Elastometry of deflated capsules elastic moduli from shape and wrinkle analysis

Elastic capsules, prepared from droplets or bubbles attached to a capillary (as in a pendant drop tensiometer), can be deflated by suction through the capillary. We study this deflation and show that a combined analysis of the shape and wrinkling characteristics enables us to determine the elastic properties in situ. Shape contours are analyzed and fitted using shape equations derived from nonlinear membrane-shell theory to give the elastic modulus, Poisson ratio and stress distribution of the membrane. We include wrinkles, which generically form upon deflation, within the shape analysis. Measuring the wavelength of wrinkles and using the calculated stress distribution gives the bending stiffness of the membrane. We illustrate this method on two very different capsule materials: polymerized octadecyltrichlorosilane (OTS) capsules and hydrophobin (HFBII) coated bubbles. Our results are in agreement with the available rheological data. For hydrophobin coated bubbles the method reveals an interesting nonlinear behavior consistent with the hydrophobin molecules having\ud a rigid core surrounded by a softer shell

Variabilitas Suhu Dan Salinitas Di Laut Halmahera

Suhu dan salinitas memiliki peranan penting dalam mencerminkan kondisi massa air dan secara langsung berpengaruh terhadap kondisi biologi dan kimia perairan. Tujuan penelitian ini adalah menganalisis dinamika angin di perairan Laut Halmahera dan mendiskripsikan kondisi suhu dan salinitas permukaan laut (SPL) di Laut Halmahera. Data yang digunakan yaitu data penginderaan jauh Marine Copernicus untuk data Suhu dan salinitas sedangkan data angin dari ECMWF. Pengolahan data menggunakan software ODV untuk mengolah data SPL dan salinitas dari tahun 2016-2020, selanjutnya data angin diolah menggunakan software surfer 16. Laut Halmahera memiliki suhu permukaan laut berkisar antara 26.20 - 31.6°C dimana kondisi maksimum terjadi bulan Mei dan November. Sedangkan salinitas berkisar antara 29.38 - 34.9 psu, dimana kondisi maksimum pada bulan Desember sampai Maret. Dinamika angin di Laut Halmahera mempengaruhi pola sebaran suhu permukaan laut dan salinitas yang ada pada perairan tersebut, dimana kecepatan angin berkisar antara 6.5 - 2.5 m/s

Molecular immunophenotyping of lungs and spleens in naive and vaccinated chickens early after pulmonary avian influenza A (H9N2) virus infection

In a respiratory-infection-model with the avian influenza A H9N2 virus we studied lung and splenic immune reactions in chickens using a recently developed 5K chicken immuno-microarray. Groups of chickens were either mock-immunized (referred to as non-immune), vaccinated with inactivated viral antigen only (immune) or with viral antigen in a water-in-oil (W/O) immunopotentiator (immune potentiated). Three weeks after vaccination all animals were given a respiratory infection. Immune potentiated birds developed inhibitory antiviral antibodies, showed minimal lung histopathology and no detectable viral sequences, while non-immune animals showed microscopic immunopathology and detectable virus. Immune birds, receiving antigen in saline only, showed minimal microscopic histopathology, and intermediate levels of virus detection. These classical features in the different groups were mirrored by overlapping or specific mRNA gene expression profiles in lungs and spleen using microarray analysis. To our knowledge this is the first study demonstrating pneumonia-associated lung pathology of the low pathogenic avian influenza H9N2 virus. Our data provide insights into the molecular interaction of this virus with its natural host when naive or primed by vaccination

THE Pb AND Cd CONCENTRATIONS IN MANGROVE SUBSTRATE OF AMBON BAY

The mangrove ecosystem is one of the potential coastal ecosystems in Ambon Bay waters, most of which are in Inner Ambon Bay.Threats to the mangrove ecosystem in the waters of Ambon Bay are the activities that take place around it. Moreover, several rivers that empty into Ambon Bay cause the entry of debris/waste from land. Previous studies have shown that Pb and Cd have been detected in seawater in Ambon Bay waters, so it is considered important to conduct research on mangrove ecosystem sediments. The purpose of this study was to determine the concentration of heavy metals (Pb and Cd) in sediments in the mangrove ecosystem of Ambon Bay. The sampling points of the sediment in mangrove ecosystems were carried out using purposive sampling method. Sample analysis was carried out at the Environmental Productivity Laboratory of IPB using the Nitric Acid-Perchloric Acid Digestion method. The results showed that the concentration of heavy metal Plumbum (Pb) ranged from 18.25-35.98 mg/kg and Cadmium (Cd) 1.57-2.70 mg/kg. The results showed that the concentration of heavy metal Plumbum (Pb) ranged from 18.25-35.98 mg/kg and Cadmium (Cd) 1.57-2.70 mg/kg. Based on the results of the analysis, it can be said that, although Pb was found in fairly high concentrations, it had not yet exceeded the toxic threshold, while Cd had approached the toxic threshold. Overall, it can be concluded that the sediment has been contaminated with heavy metals Pb and Cd but has not affected the mangrove ecosystem, and is an indication that natural filtration occurs.Salah satu potensi ekosistem pesisir yang cukup luas ada di perairan Teluk Ambon Dalam adalah ekosistem mangrove. Ancaman bagi ekosistem mangrove yang ada di perairan Teluk Ambon adalah aktivitas yang berlangsung di sekitarnya (antropogenik). Adanya beberapa sungai yang bermuara di Teluk Ambon menjadi pendukung masuknya buangan/limbah dari darat. Logam berat Pb dan Cd telah terdeteksi pada air laut di perairan Teluk Ambon, sehingga dianggap penting untuk melakukan penelitian pada sedimen ekosistem mangrove. Tujuan dari penelitian ini adalah untuk mengetahui konsentrasi logam berat (Pb dan Cd) dalam sedimen pada ekosistem mangrove Teluk Ambon. Penentuan titik pengambilan sampel sedimen pada ekosistem mangrove dilakukan dengan menggunakan metode purposive sampling. Analisis sampel dilakukan dengan menggunakan metode Nitric Acid-Perchloric Acid Digestion. Hasil penelitian menunjukkan bahwa konsentrasi logam berat Plumbum (Pb) berkisar antara 18,25-35,98 mg/kg dan Cadmium (Cd) 1,57-2,70 mg/kg. Hasil analisis menunjukkan bahwa, Pb walaupun didapati dalam konsentrasi yang cukup tinggi namun belum melampaui ambang batas toksik, sementara Cd telah mendekati ambang batas toksik. Secara keseluruhan dapat disimpulkan bahwa, sedimen telah terkontaminasi logam berat Pb dan Cd namun belum berpengaruh pada ekosistem mangrove, dan merupakan indikasi bahwa terjadi filtrasi alami. &nbsp

Oxidation of 2'-Deoxyguanosine and 8-Oxo-2'-deoxyguanosine by Dimethyldioxirane

Oxidative damage to DNA can lead to cancer, aging, and neurological disorders. Of the four DNA bases, guanine is the most susceptible to oxidation. To help us further our knowledge of how oxidation contributes to illness and disease, it is important to study the oxidation process and products of 2'-deoxyguanosine (2'-dG). The oxidation product of 2'-dG, 8-oxo-2'-deoxyguanosine (8-oxo-2'-dG), is even more susceptible to oxidation than 2'-dG, and for this reason, it is imperative to study its oxidation products as well. For our study, oxidations of 2'-deoxyguanosine and 8-oxo-2' -deoxyguanosine were conducted with the powerful chemical oxidant dimethyldioxirane (DMDO). Oxidation products were then characterized with the use of HPLC, proton and multidimensional heteronuclear NMR, and electrospray MS in the positive ion mode. Because DMDO reacts selectively, it was expected that oxidation would occur at all types of double bonds, and possibly at NH2 or NH. However, it was found that the major product fraction was formed from epoxidation of the C-4 to C-5 double bond followed by solvolysis. Hence, in the reaction of DMDO with 2'-deoxyguanosine, epoxidation followed by hydrolysis or methanolysis formed 4,5-dihydro-4,5-dihydroxy-2'-deoxyguanosine and 4,5-dihydro-4-hydroxy-5-methoxy-2'-deoxyguanosine respectively. When DMDO reacted with 8-oxo-2'-deoxyguanosine in a solution of water and methanol, epoxidation followed by hydrolysis resulted in the formation of 4,5-dihydro-4,5-dihydroxy-8-oxo-2'-deoxyguanosine and epoxidation followed by methanolysis resulted in the formation of 4,5-dihydro-4-hydroxy-5-methoxy-8-oxo-2'-deoxyguanosine. The latter was further verified by conducting oxidations in perdeuterated methanol. This research concludes that DMDO, which has an oxidation mechanism analogous to the mixed-function oxidases, generates products distinct from those arising from radical chemistry.Master of Science in Public Healt

Harnessing nuclear spin polarization fluctuations in a semiconductor nanowire

Soon after the first measurements of nuclear magnetic resonance (NMR) in a condensed matter system, Bloch predicted the presence of statistical fluctuations proportional to $1/\sqrt{N}$ in the polarization of an ensemble of $N$ spins. First observed by Sleator et al., so-called "spin noise" has recently emerged as a critical ingredient in nanometer-scale magnetic resonance imaging (nanoMRI). This prominence is a direct result of MRI resolution improving to better than 100 nm^3, a size-scale in which statistical spin fluctuations begin to dominate the polarization dynamics. We demonstrate a technique that creates spin order in nanometer-scale ensembles of nuclear spins by harnessing these fluctuations to produce polarizations both larger and narrower than the natural thermal distribution. We focus on ensembles containing ~10^6 phosphorus and hydrogen spins associated with single InP and GaP nanowires (NWs) and their hydrogen-containing adsorbate layers. We monitor, control, and capture fluctuations in the ensemble's spin polarization in real-time and store them for extended periods. This selective capture of large polarization fluctuations may provide a route for enhancing the weak magnetic signals produced by nanometer-scale volumes of nuclear spins. The scheme may also prove useful for initializing the nuclear hyperfine field of electron spin qubits in the solid-state.Comment: 18 pages, 5 figure

Urokinase-type plasminogen activator supports liver repair independent of its cellular receptor

BACKGROUND: The urokinase-type (uPA) and tissue-type (tPA) plasminogen activators regulate liver matrix remodelling through the conversion of plasminogen (Plg) to the active protease plasmin. Based on the efficient activation of plasminogen when uPA is bound to its receptor (uPAR) and on the role of uPA in plasmin-mediated liver repair, we hypothesized that uPA requires uPAR for efficient liver repair. METHODS: To test this hypothesis, we administered one dose of carbon tetrachloride (CCl(4)) to mice with single or combined deficiencies of uPA, uPAR and tPA, and examined hepatic morphology, cellular proliferation, fibrin clearance, and hepatic proteolysis 2–14 days later. RESULTS: Absence of uPAR alone or the combined absence of uPAR and tPA had no impact on the resolution of centrilobular injury, but the loss of receptor-free uPA significantly impaired the clearance of necrotic hepatocytes up to 14 days after CCl(4). In response to the injury, hepatocyte proliferation was normal in mice of all genotypes, except for uPAR-deficient (uPAR°) mice, which had a reproducible but mild decrease by 33% at day 2, with an appropriate restoration of liver mass by 7 days similar to experimental controls. Immunostaining and zymographic analysis demonstrated that uPA alone promoted fibrin clearance from centrilobular regions and efficiently activated plasminogen. CONCLUSION: uPA activates plasminogen and promotes liver matrix proteolysis during repair via a process that neither requires its receptor uPAR nor requires a contribution from its functional counterpart tPA

Lateral Compartment Contact Pressures Do Not Increase After Lateral Extra-articular Tenodesis and Subsequent Subtotal Meniscectomy

© The Author(s) 2019. Background: Modified Lemaire lateral extra-articular tenodesis (LET) has been proposed as a method of addressing persistent anterolateral rotatory laxity after anterior cruciate ligament (ACL) reconstruction (ACLR). However, concerns remain regarding the potential for increasing lateral compartment contact pressures. Purpose: To investigate changes in tibiofemoral joint contact pressures after isolated ACLR and combined ACLR plus LET with varying states of a lateral meniscal injury. Study Design: Controlled laboratory study. Methods: Eight fresh-frozen cadaveric knee specimens (mean age, 60.0 ± 3.4 years) were utilized for this study, with specimens potted and loaded on a materials testing machine. A pressure sensor was inserted into the lateral compartment of the tibiofemoral joint, and specimens were loaded at 0°, 30°, 60°, and 90° of flexion in the following states: (1) baseline (ACL- and anterolateral ligament–deficient), (2) ACLR, (3) ACLR with LET, (4) partial meniscectomy (removal of 50% of the posterior third of the lateral meniscus), (5) subtotal meniscectomy (removal of 100% of the posterior third of the lateral meniscus), and (6) LET release (LETR). Mean contact pressure, peak pressure, and center of pressure were analyzed using 1-way repeated-measures analysis of variance. Results: Across all flexion angles, there was no statistically significant increase in the mean contact pressure or peak pressure after ACLR plus LET with and without lateral meniscectomy compared with isolated ACLR. There was a significant reduction in the mean contact pressure, from baseline, after subtotal meniscectomy (69.72% ± 19.27% baseline; P =.04) and LETR (65.81% ± 13.40% baseline; P =.003) at 0° and after the addition of LET to ACLR at 30° (61.20% ± 23.08% baseline; P =.031). The center of pressure was observed to be more anterior after partial (0°, 30°) and subtotal (0°, 60°) meniscectomy and LETR (0°, 30°, 60°). Conclusion: Under the loading conditions of this study, LET did not significantly alter lateral compartment contact pressures when performed in conjunction with ACLR in the setting of an intact or posterior horn–deficient lateral meniscus. Clinical Relevance: This study should provide surgeons with the confidence that it is safe to perform LET in this manner in conjunction with ACLR without altering lateral compartment pressures, regardless of the status of the lateral meniscus