Spin Amplification for Magnetic Sensors Employing Crystal Defects

Recently there have been several theoretical and experimental studies of the prospects for magnetic field sensors based on crystal defects, especially nitrogen vacancy (NV) centres in diamond. Such systems could potentially be incorporated into an AFM-like apparatus in order to map the magnetic properties of a surface at the single spin level. In this Letter we propose an augmented sensor consisting of an NV centre for readout and an `amplifier' spin system that directly senses the local magnetic field. Our calculations show that this hybrid structure has the potential to detect magnetic moments with a sensitivity and spatial resolution far beyond that of a simple NV centre, and indeed this may be the physical limit for sensors of this class

Cholecystocolonic Fistula: Demonstrating the Need for Further Imaging Assessment Following an Abnormal Ultrasound Exam

Background Point of care ultrasound (PoCUS) is a diagnostic tool that can efficiently answer targeted clinical questions at the bedside.  Such questions include confirming or ruling out the presence of a specific complication suspected by the clinician, like an abdominal aortic aneurysm, for example. Proper identification of any such complication is reliant upon a fundamental knowledge and recognition of normal anatomy in each view, so the ultrasound provider can distinguish normal from a variety of hallmark pathologic signs. A positive finding warrants immediate changes in management, often including further imaging to guide interventions.  However,  indeterminate, or incidental findings unrelated to the patient’s chief complaint can be found.  While usually benign, sometimes these findings are indicative of an underlying pathology not initially suspected by the physician.   In these settings, PoCUS has limited diagnostic value, and therefore it is important to highlight the need for further imaging following discovery of abnormal or incidental findings on an ultrasound exam.    Case The patient was a 75-year-old female with COPD, coronary artery disease and hypertension. Her overall health declined after an admission for COVID pneumonia, which required treatment for oxygen. She never improved completely and was diagnosed with pulmonary fibrosis, likely secondary to COVID-19. She presented to our outpatient clinic for follow up from a recent hospitalization for respiratory decompensation and heart failure. During the visit she complained of intermittent right sided abdominal pain which had been present for a couple weeks. It was not associated with eating, and the pain did improve some after passing gas. The decision was made to perform a bedside ultrasound of her gallbladder to look for gallstones. Upon visualizing her gallbladder, hyperechoic shadowing in a smooth, circumferential nature filled the gallbladder. The differential included porceline gallbladder, stone filled gallbladder, or emphysematous cholecystitis. She was referred for further imaging, but before she could get imaging completed, she presented to the emergency department due to worsening pain. A CT scan of the abdomen showed an ill-defined soft tissue mass with surrounding inflammation involving the inferior right hepatic lobe, gallbladder and cecal visualization. Overall, given the surrounding inflammation this was favored to represent perforated cholecystitis with inflammatory fistula. Interventional radiology attempted to place a drain which was unsuccessful but did demonstrate fistulization with the colon. She later had a cholecystectomy performed, with a pathology report which detailed results showing metastatic poorly differentiated adenocarcinoma with signet ring and mucinous features. Oncology was consulted for treatment options, but unfortunately the patient passed away from cardiopulmonary compromise before treatment could be initiated.   Conclusion This case demonstrates the importance of follow up imaging for abnormal bedside ultrasound studies which do not follow the typical PoCUS pathway. Point of care ultrasound is used to answer a binary question, “Does my patient have a gallstone?” for example. If there are abnormal findings, or findings which do not correlate with the history and physical examination, more advanced imaging assessment is required and should be ordered by the point of care ultrasound provider.&nbsp

Playing popular science

Popular science is a critical form of science communication and dissemination. While scientific journals and detailed textbooks are well suited to dissemination of detailed theories and findings within academic communities, there is a definitive need to inform the general public of key scientific concepts and challenges. Indeed, this is increasingly seen as a central part of any research project or funding bid: in the United Kingdom, the Research Councils stipulate a need to consider public engagement and outreach in research proposals For scientists, the popular science book has long been a medium of choice, primarily because they already have a great deal of experience in writing. But in recent years scientific researchers have been increasingly engaged with other forms of popular science communication, including radio and television broadcasting. Early careers researchers are now provided with training in these areas, including guidance on how to develop programme proposals and how to write, present, direct, and edit materials for print, the airwaves, and screen. In effect, today’s scientists are expected to engage directly with popular science journalism not merely as scientific advisors, but as the writers, directors, and broadcasters.This event involved an exhibition and discussion of four popular science games, co-designed by scientific experts and designed and developed by students at Abertay University. The four games were: (1) Namaka by Crowbar Games Co-designed by Ecotoxicologist Dr Brian Quinn (2) Tides: A Shark Tale by Benthos Games Co-designed by Immunologist and sharks expert Dr Helen Dooley (3) Orbs by Quantessential Games Co-designed by Quantum Physicist Dr Erik Gauger (4) Cell Cycle by Type 3 Games Co-designed by Cell Biologist and cancer researcher Dr Adrian Sauri

Down-regulation of sfrp1 in a mammary epithelial cell line promotes the development of a cd44high/cd24low population which is invasive and resistant to anoikis

<p>Abstract</p> <p>Background</p> <p>The Wnt family of secreted proteins is implicated in the regulation of cell fate during development, as well as in cell proliferation, morphology, and migration. Aberrant activation of the Wnt/β-catenin signaling pathway leads to the development of several human cancers, including breast cancer. Secreted frizzled-related protein 1 (SFRP1) antagonizes this pathway by competing with the Frizzled receptor for Wnt ligands resulting in an attenuation of the signal transduction cascade. Loss of SFRP1 expression is observed in breast cancer, along with several other cancers, and is associated with poor patient prognosis. However, it is not clear whether the loss of SFRP1 expression predisposes the mammary gland to tumorigenesis.</p> <p>Results</p> <p>When SFRP1 is knocked down in a non-malignant immortalized mammary epithelial cell line (76 N TERT), nuclear levels of β-catenin rise and the Wnt pathway is stimulated. The SFRP1 knockdown cells exhibit increased expression of the pro-proliferative Cyclin D1 gene and increased cellular proliferation, undergo a partial epithelial-mesenchymal transition (EMT), are resistant to anchorage-independent cell death, exhibit increased migration, are significantly more invasive, and exhibit a CD24^low/CD44^highcell surface marker expression pattern.</p> <p>Conclusion</p> <p>Our study suggests that loss of SFRP1 allows non-malignant cells to acquire characteristics associated with breast cancer cells.</p

INDUCTION OF ABORTION BY STRANGE MALES IN PINE VOLE FEMALES THAT ARE: 1) TEN DAYS PREGNANT OR 2) PREGNANT AND LACTATING

Pregnant voles react to the presence of unfamiliar males by aborting the offspring they are carrying, entering estrus and mating with these new males. This phenomenon was first described in pine voles by Marks and Schadler (1979). At that time we reported that 84% of females that were four days along in their first pregnancy were induced by strange males to reject their embryos. These findings encouraged us to continue our investigations and this paper reports results on the abortion response caused by strange males in females ten days along in their first pregnancy (Experiment I) and on experienced pine vole mothers that are pregnant and are at the same time nursing a litter (Experiment II)

INDUCTION OF ABORTION BY STRANGE MALES IN PINE VOLE FEMALES THAT ARE: 1) TEN DAYS PREGNANT OR 2) PREGNANT AND LACTATING

Pregnant voles react to the presence of unfamiliar males by aborting the offspring they are carrying, entering estrus and mating with these new males. This phenomenon was first described in pine voles by Marks and Schadler (1979). At that time we reported that 84% of females that were four days along in their first pregnancy were induced by strange males to reject their embryos. These findings encouraged us to continue our investigations and this paper reports results on the abortion response caused by strange males in females ten days along in their first pregnancy (Experiment I) and on experienced pine vole mothers that are pregnant and are at the same time nursing a litter (Experiment II)

Ensemble based quantum metrology

The field of quantum metrology promises measurement devices that are fundamentally superior to conventional technologies. Specifically, when quantum entanglement is harnessed the precision achieved is supposed to scale more favourably with the resources employed, such as system size and the time required. Here we consider measurement of magnetic field strength using an ensemble of spins, and we identify a third essential resource: the initial system polarisation, i.e. the low entropy of the original state. We find that performance depends crucially on the form of decoherence present; for a plausible dephasing model, we describe a quantum strategy which can indeed beat the standard quantum limit

Quantum metrology with molecular ensembles

This work was supported by the EPSRC through QIP IRC (Grants No. GR/S82176/01 and No. GR/S15808/01), the National Research Foundation and Ministry of Education, Singapore, the DAAD, and the Royal Society.The field of quantum metrology promisesmeasurement devices that are fundamentally superior to conventional technologies. Specifically, when quantum entanglement is harnessed, the precision achieved is supposed to scale more favorably with the resources employed, such as system size and time required. Here, we consider measurement of magnetic-field strength using an ensemble of spin-active molecules. We identify a third essential resource: the change in ensemble polarization (entropy increase) during the metrology experiment. We find that performance depends crucially on the form of decoherence present; for a plausible dephasing model, we describe a quantum strategy, which can indeed beat the standard strategy.Publisher PDFPeer reviewe

Superabsorption of light via quantum engineering

Almost 60 years ago Dicke introduced the term superradiance to describe a signature quantum effect: N atoms can collectively emit light at a rate proportional to N^2. Even for moderate N this represents a significant increase over the prediction of classical physics, and the effect has found applications ranging from probing exciton delocalisation in biological systems, to developing a new class of laser, and even in astrophysics. Structures that super-radiate must also have enhanced absorption, but the former always dominates in natural systems. Here we show that modern quantum control techniques can overcome this restriction. Our theory establishes that superabsorption can be achieved and sustained in certain simple nanostructures, by trapping the system in a highly excited state while extracting energy into a non-radiative channel. The effect offers the prospect of a new class of quantum nanotechnology, capable of absorbing light many times faster than is currently possible; potential applications of this effect include light harvesting and photon detection. An array of quantum dots or a porphyrin ring could provide an implementation to demonstrate this effect

Phonon-Induced Rabi-Frequency Renormalization of Optically Driven Single InGaAs/GaAs Quantum Dots

The authors thank the EPSRC (U.K.) EP/G001642, and the QIPIRC U.K. for financial support. A. N. is supported by the EPSRC and B.W. L. by the Royal Society.We study optically driven Rabi rotations of a quantum dot exciton transition between 5 and 50 K, and for pulse areas of up to 14 pi. In a high driving field regime, the decay of the Rabi rotations is nonmonotonic, and the period decreases with pulse area and increases with temperature. By comparing the experiments to a weak-coupling model of the exciton-phonon interaction, we demonstrate that the observed renormalization of the Rabi frequency is induced by fluctuations in the bath of longitudinal acoustic phonons, an effect that is a phonon analogy of the Lamb shift.Peer reviewe