows in five men and seven women. Four main lymphatic pathways were identified on sequential planar imagings: para-nasal left and right and supra- ocular left and right. For eleven patients, the absence of visualization of lymphatic drainage and/or their delayed appearance correlated well with the localisation of the edematous areas. In two patients with post-traumatic and post- surgical edemas, SPECT-CT showed one deep left sided cervical lymph node (LN) in front of the first cervical vertebra. This lymphoscintigraphic approach represents a simple and valuable way to assess the lymphatic drainage pathways of the face and to establish the diagnosis of facial lymphedema.

The outcome of conservative treatment of fifth metatarsal diaphyseal fractures.

INTRODUCTION: The fifth metatarsal diaphyseal fracture is a common fracture. However, clear consensus about the treatment is lacking. Unlike the avulsion fracture or Jones' fracture, literature available on the treatment and long-term outcome of the diaphyseal fracture is scarce.The purpose of this study is to demonstrate a substantial number of conservatively treated patients with persistent pain and to evaluate metatarsal shortening and displacement within this group. METHODS: In this retrospective study, 106 patients who had experienced a fifth metatarsal diaphyseal fracture were included and evaluated. The minimum follow-up period was three months. FAAM, AOFAS and NRS scores were used as outcome measurements for function and pain. Length and displacement were analysed on plain X-rays. RESULTS: At least 11% of the patients who received conservative treatment for their fifth metatarsal diaphyseal fracture had persistent pain at least 3 months after initiation of conservative treatment. No relationship has been found between the length of the fifth metatarsal and the FAAM (r( Petrisor et al., 2006) 2 = 0,051), AOFAS (r( Petrisor et al., 2006) 2 = 0,009) and NRS (r( Petrisor et al., 2006) 2 = 0,001). Furthermore, there was no association between patients with a shorter fifth metatarsal and FAAM, AOFAS, NRS, displacement and BMI. DISCUSSION AND CONCLUSION: The finding of persistent pain in at least 11% of all patients at long-term follow-up confirms our hypothesis on long-term symptoms. However, the results suggest that these persistent symptoms are not related to metatarsal shortening or displacement.

Identification of IgG1 isotype phosphorylcholine antibodies for the treatment of inflammatory cardiovascular diseases.

BACKGROUND: Phosphorylcholine (PC) is an important pro-inflammatory damage-associated molecular pattern. Previous data have shown that natural IgM anti-PC protects against cardiovascular disease. We aimed to develop a monoclonal PC IgG antibody with anti-inflammatory and anti-atherosclerotic properties. METHODS: Using various techniques PC antibodies were validated and optimized. In vivo testing was performed in a femoral artery cuff model in ApoE3*Leiden mice. Safety studies are performed in rats and cynomolgus monkeys. RESULTS: A chimeric anti-PC (PC-mAb(T15), consisting of a human IgG1 Fc and a mouse T15/E06 Fab) was produced, and this was shown to bind specifically to epitopes in human atherosclerotic tissues. The cuff model results in rapid induction of inflammatory genes and altered expression of genes associated with ER stress and choline metabolism in the lesions. Treatment with PC-mAb(T15) reduced accelerated atherosclerosis via reduced expression of endoplasmic reticulum stress markers and CCL2 production. Recombinant anti-PC Fab fragments were identified by phage display and cloned into fully human IgG1 backbones creating a human monoclonal IgG1 anti-PC (PC-mAbs) that specifically bind PC, apoptotic cells and oxLDL. Based on preventing macrophage oxLDL uptake and CCL2 production, four monoclonal PC-mAbs were selected, which to various extent reduced vascular inflammation and lesion development. Additional optimization and validation of two PC-mAb antibodies resulted in selection of PC-mAb X19-A05, which inhibited accelerated atherosclerosis. Clinical grade production of this antibody (ATH3G10) significantly attenuated vascular inflammation and accelerated atherosclerosis and was tolerated in safety studies in rats and cynomolgus monkeys. CONCLUSIONS: Chimeric anti-PCs can prevent accelerated atherosclerosis by inhibiting vascular inflammation directly and through reduced macrophage oxLDL uptake resulting in decreased lesions. PC-mAb represents a novel strategy for cardiovascular disease prevention.

Increased case-finding and uptake of direct-acting antiviral treatment essential for micro-elimination of hepatitis C among people living with HIV: a national record linkage study.

OBJECTIVES: Micro-elimination of hepatitis C virus (HCV) in people living with HIV (PLHIV) and co-infected with HCV has been proposed as a key contribution to the overall goal of HCV elimination. While other studies have examined micro-elimination in HIV-treated cohorts, few have considered HCV micro-elimination among those not treated for HIV or at a national level. METHODS: Through data linkage of national and sentinel surveillance data, we examined the extent of HCV testing, diagnosis and treatment among a cohort of PLHIV in Scotland identified through the national database of HIV-diagnosed individuals, up to the end of 2017. RESULTS: Of 5018 PLHIV, an estimated 797 (15%) had never been tested for HCV and 70 (9%) of these had undiagnosed chronic HCV. The odds of never having been tested for HCV were the highest in those not on HIV treatment [adjusted odds ratio (aOR) = 7.21, 95% confidence interval (CI): 5.15-10.10). Overall HCV antibody positivity was 11%, and it was at its highest among people who inject drugs (49%). Most of those with chronic HCV (91%) had attended an HCV treatment clinic but only half had been successfully treated (54% for those on HIV treatment, 12% for those not) by the end of 2017. The odds of never having been treated for HCV were the highest in those not on HIV treatment (aOR = 3.60, 95% CI: 1.59-8.15). CONCLUSIONS: Our data demonstrate that micro-elimination of HCV in PLHIV is achievable but progress will require increased effort to engage and treat those co-infected, including those not being treated for their HIV.

Absence of Low-Energy Shape Coexistence in

The ^{80}Ge structure was investigated in a high-statistics ß-decay experiment of ^{80}Ga using the GRIFFIN spectrometer at TRIUMF-ISAC through γ, ß-e, e-γ, and γ-γ spectroscopy. No evidence was found for the recently reported 0_{2}^{+} 639-keV level suggested as evidence for low-energy shape coexistence in ^{80}Ge. Large-scale shell model calculations performed in ^{78,80,82}Ge place the 0_{2}^{+} level in ^{80}Ge at 2 MeV. The new experimental evidence combined with shell model predictions indicate that low-energy shape coexistence is not present in ^{80}Ge.

ΔK=0 M1 Excitation Strength of the Well-Deformed Nucleus

The size of a ΔK=0 M1 excitation strength has been determined for the first time in a predominantly axially deformed even-even nucleus. It has been obtained from the observation of a rare K-mixing situation between two close-lying J^{π}=1^{+} states of the nucleus ^{164}Dy with components characterized by intrinsic projection quantum numbers K=0 and K=1. Nuclear resonance fluorescence induced by quasimonochromatic linearly polarized γ-ray beams provided evidence for K mixing of the 1^{+} states at 3159.1(3) and 3173.6(3) keV in excitation energy from their γ-decay branching ratios into the ground-state band. The ΔK=0 transition strength of B(M1;0_{1}^{+}→1_{K=0}^{+})=0.008(1)µ_{N}^{2} was inferred from a mixing analysis of their M1 transition rates into the ground-state band. It is in agreement with predictions from the quasiparticle phonon nuclear model. This determination represents first experimental information on the M1 excitation strength of a nuclear quantum state with a negative R-symmetry quantum number.

Quality of life and costs of patients prior to colorectal surgery.

Objective: To assess the quality of life and societal costs of patients prior to colorectal surgery in the Netherlands.Methods: This study is embedded in a previous randomized controlled trial (SANICS II). The quality of life was measured using EQ-5D-5L questionnaires. The iMTA medical consumption questionnaire (iMCQ) and the iMTA productivity costs questionnaire (iPCQ) were used to identify and measure healthcare and productivity costs. Subgroup analyses were performed based on age and gender.Results: A total of 178 patients were included in the cost analysis and a total of 161 patients in the quality of life analysis. The three-month mean societal cost per patient amounted to €3,211 of which €1,459 was due to productivity losses. The mean utility was 0.88 per patient. Gender was an important predictor in quality of life with men scoring significantly higher than women (0.92 versus 0.82) at p < 0.0001.Conclusion: Colorectal cancer represents a high economic burden in the Netherlands. Further research with repeated cost and quality of life measurements would be needed to explore the change over time and the effects of surgery.

A qualitative study of the acceptability of cognitive bias modification for paranoia (CBM-pa) in patients with psychosis.

BACKGROUND: Cognitive Bias Modification (CBM) has been used successfully as a computer-based intervention in disorders such as anxiety. However, CBM to modify interpretations of ambiguous information relevant to paranoia has not yet been tested. We conducted a qualitative investigation of a novel intervention called CBM for paranoia (CBM-pa) to examine its acceptability in patients with psychosis. METHODS: Eight participants with psychosis who completed CBM-pa were identified by purposive sampling and invited for a semi-structured interview to explore the facilitators and barriers to participation, optimum form of delivery, perceived usefulness of CBM-pa and their opinions on applying CBM-pa as a computerised intervention. The interviews were transcribed and analysed using thematic analysis by researchers working in collaboration with service users. RESULTS: Themes emerged relating to participants' perception about delivery, engagement, programme understanding, factors influencing experience, perceived impact and application of CBM-pa. CBM-pa was regarded as easy, straightforward and enjoyable. It was well-accepted among those we interviewed, who understood the procedure as a psychological intervention. Patients reported that it increased their capacity for adopting alternative interpretations of emotionally ambiguous scenarios. Although participants all agreed on the test-like nature of the current CBM-pa format, they considered that taking part in sessions had improved their overall wellbeing. Most of them valued the computer-based interface of CBM-pa but favoured the idea of combining CBM-pa with some form of human interaction. CONCLUSIONS: CBM-pa is an acceptable intervention that was well-received by our sample of patients with paranoia. The current findings reflect positively on the acceptability and experience of CBM-pa in the target population. Patient opinion supports further development and testing of CBM-pa as a possible adjunct treatment for paranoia. TRIAL REGISTRATION: Current Controlled Trials ISRCTN: 90749868 . Retrospectively registered on 12 May 2016.

Effect of microchannel structure and fluid properties on non-inertial particle migration.

In this work, we investigate the influence of channel structure and fluid rheology on non-inertial migration of non-Brownian polystyrene beads. Particle migration in this regime can be found in biomedical, chemical, environmental and geological applications. However, the effect of fluid rheology on particle migration in porous media remains to be clearly understood. Here, we isolate the effects of elasticity and shear thinning by comparing a Newtonian fluid, a purely elastic (Boger) fluid, and a shear-thinning elastic fluid. To mimic the complexity of geometries in real-world application, a random porous structure is created through a disordered arrangement of cylindrical pillars in the microchannel. Experiments are repeated in an empty channel and in channels with an ordered arrangement of pillars, and the similarities and differences in the observed particle focusing are analyzed. It is found that elasticity drives the particles away from the channel walls in an empty microchannel. Notably, particle focusing is unaffected by curved streamlines in an ordered porous microchannel and particles stay away from pillars in elastic fluids. Shear-thinning is found to reduce the effect of focusing and a broader region of particle concentration is observed. It is also noteworthy that the rheological characteristics of the fluid are not important for the particle distribution in a randomly arranged pillared microchannel and particles have a uniform distribution for all suspending fluids. Moreover, discussion on the current discrepancy in the literature about the equilibrium positions of the particles in a channel is extended by analyzing the results obtained in the current experiments.

Elaboration and validation of the method for the quantification of the emetic toxin of Bacillus cereus as described in EN-ISO 18465 - Microbiology of the food chain - Quantitative determination of emetic toxin (cereulide) using LC-MS/MS.

A method for the quantification of the Bacillus cereus emetic toxin (cereulide) was developed and validated. The method principle is based on LC-MS as this is the most sensitive and specific method for cereulide. Therefore the study design is different from the microbiological methods validated under this mandate. As the method had to be developed a two stage validation study approach was used. The first stage (pre-study) focussed on the method applicability and the experience of the laboratories with the method. Based on the outcome of the pre-study and comments received during voting at CEN and ISO level a final method was agreed to be used for the second stage the (final) validation of the method. In the final (validation) study samples of cooked rice (both artificially contaminated with cereulide or contaminated with B. cereus for production of cereulide in the rice) and 6 other food matrices (fried rice dish, cream pastry with chocolate, hotdog sausage, mini pancakes, vanilla custard and infant formula) were used. All these samples were spiked by the participating laboratories using standard solutions of cereulide supplied by the organising laboratory. The results of the study indicate that the method is fit for purpose. Repeatability values were obtained of 0.6 µg/kg at low level spike (ca. 5 µg/kg) and 7 to 9.6 µg/kg at high level spike (ca. 75 µg/kg). Reproducibility at low spike level ranged from 0.6 to 0.9 µg/kg and from 8.7 to 14.5 µg/kg at high spike level. Recovery from the spiked samples ranged between 96.5% for mini-pancakes to 99.3% for fries rice dish.

The impact of laboratory closing times on delay of adequate therapy in blood stream infections.

BACKGROUND: Patients with bloodstream infections need early adequate antimicrobial treatment to reduce mortality. This raises the question of timing and logistics. How important is the time of day when a culture is flagged positive to the processing of blood cultures and optimisation of antimicrobial therapy? METHODS: We performed a retrospective study assessing the time delay of a positive blood culture result during and after office hours and its impact on adequate antimicrobial therapy. Process duration from the moment of culture positivity to Gram stain completion was compared at different timepoints during the day in a medium-sized hospital with an offsite microbiological laboratory. RESULTS: Ninety-four patients with positive, noncontaminated blood cultures were included. Sixty-six patients (70%) received adequate empirical therapy; this increased to 76 cases (82%) and to 88 cases (95%) after analysis of Gram stain results and complete determination, respectively (p < 0.05 for all comparisons). Median duration from culture positivity to Gram stain completion (including offsite culture transport) increased from a median of four to 12 hours if time of cultures turned positive after office hours (p < 0.05), irrespective of the adequacy of empirical coverage. This also resulted in a median 12-hour delay for the complete process from time of culture positivity to administration of the antimicrobial drug (p < 0.05). CONCLUSION: Processing blood cultures after office hours is often deferred, which can lead to a delay in adequate antimicrobial therapy for patients with bloodstream infections.

Viscoelastic effects on residual oil distribution in flows through pillared microchannels.

HYPOTHESIS: Multiphase flow through porous media is important in a number of industrial, natural and biological processes. One application is enhanced oil recovery (EOR), where a resident oil phase is displaced by a Newtonian or polymeric fluid. In EOR, the two-phase immiscible displacement through heterogonous porous media is usually governed by competing viscous and capillary forces, expressed through a Capillary number Ca, and viscosity ratio of the displacing and displaced fluid. However, when viscoelastic displacement fluids are used, elastic forces in the displacement fluid also become significant. It is hypothesized that elastic instabilities are responsible for enhanced oil recovery through an elastic microsweep mechanism. EXPERIMENTS: In this work, we use a simplified geometry in the form of a pillared microchannel. We analyze the trapped residual oil size distribution after displacement by a Newtonian fluid, a nearly inelastic shear thinning fluid, and viscoelastic polymers and surfactant solutions. FINDINGS: We find that viscoelastic polymers and surfactant solutions can displace more oil compared to Newtonian fluids and nearly inelastic shear thinning polymers at similar Ca numbers. Beyond a critical Ca number, the size of residual oil blobs decreases significantly for viscoelastic fluids. This critical Ca number directly corresponds to flow rates where elastic instabilities occur in single phase flow, suggesting a close link between enhancement of oil recovery and appearance of elastic instabilities.