Aims
The contribution of glycaemic variability to the microvascular complication of diabetes has not been established. We examined whether there is an independent association between indices of ...glycaemic variability in continuous glucose monitoring and extent of albuminuria.
Methods
A total of 173 patients with Type 2 diabetes (without insulin therapy, n = 96; with insulin therapy, n = 77) who had unexplained large fluctuations in blood glucose values underwent three‐day continuous glucose monitoring. We used a multinomial logistic regression model to determine whether the indices of glycaemic variability independently affected the odds of having a spot urine albumin/creatinine ratio of 30–299 mg/g and ≥ 300 mg/g.
Results
Higher standard deviation (P = 0.002), mean of daily differences (P = 0.023) and mean amplitude of glycaemic excursion (P = 0.043) significantly increased the odds of having a urine albumin/creatinine ratio of ≥ 300 mg/g. In multivariable analysis, only higher standard deviation, but not mean amplitude of glycaemic excursion and mean of daily differences, independently increased the odds of having a urine albumin/creatinine ratio of ≥ 300 mg/g (P = 0.025). Coefficient of variation (sd/mean) was not associated with the odds of having a urine albumin/creatinine ratio of 30–299 or ≥ 300 mg/g.
Conclusions
The independent association between standard deviation and the extent of albuminuria was lost when the measures were normalized by mean glucose level. At least in terms of relative measures of glycaemic variability, we failed to demonstrate an independent association between glycaemic variability and albuminuria extent in patients with inadequately controlled Type 2 diabetes.
What's new?
The contribution of glycaemic variability to the microvascular complication of diabetes has not been established.
We examined whether there is an independent association between indices of glycaemic variability in continuous glucose monitoring and extent of albuminuria.
This is the first continuous glucose monitoring‐based study to explore an association between various measures of glycaemic variability and degree of microvascular complication in a large clinical database composed of patients with inadequately controlled Type 2 diabetes.
The results of this study underline the importance of considering the contribution of mean glucose to the glycaemic variability indices, which has been frequently overlooked in the previous studies.
We present microlensing events in the 2015 Korea Microlensing Telescope Network (KMTNet) data and our procedure for identifying these events. In particular, candidates were detected with a novel ..."completed-event" microlensing event-finder algorithm. The algorithm works by making linear fits to a grid of point-lens microlensing models. This approach is rendered computationally efficient by restricting u0 to just two values (0 and 1), which we show is quite adequate. The implementation presented here is specifically tailored to the commission-year character of the 2015 data, but the algorithm is quite general and has already been applied to a completely different (non-KMTNet) data set. We outline expected improvements for 2016 and future KMTNet data. The light curves of the 660 "clear microlensing" and 182 "possible microlensing" events that were found in 2015 are presented along with our policy for their public release.
Aims/hypothesis
The unfolded protein response (UPR) in endoplasmic reticulum (ER) and autophagy are known to be related. We investigated the role of autophagy in UPR of pancreatic beta cells and the ...susceptibility of autophagy-deficient beta cells to the ER stress that is implicated in the development of diabetes.
Methods
Rat insulin promoter (RIP)-
Cre
+
;autophagy-related 7 (
Atg7
)
F/W
mice were bred with
ob/w
mice to derive RIP-
Cre
+
;
Atg7
F/F
-
ob/ob
mice and to induce ER stress in vivo.
GFP-LC3
+
-
ob/ob
mice were generated to examine in vivo autophagic activity. Real-time RT-PCR was performed to study the expression of the genes of the UPR machinery. Proteolysis was assessed by determining release of incorporated radioactive leucine.
Results
Production of UPR machinery was reduced in autophagy-deficient beta cells, which was associated with diminished production of p85α and p85β regulatory subunits of phosphoinositide 3-kinase. Because of compromised UPR machinery, autophagy-deficient beta cells were susceptible to ER stressors in vitro. When mice with beta cell-specific autophagy deficiency, which have mild hyperglycaemia, were bred with
ob/ob
mice to induce ER stress in vivo, severe diabetes developed, which was accompanied by an increase in beta cell death and accumulation of reactive oxygen species. The increased demand for UPR present in obesity was unmet in autophagy-deficient beta cells. Autophagy level and autophagic activity were enhanced by lipid, while proteolysis was reduced.
Conclusions/interpretation
These results suggest that autophagy is important for intact UPR machinery and appropriate UPR in response to lipid injury that increases demand for UPR. Autophagy deficiency in pancreatic beta cells may contribute to the progression from obesity to diabetes.
Quantum Algorithms for Quantum Field Theories Jordan, Stephen P.; Lee, Keith S. M.; Preskill, John
Science (American Association for the Advancement of Science),
06/2012, Letnik:
336, Številka:
6085
Journal Article
Recenzirano
Quantum field theory reconciles quantum mechanics and special relativity, and plays a central role in many areas of physics. We developed a quantum algorithm to compute relativistic scattering ...probabilities in a massive quantum field theory with quartic self-interactions (ф⁴ theory) in spacetime of four and fewer dimensions. Its run time is polynomial in the number of particles, their energy, and the desired precision, and applies at both weak and strong coupling. In the strong-coupling and high-precision regimes, our quantum algorithm achieves exponential speedup over the fastest known classical algorithm.
Background and purpose
High blood pressure (BP) at presentation is associated with poor outcomes in acute ischaemic stroke, but serial BP measurements may better delineate the clinical implications ...of BP. The aim was to investigate the association between various BP parameters and functional outcomes in acute ischaemic stroke patients treated with endovascular thrombectomy (EVT).
Methods
This study reports a retrospective analysis of a prospective registry of a comprehensive stroke centre. Patients treated with EVT due to large vessel occlusion in the anterior circulation were enrolled. BP was measured hourly during the first 24 h after admission. Associations of various BP parameters, including BP variability, with functional outcomes at 3 months, including good outcomes (modified Rankin Scale score of 0–2), were analysed.
Results
Of the 378 enrolled patients (mean age 70 ± 11 years, male 54.2%), 313 (82.8%) achieved successful reperfusion after EVT, and 149 (39.4%) had good outcomes at 3 months. Higher mean systolic BP each 10 mmHg increase, odds ratio 0.82 (0.69–0.97) and higher systolic successive variation (SV) each 10% increase, odds ratio 0.37 (0.18–0.76) were associated with a reduced likelihood of achieving good outcomes. In addition, reperfusion status after EVT moderated the influence of higher systolic SV on good outcomes (Pint = 0.05).
Conclusion
The results showed that a higher mean systolic BP and systolic SV during the first 24 h of EVT reduced the likelihood of good outcomes at 3 months. The effects of these parameters on outcomes are more substantial amongst patients with successful reperfusion after EVT, suggesting that different BP control strategies should be employed according to reperfusion status.
Click here to view the accompanying paper in this volume.
We report the discovery of a giant planet in the OGLE-2017-BLG-1522 microlensing event. The planetary perturbations were clearly identified by high-cadence survey experiments despite the relatively ...short event timescale of tE ∼ 7.5 days. The Einstein radius is unusually small, θE = 0.065 mas, implying that the lens system either has very low mass or lies much closer to the microlensed source than the Sun, or both. A Bayesian analysis yields component masses and source-lens distance , implying that this is a brown-dwarf/Jupiter system that probably lies in the Galactic bulge, a location that is also consistent with the relatively low lens-source relative proper motion = 3.2 0.5 mas yr−1. The projected companion-host separation is , indicating that the planet is placed beyond the snow line of the host, i.e., asl ∼ 0.12 au. Planet formation scenarios combined with the small companion-host mass ratio q ∼ 0.016 and separation suggest that the companion could be the first discovery of a giant planet that formed in a protoplanetary disk around a brown-dwarf host.
Current microlensing surveys are sensitive to free-floating planets down to Earth-mass objects. All published microlensing events attributed to unbound planets were identified based on their short ...timescale (below two days), but lacked an angular Einstein radius measurement (and hence lacked a significant constraint on the lens mass). Here, we present the discovery of a Neptune-mass free-floating planet candidate in the ultrashort (tE = 0.320 0.003 days) microlensing event OGLE-2016-BLG-1540. The event exhibited strong finite-source effects, which allowed us to measure its angular Einstein radius of θE = 9.2 0.5 as. There remains, however, a degeneracy between the lens mass and distance. The combination of the source proper motion and source-lens relative proper motion measurements favors a Neptune-mass lens located in the Galactic disk. However, we cannot rule out that the lens is a Saturn-mass object belonging to the bulge population. We exclude stellar companions up to ∼15 au.
Bone marrow‐derived early endothelial progenitor cells (BM‐EPCs) are a clinical tool for enhancing revascularization. However, the therapeutic efficacy of co‐transplantation of BM‐EPC with islets has ...not been investigated. In this study, marginal mass islets were co‐transplanted with or without BM‐EPCs under the kidney capsules of syngeneic streptozotocin‐induced diabetic mice. Using green fluorescent protein transgenic (GFP‐Tg) mice as BM‐EPC and islet donors or recipients, the role of EPCs in revascularization was assessed for graft morphology, vascular density and fate of EPCs by immunohistochemistry. Islet‐EPC co‐transplantation improved the outcome of islet transplantation as measured by glucose tolerance, serum insulin level and diabetes reversal rate, compared with transplantation of islets alone. Between groups, the morphology of islet grafts showed significant differences in size and composition of grafted endocrine tissues. Significantly more vessel density derived from donors and recipients was detected with islet‐EPC co‐transplantation. Abundant GFP‐Tg mice‐derived BM‐EPCs (GFP‐EPCs) were observed in or around islet grafts and incorporated into CD31‐positive capillaries. Remaining GFP‐EPCs expressed VEGF. In conclusion, co‐transplantation of islets with BM‐EPCs could improve the outcome of marginal mass islet transplantation by promoting revascularization and preserving islet morphology.
Co‐transplantation of bone marrow‐derived early endothelial progenitor cells improves islet graft organization and promotes graft revascularization by both a paracrine effect and direct incorporation into vascular endothelial cells.
Abstract
We measured hardness, modulus of elasticity, and, for the first time, loss tangent, energy of fracture, abrasion resistance, and impact resistance of zinc- and manganese-enriched materials ...from fangs, stings and other “tools” of an ant, spider, scorpion and nereid worm. The mechanical properties of the Zn- and Mn-materials tended to cluster together between plain and biomineralized “tool” materials, with the hardness reaching, and most abrasion resistance values exceeding, those of calcified salmon teeth and crab claws. Atom probe tomography indicated that Zn was distributed homogeneously on a nanometer scale and likely bound as individual atoms to more than ¼ of the protein residues in ant mandibular teeth. This homogeneity appears to enable sharper, more precisely sculpted “tools” than materials with biomineral inclusions do, and also eliminates interfaces with the inclusions that could be susceptible to fracture. Based on contact mechanics and simplified models, we hypothesize that, relative to plain materials, the higher elastic modulus, hardness and abrasion resistance minimize temporary or permanent tool blunting, resulting in a roughly 2/3 reduction in the force, energy, and muscle mass required to initiate puncture of stiff materials, and even greater force reductions when the cumulative effects of abrasion are considered. We suggest that the sharpness-related force reductions lead to significant energy savings, and can also enable organisms, especially smaller ones, to puncture, cut, and grasp objects that would not be accessible with plain or biomineralized “tools”.
Quantum plasmonics Tame, M. S.; McEnery, K. R.; Özdemir, Ş. K. ...
Nature physics,
06/2013, Letnik:
9, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Quantum plasmonics is a rapidly growing eld of research that involves the study of the quantum properties of light and its interaction with matter at the nanoscale. Here, surface ...plasmonselectromagnetic excitations coupled to electron charge density waves on metaldielectric interfaces or localized on metallic nanostructuresenable the connement of light to scales far below that of conventional optics. We review recent progress in the experimental and theoretical investigation of the quantum properties of surface plasmons, their role in controlling lightmatter interactions at the quantum level and potential applications. Quantum plasmonics opens up a new frontier in the study of the fundamental physics of surface plasmons and the realization of quantum-controlled devices, including single-photon sources, transistors and ultra-compact circuitry at the nanoscale.
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