2,071 research outputs found
Quantum state magnification
Quantum metrology exploits entangled states of particles to improve sensing
precision beyond the limit achievable with uncorrelated particles. All previous
methods required detection noise levels below this standard quantum limit to
realize the benefits of the intrinsic sensitivity provided by these states.
Remarkably, a recent proposal has shown that, in principle, such low-noise
detection is not a necessary requirement. Here, we experimentally demonstrate a
widely applicable method for entanglement-enhanced measurements without
low-noise detection. Using an intermediate magnification step, we perform
squeezed state metrology 8 dB below the standard quantum limit with a detection
system that has a noise floor 10 dB above the standard quantum limit. Beyond
its conceptual significance, this method eases implementation complexity and is
expected to find application in next generation quantum sensors
X-ray photoemission study of NiS_{2-x}Se_x (x = 0.0 - 1.2)
Electronic structure of NiS_{2-x}Se_x system has been investigated for
various compositions (x) using x-ray photoemission spectroscopy. An analysis of
the core level as well as the valence band spectra of NiS_2 in conjunction with
many-body cluster calculations provides a quantitative description of the
electronic structure of this compound. With increasing Se content, the on-site
Coulomb correlation strength (U) does not change, while the band width W of the
system increases, driving the system from a covalent insulating state to a
pd-metallic state.Comment: 19 pages, 6 figures, To appear in Phys. Rev. B, 200
Structural evolution drives diversification of the large LRR-RLK gene family
Cells are continuously exposed to chemical signals that they must discriminate between and respond to appropriately. In embryophytes, the leucine‐rich repeat receptor‐like kinases (LRR‐RLKs) are signal receptors critical in development and defense. LRR‐RLKs have diversified to hundreds of genes in many plant genomes. Although intensively studied, a well‐resolved LRR‐RLK gene tree has remained elusive. To resolve the LRR‐RLK gene tree, we developed an improved gene discovery method based on iterative hidden Markov model searching and phylogenetic inference. We used this method to infer complete gene trees for each of the LRR‐RLK subclades and reconstructed the deepest nodes of the full gene family. We discovered that the LRR‐RLK gene family is even larger than previously thought, and that protein domain gains and losses are prevalent. These structural modifications, some of which likely predate embryophyte diversification, led to misclassification of some LRR‐RLK variants as members of other gene families. Our work corrects this misclassification. Our results reveal ongoing structural evolution generating novel LRR‐RLK genes. These new genes are raw material for the diversification of signaling in development and defense. Our methods also enable phylogenetic reconstruction in any large gene family
Crystal structure of [4-(2-methoxyphenyl)-3-methyl-1-phenyl-6-trifluoromethyl-1H-pyrazolo[3,4-b]pyridin-5-yl](thiophen-2-yl)methanone
The title compound, C[subscript 26]H[subscript 18]F[subscript 3]N[subscript 3]O[subscript 2]S, a 2-methoxy-substituted derivative, is closely related to its 4-methyl- and 4-chloro-substituted analogues and yet displays no structural relationships with them. The thiophene ring is disorder free and the -CF[subscript 3] group exhibits disorder, respectively, in contrast and similar to that observed in the 4-methyl- and 4-chloro-substituted derivatives. The torsion angle which defines the twist of the thiophene ring is -69.6 (2)° (gauche) in the title compound, whereas it is anticlinal in the 4-methyl- and 4-chloro-substituted derivatives, with respective values of 99.9 (2) and 99.3 (2)°. The absence of disorder in the thiophene ring facilitates one of its ring C atoms to participate in the lone intermolecular C-H...O hydrogen bond present in the crystal, leading to a characteristic C(5) chain graph-set motif linking molecules related through glides along [010]. An intramoleculr C-H...N hydrogen bond also occurs
Boron and Gamma ray irradiation effects on I-V and C-V characteristics of photo detector MRD 500
This paper describes the effect of 30- and 60-MeV Boron ion and Gamma ray (Co-60) irradn. effects on silicon photo detector (MRD 500 Motorola manufd.) for various fluence/doses. The devices are systematically investigated by I-V and C-V measurements. The radiation induced elec. degrdn. is studied from I-V measurements. C-V measurements are made to est. the effect of irradn. on the doping concn. of the devices. The characteristics studied in this investigation show that Si PIN photodiodes are suitable for use in high radiation environment
Competitive inhibition of survivin using a cell-permeable recombinant protein induces cancer-specific apoptosis in colon cancer model
Endogenous survivin expression has been related with cancer survival, drug resistance, and metastasis. Therapies targeting survivin have been shown to significantly inhibit tumor growth and recurrence. We found out that a cell-permeable dominant negative survivin (SurR9-C84A, referred to as SR9) competitively inhibited endogenous survivin and blocked the cell cycle at the G1/S phase. Nanoencapsulation in mucoadhesive chitosan nanoparticles (CHNP) substantially increased the bioavailability and serum stability of SR9. The mechanism of nanoparticle uptake was studied extensively in vitro and in ex vivo models. Our results confirmed that CHNP-SR9 protected primary cells from autophagy and successfully induced tumor-specific apoptosis via both extrinsic and intrinsic apoptotic pathways. CHNP-SR9 significantly reduced the tumor spheroid size (three-dimensional model) by nearly 7-fold. Effects of SR9 and CHNP-SR9 were studied on 35 key molecules involved in the apoptotic pathway. Highly significant (4.26-fold, P≤0.005) reduction in tumor volume was observed using an in vivo mouse xenograft colon cancer model. It was also observed that net apoptotic (6.25-fold, P≤0.005) and necrotic indexes (3.5-fold, P≤0.05) were comparatively higher in CHNP-SR9 when compared to void CHNP and CHNP-SR9 internalized more in cancer stem cells (4.5-fold, P≤0.005). We concluded that nanoformulation of SR9 did not reduce its therapeutic potential; however, nanoformulation provided SR9 with enhanced stability and better bioavailability. Our study presents a highly tumor-specific protein-based cancer therapy that has several advantages over the normally used chemotherapeutics
Primary double tooth with partial anodontia of permanent dentition: a case report
Dental anomalies of number and forms may occur in the primary and permanent dentition. Various terms have
been used to describe dental twinning anomalies: gemination, fusion, concrescence, double teeth, cojoined teeth,
twinned teeth, geminifusion and vicinifusion. Double tooth is a term used to describe connate tooth and includes
both dental fusion and gemination. The phenomenon of gemination occurs when two teeth develop from one single
bud leading to a larger tooth. Fusion is a condition in which the crowns of two separate teeth have been joined toge-
ther during the crown development. Fusion occurs infrequently but could cause esthetic, spacing and periodontal
problems. The present article highlights the presence of a primary double tooth in an 11 year old boy involving
primary mandibular left lateral incisor and canine. Clinical examination and radiographic examination confirmed
the absence of the permanent left mandibular lateral incisor. Cases with primary double tooth necessitate careful
examination as they may be associated with anomalies in the succeeding permanent dentition and require proper
treatment plannin
Timing Offset Calibration of CZTI instrument aboard ASTROSAT
The radio as well as the high energy emission mechanism in pulsars is yet not
understood properly. A multi-wavelength study is likely to help in better
understanding of such processes. The first Indian space-based observatory,
ASTROSAT, has five instruments aboard, which cover the electromagnetic spectrum
from infra-red (1300 ) to hard X-ray (380 KeV). Cadmium Zinc Telluride
Imager (CZTI), one of the five instruments is a hard X-ray telescope functional
over an energy range of 20-380 KeV. We aim to estimate the timing offset
introduced in the data acquisition pipeline of the instrument, which will help
in time alignment of high energy time series with those from two other
ground-based observatories, viz. the Giant Meterwave Radio Telescope (GMRT) and
the Ooty Radio Telescope (ORT). PSR B0531+21 is a well-studied pulsar with
nearly aligned radio and hard X-ray pulse profiles. We use simultaneous
observations of this pulsar with the ASTROSAT, the ORT and the GMRT. The pulsar
was especially observed using the ORT with almost daily cadence to obtain good
timing solutions. We also supplement the ORT data with archival FERMI data for
estimation of timing noise. The timing offset of ASTROSAT instruments was
estimated from fits to arrival time data at the ASTROSAT and the radio
observatories. We estimate the offset between the GMRT and the ASTROSAT-CZTI to
be -4716 50 . The corresponding offset with the ORT was -29639
50 . The offsets between the GMRT and Fermi-LAT -5368 56
. (Abridged)Comment: 6 pages, 5 figures, 2 tables, Revised and Updated, accepted for
publication in A&
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