Acoustofluidic particle steering

Steering micro-objects using acoustic radiation forces is challenging for several reasons: Resonators tend to create fixed force distributions that depend primarily on device geometry, and even when using switching schemes, the forces are hard to predict a priori. In this paper an active approach is developed that measures forces from a range of acoustic resonances during manipulation using a computer controlled feedback loop based in matlab, with a microscope camera for particle imaging. The arrangement uses a planar resonator where the axial radiation force is used to hold particles within a levitation plane. Manipulation is achieved by summing the levitation frequency with an algorithmically chosen second resonance frequency, which creates lateral forces derived from gradients in the kinetic energy density of the acoustic field. Apart from identifying likely resonances, the system does not require a priori knowledge of the structure of the acoustic force field created by each resonance. Manipulation of 10 μm microbeads is demonstrated over 100 s μm. Manipulation times are of order 10 s for paths of 200 μm length. The microfluidic device used in this work is a rectangular glass capillary with a 6 mm wide and 300 μm high fluid chamber.</p

CEA, CYFRA 21-1, NSE, and ProGRP in the diagnosis of lung cancer: a multivariate approach

We retrospectively studied the single and combined diagnostic value of carcinoembryonic antigen (CEA), cytokeratin fragment 19 (CYFRA 21-1), neuron specific enolase (NSE) and pro-gastrin-releasing peptide (ProGRP), which were routinely analysed in patients with lung tumours of unknown origin at the time of admission to hospital. Inclusion criteria were the determination of CEA (AxSYM/Abbott), CYFRA 21-1 (ElecSys/Roche) and NSE (Kryptor/Brahms). We examined 1747 patients, where 1325 suffered from lung cancer (LC; small cell lung cancer, SCLC: n=194; non-small cell lung cancer, NSCLC: n = 1015; others: n = 116), 318 from benign lung diseases and 104 from lung metastases due to another primary malignancy. As ProGRP (ELISA ALSI/IBL) became available only recently, there are less data points of this marker. In total, 99.8% of LC patients released at least one of the four biomarkers (defined as values exceeding the median of healthy controls), and for the discrimination between benign disease (BID) and malignant lung disease each marker reached 100% tumour specificity at high levels (CEA: 20 ng/mL; CYFRA 21-1: 40 ng/mL; NSE: 45 ng/mL; ProGRP: 250 pg/mL). At a specificity of &gt; 99%, ProGRP reached the highest diagnostic efficacy for SCLC with 57% true positive results, CEA had the highest capacity (17%) to detect malignant lung tumours in general and adenocarcinomas of the lung with 29%. CYFRA 21-1 was dominant for squamous cell carcinomas (12%). Combining the four markers leads with the prerequisite of high specificity (&gt; 99%) to 50% true positives for malignant lung tumours, 44% for NSCLC, 36% for squamous cell carcinomas, 53% for adenocarcinomas, and 78% for SCLC, respectively. In cases of lung tumours of unknown origin, the combined use of CEA, CYFRA 21-1, NSE and ProGRP is useful for the differentiation between benign and primary or secondary malignant disease and suggests the assignment to histological subtypes

Psoriasis—An Immunological Disease

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111129/1/jde02714.pd

Acoustic trapping in bubble-bounded micro-cavities

We present a method for controllably producing longitudinal acoustic trapping sites inside microfluidic channels. Air bubbles are injected into a micro-capillary to create bubble-bounded ‘micro-cavities’. A cavity mode is formed that shows controlled longitudinal acoustic trapping between the two air/water interfaces along with the levitation to the centre of the channel that one would expect from a lower order lateral mode. 7 µm and 10 µm microspheres are trapped at the discrete acoustic trapping sites in these micro-cavities. We show this for several lengths of micro-cavity

Bryn Hammarstrom, Sr. Interview, August 4, 1989

Bryn Hammarstrom describes smokejumper training at Seeley Lake, Montana, where he was sent after applying for conscientious objector status during World War Two. He talks about his smokejumper duties, which included repairing and packing parachutes. He recalls specific jumps including one in Yellowstone Park. He recalls some specific incidents during his Civilian Public Service [CPS] years including a truck accident, smokejumper training at Nine Mile, Montana, and assisting with a bridge removal in St. Regis, Montana. This is not an audio interview. Hammarstrom responds in writing to a series of questions sent to him by Roxanne Farwell.https://scholarworks.umt.edu/civilianpublicservicesmokejumpers_oralhistory/1019/thumbnail.jp

Hormone affinity and fibril formation of piscine transthyretin: the role of the N-terminal

Transthyretin (TTR) transports thyroid hormones (THs), thyroxine (T4) and triiodothyronine (T3) in the blood of vertebrates. TH-binding sites are highly conserved in vertebrate TTR however, piscine TTR has a longer N-terminus which is thought to influence TH-binding affinity and may influence TTR stability. We produced recombinant wild-type sea bream TTR (sbTTRWT) plus two mutants in which six (sbTTRM6) and twelve (sbTTRM12) N-terminal residues were removed. Ligandbinding studies revealed similar affinities for T3 (Kd=10.6±1.7nM) and T4 (Kd=9.8±0.97nM) binding to sbTTRWT. Affinity for THs was unaltered in sbTTRM12 but sbTTRM6 had poorer affinity for T4 (Kd=252.3±15.8nM) implying that some residues in the N-terminus can influence T4 binding. sbTTRM6 inhibited acid-mediated fibril formation in vitro as shown by fluorometric measurements using thioflavine-T.In contrast, fibril formation by sbTTRM12 was significant, probably due to decreased stability of the tetramer. Such studies also suggested that sbTTRWT is more resistant to fibril formation than human TTR

Synthetic Peptides: Design, Structure and Biological Function.

The synthesis of a series of polyfunctional Calpha,C alpha-disubstituted glycines is described. The lysine-like amino acid analog, Api, was prepared by regioselective hydrolysis of a triBoced hydantoin, followed by Nalpha-protection to yield the first orthogonally protected ionizable Calpha,Calpha-disubstituted amino acid which is alicyclic. The synthesis of three orthogonally protected tetrafunctional amino acids, Bap, Bglu, and Basp was envisioned by alkylation of the organic synthon ethyl nitroacetate. Subsequent regioselective modification should allow for the isolation of the first tetrafunctional amino acid derivatives suitable for solid-phase synthesis. These amino acids are designed to induce peptide secondary structure by salt-bridge stabilization. A series of peptides, incorporating 80% Calpha,C alpha-disubstituted glycines were synthesized to establish the helix stabilizing effect of amphipathicity in short helices. The peptides were prepared as permutation isomer pairs, Pi-10 & Ipi-10; Ach-10alpha & Ach-10; and Cyh-10 & Ich-10. The peptides within each pair contain the same amino acid content, with different sequences, each designed to preferentially adopt a 310- or alpha-helix. Circular dichroism confirms that amphipathicity is a significant factor in shifting the 310-/alpha-helix equilibrium, notably so in micellar environments. The bioactivity of the aforementioned peptides was established by minimum inhibitory concentrations (MICs) against representative Gram-positive and Gram-negative bacteria. The more hydrophobic peptides showed higher levels of cytotoxicity than the less hydrophobic peptides. In vitro studies using a strain of Brucella abortus expressing Green Fluorescent Protein (GFP) show that all of the peptides exhibit moderate to high selectivity towards the destruction of murine macrophages infected with the intracellular pathogen. The spectroscopic properties of the o-nitrobenzenesulfonyl (oNBS) group have been established to confirm the practical use of this protecting group in solid-phase synthesis. Synthesis of the deprotection product, resulting from treatment of the oNBS-protected amino acid with mercaptoacetic acid/DBU, shows a linear correlation between concentration and absorption at 390 nm. Molar absorptivity, &egr;390 was determined to be 2950 cm-1M-1. This number was verified by solution-phase cleavage of several oNBS-protected Calpha,Calpha-disubstituted amino acids, which were synthesized by a modified Bolin procedure to allow for synthesis under non-aqueous conditions

Preventing Loneliness and Increasing Student Engagement in First-Generation College Students

As higher education institutions work to diversify and expand their student populations, one topic that requires ongoing consideration is retention rates. First-generation college students make up a significant portion of undergraduate classes (Skomsvald, 2015); however, they are also the population least likely to see their degrees to completion (Radunzel, 2021). This suggests there may be barriers keeping these students from collegiate success, which we predicted to be loneliness and a lack of student engagement (Barreto et al., 2021; Peplau & Perlman, 1982). This study investigated several predictors of student engagement via loneliness in first-generation college students. First-generation college students (N = 85; Mage = 30.64) completed an online survey measuring demographics, emotional intelligence, extraversion, neuroticism, community involvement, loneliness, social-self compassion, and higher education student engagement. Loneliness was not a significant mediator in any of the models tested. Future researchers should examine other possible predictors of loneliness and/or student engagement in first-generation students to further understand ways to increase retention rates for such students