3,844 research outputs found
A dynamic model of UVR8 photoreceptor signaling in UV-B acclimated Arabidopsis
The photoreceptor UVR8 mediates numerous photomorphogenic responses of plants to UVâB wavelengths by regulating transcription. Studies with purified UVR8 and seedlings not previously exposed to UVâB have generated a model for UVR8 action in which dimeric UVR8 rapidly monomerises in response to UVâB exposure to initiate signaling. However, the mechanism of UVR8 action in UVâBâacclimated plants growing under photoperiodic conditions, where UVR8 exists in a dimer/monomer photoâequilibrium, is poorly understood.
We examined UVR8 dimer/monomer status, gene expression responses, amounts of key UVR8 signaling proteins and their interactions with UVR8 in UVâBâacclimated Arabidopsis.
We show that in UVâBâacclimated plants UVR8 can mediate a response to a 15âfold increase in UVâB without any increase in abundance of UVR8 monomer. Following transfer to elevated UVâB, monomers show increased interaction with both COP1, to initiate signaling, and RUP2, to maintain the photoâequilibrium when the dimer/monomer cycling rate increases. Native RUP1 is present in low abundance compared with RUP2.
We present a model for UVR8 action in UVâBâacclimated plants growing in photoperiodic conditions that incorporates dimer and monomer photoreception, dimer/monomer cycling, abundance of native COP1 and RUP proteins, and interactions of the monomer population with COP1, RUP2 and potentially other proteins
Quantum Nonlinear Effect in Dissipatively Coupled Optomechanical System
A full-quantum approach is used to study quantum nonlinear properties of a
compound Michelson-Sagnac interferometer optomechanical system. The effective
Hamiltonian shows that both dissipative and dispersive couplings possess
imaginary- and real-Kerr nonlinearities. And unexpectedly, the nonlinearities
caused by the dissipative coupling have non-Hermitian Hamiltonian-like
properties. It can protect the quantum nature of the dispersive coupling beyond
the traditional dissipation of the system. This protection mechanism allows the
system to exhibit strong quantum nonlinear effects in the parameter region of
the hyperbolic function . Moreover, we can obtain
strong anti-bunching effects whether in strong or weak coupling regimes with
the help of the dispersive and dissipative couplings jointly. It may provide a
new perspective to experimentally realize and study the strong quantum
nonlinear effects
Quantized Feedback Control for Networked Control Systems Under Communication Constraints
This paper investigates the feedback stabilization problem for networked control systems (NCSs) with unbound process noise, where sensors and controllers are connected via noiseless digital channels carrying a finite number of bits per unit time. A sufficient condition for stabilization of NCSs, which relies on a variable-rate digital link used to transmit state measurements, is derived. A lower bound of data rates, above which there exists a quantization, coding and control scheme to guarantee both stabilization and a prescribed control performance of the unstable discrete-time plant, is presented. An illustrative example is given to demonstrate the effectiveness of the proposed method
Identification of genotype 4 Hepatitis E virus binding proteins on swine liver cells
Hepatitis E virus (HEV) is a zoonotic pathogen of which several species of animal were reported as reservoirs. Swine stands out as the major reservoir for HEV infection in humans, as suggested by the close genetic relationship of swine and human virus and cross-species infection of HEV. Up to now, the mechanism of cross-species infection of HEV from swine to humans is still unclear. This study sought to identify receptor element for genotype 4 HEV on swine liver cells using the viral overlay protein binding assay (VOPBA) technique and Mass Spectrometry fingerprinting. A single virus binding band with natural molecular weight about 55 kDa was observed, and mass spectrometry revealed that this virus binding band contained 31 different proteins. Infection inhibition assay suggested that this 55 kDa protein could prevent HEV from infecting its susceptible A549 cell line, which was further confirmed by the HEV genome detecting in the inoculated cells. Further research should be performed to elucidate the accurate receptor of HEV on the swine liver cells
Synchronous Gastric Carcinoma and Nodal Malignant Lymphoma: A Rare Case Report and Literature Review
Synchronous double malignancies of gastric carcinoma (GC) and malignant lymphoma (ML) are rare and very difficult to treat. We report a case of synchronous GC and nodal ML, regarding which clinical and pathological features and treatment are discussed. A 68-year-old woman with a history of inguinal hernia was admitted for abdominal pain and high fever and subsequently underwent herniorrhaphy, but the fever remained. Computerized tomography showed a stomach mass and multiple enlarged lymph nodes in the abdominal cavity and inguinal regions. Gastric adenocarcinoma coexistent with advanced in situ follicular lymphoma was confirmed by endoscopy, biopsy of inguinal lymph nodes and bone marrow examination. Two chemotherapy regimens, R-CHOP (rituximab, cyclophosphamide, perarubicin, vincristine and prednisone) and systemic therapy (5-fluorouracil and calcium folinate) combined with regional perfusion (oxaliplatin and etoposide) through the left gastric artery were performed at intervals against ML and GC, respectively. Partial remission in both tumors was achieved after 4 courses of treatment, but the patient finally died of heart failure. Scrupulous biopsy of non-draining lymph nodes in patients with gastrointestinal carcinomas is supposed to improve the diagnostic rate of simultaneous nodal ML. The interval chemotherapy strategy with two independent regimens is beneficial for such patients, especially for those unable to tolerate major surgery
Rapid Remission in Peripheral T-Cell Lymphoma of the Nasal Type by the Bortezomib plus CHOP Therapy
Peripheral T-cell lymphoma (PTCL) is rare and difficult to treat for its high relapse rate. The authors report a case of PTCL of the skin, regarding which clinical and pathological features, treatment, and prognosis were discussed. A 66-year-old woman was admitted with complaints of enlarging erythematous noduloplaques on the right anterior tibial skin for one year and similar lesions on the left for 6 months. Surgical resection of right leg lesion and biopsy of enlarged inguinal lymph nodes histologically indicated a PTCL of the nasal type. The patient was treated by CHOP plus bortezomib, reached complete remission just after two courses of chemotherapy and then received another two as consolidation. The patient remained in remission for 11 months until local relapse. As for cutaneous lesions, detailed lymph node examination and prompt tissue biopsy are judicious choices prior to any medical management. The chemotherapy consisting of bortezomib and CHOP is safe and efficient in PTCL of the skin
A study on transmitted intensity of disturbance for air-spaced Glan-type polarizing prisms
We study theoretically and experimentally the transmission intensity of
polarized light through the air-spaced Glan-type polarizing prsims. It is found
that the variation of the transmitted intensity with the rotation angle
deviates from Malus Law, exhibiting a cyclic fluctuation with the rotation
angle. The occurrence of the disturbance is explained by the use of an argument
based on the interference effect produced from the air-gap in the prisms. The
theoretcal results are well agreed with the experimental ones. By selecting the
proper cut angle of prism and reducing the thickness of air-gap in prism, the
disturbance may be minimized.Comment: 5 pages, 10 figures, to be published in Optics Communication
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