1,070 research outputs found
A gain-coefficient switched Alexandrite laser
We report on a gain-coefficient switched Alexandrite laser. An electro-optic
modulator is used to switch between high and low gain states by making use of
the polarization dependent gain of Alexandrite. In gain-coefficient switched
mode, the laser produces 85 ns pulses with a pulse energy of 240 mJ at a
repetition rate of 5 Hz.Comment: 8 pages, 5 figure
Mapping individual electromagnetic field components inside a photonic crystal
We present a method to map the absolute electromagnetic field strength inside
photonic crystals. We apply the method to map the electric field component Ez
of a two-dimensional photonic crystal slab at microwave frequencies. The slab
is placed between two mirrors to select Bloch standing waves and a
subwavelength spherical scatterer is scanned inside the resulting resonator.
The resonant Bloch frequencies shift depending on the electric field at the
position of the scatterer. To map the electric field component Ez we measure
the frequency shift in the reflection and transmission spectrum of the slab
versus the scatterer position. Very good agreement is found between
measurements and calculations without any adjustable parameters.Comment: 12 pages, 7 figure
Selective Aerobic Oxidation of Lactate to Pyruvate Catalyzed by VanadiumâNitrogenâDoped Carbon Nanosheets
Robust zero-energy modes in an electronic higher-order topological insulator: the dimerized Kagome lattice
Quantum simulators are an essential tool for understanding complex quantum
materials. Platforms based on ultracold atoms in optical lattices and photonic
devices led the field so far, but electronic quantum simulators are proving to
be equally relevant. Simulating topological states of matter is one of the holy
grails in the field. Here, we experimentally realize a higher-order electronic
topological insulator (HOTI). Specifically, we create a dimerized Kagome
lattice by manipulating carbon-monoxide (CO) molecules on a Cu(111) surface
using a scanning tunneling microscope (STM). We engineer alternating weak and
strong bonds to show that a topological state emerges at the corner of the
non-trivial configuration, while it is absent in the trivial one. Contrarily to
conventional topological insulators (TIs), the topological state has two
dimensions less than the bulk, denoting a HOTI. The corner mode is protected by
a generalized chiral symmetry, which leads to a particular robustness against
perturbations. Our versatile approach to quantum simulation with artificial
lattices holds promises of revealing unexpected quantum phases of matter
Vesicular Tubular Clusters between the ER and Golgi Mediate Concentration of Soluble Secretory Proteins by Exclusion from COPI-Coated Vesicles
AbstractWe have determined the concentrations of the secretory proteins amylase and chymotrypsinogen and the membrane proteins KDELr and rBet1 in COPII- and COPI-coated pre-Golgi compartments of pancreatic cells by quantitative immunoelectron microscopy. COPII was confined to ER membrane buds and adjacent vesicles. COPI occurred on vesicular tubular clusters (VTCs), Golgi cisternae, the trans-Golgi network, and immature secretory granules. Both secretory proteins exhibited a first, significant concentration step in noncoated segments of VTC tubules and were excluded from COPI-coated tips. By contrast, KDELr and rBet1 showed a first, significant concentration in COPII-coated ER buds and vesicles and were prominently present in COPI-coated tips of VTC tubules. These data suggest an important role of VTCs in soluble cargo concentration by exclusion from COPI-coated domains
Negative Feelings Exacerbate Hostile Attributions of Intent In Highly Aggressive Boys [IF: 1.714]
Precisie rechtgeleiding werktuig met RTK GPS : een onderzoek naar verschillende stuursystemen op basis van nauwkeurige GPS systemen
Porojectnummer 325003150
Thrombin Stimulates Glucose Transport in Human Platelets via the Translocation of the Glucose Transporter GLUT-3 from α-Granules to the Cell Surface
Increased energy metabolism in the circulating blood platelet plays an essential role in platelet plug
formation and clot retraction. This increased energy
consumption is mainly due to enhanced anaerobic consumption of glucose via the glycolytic pathway. The aim
of the present study was to determine the role of glucose transport as a potential rate-limiting step for human platelet glucose metabolism. We measured in isolated platelet preparations the effect of thrombin and
ADP activation, on glucose transport (2-deoxyglucose
uptake), and the cellular distribution of the platelet glucose transporter (GLUT), GLUT-3. Thrombin (0.5
U/ml) caused a pronounced shape change and secretion
of most α-granules within 10 min. During that time glucose transport increased approximately threefold, concomitant with a similar increase in expression of
GLUT-3 on the plasma membrane as observed by immunocytochemistry. A major shift in GLUT-3 labeling
was observed from the α-granule membranes in resting
platelets to the plasma membrane after thrombin treatment. ADP induced shape change but no significant
α-granule secretion. Accordingly, ADP-treated platelets showed no increased glucose transport and no increased GLUT-3 labeling on the plasma membrane.
These studies suggest that, in human blood platelets, increased energy metabolism may be precisely coupled to
the platelet activation response by means of the translocation of GLUT-3 by regulated secretion of α-granules. Observations in megakaryocytes and platelets
freshly fixed from blood confirmed the predominant
GLUT-3 localization in α-granules in the isolated cells,
except that even less GLUT-3 is present at the plasma
membrane in the circulating cells (âŒ15%), indicating
that glucose uptake may be upregulated five to six
times during in vivo activation of platelets
[An implant-supported overdenture in an edentulous upper jaw].
An implant-supported overdenture is a good alternative treatment to a conventional denture for patients with complaints about the retention and stability of their removable complete denture. These complaints more often have to do with the mandibular than the maxillary denture. Implant-supported overdentures offer better results in the mandible than in the maxilla. In cases of insujficient bone volume in the maxilla for inserting implants, maxillary sinus floor elevation using an autogenous bone graft from the oral cavity or the iliac crest may be carried out. Treatment of the edentulous maxilla by inserting 6 implants followed by manufacturing a bar-clip mesostructure and an implant-supported overdenture is the most successful, followed closely by the treatment option of inserting 4 implants and fabricating a similar mesostructure and overdenture. Aftercare by routine preventive examinations is required.</p
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