1,509 research outputs found
Luttinger-volume violating Fermi liquid in the pseudogap phase of the cuprate superconductors
Based on the NMR measurements on BiSrLaCuO
(La-Bi2201) in strong magnetic fields, we identify the non-superconducting
pseudogap phase in the cuprates as a Luttinger-volume violating Fermi liquid
(LvvFL). This state is a zero temperature quantum liquid that does not break
translational symmetry, and yet, the Fermi surface encloses a volume smaller
than the large one given by the Luttinger theorem. The particle number enclosed
by the small Fermi surface in the LvvFL equals the doping level , not the
total electron number . Both the phase string theory and the dopon
theory are introduced to describe the LvvFL. For the dopon theory, we can
obtain a semi-quantitative agreement with the NMR experiments.Comment: The final version in PR
Uncertainty quantification of silicon photonic devices with correlated and non-Gaussian random parameters
catena-Poly[[[diaquaÂbis(1H-indole-3-acetato-κO)cobalt(II)]-μ-4,4′-bipyridine-κ2 N:N′] tetraÂhydrate]
The 4,4′-bipyridine spacer in the title compound, [Co(C10H8NO2)2(C10H8N2)(H2O)2]·4H2O, links the diaquaÂcobalt(II) dicarboxylÂate units into a linear chain; the metal atom lies on a center of inversion in an octaÂhedral environment. The coordinated and uncoordinated water molÂecules interÂact through O—H⋯O hydrogen bonds to form a three-dimensional network
Evolution from unconventional spin density wave to superconductivity and a novel gap-like phase in NaFe1-xCoxAs
Similar to the cuprate high TC superconductors, the iron pnictide
superconductors also lie in close proximity to a magnetically ordered phase. A
central debate concerning the superconducting mechanism is whether the local
magnetic moments play an indispensable role or the itinerant electron
description is sufficient. A key step for resolving this issue is to acquire a
comprehensive picture regarding the nature of various phases and interactions
in the iron compounds. Here we report the doping, temperature, and spatial
evolutions of the electronic structure of NaFe1-xCoxAs studied by scanning
tunneling microscopy. The spin density wave gap in the parent state is observed
for the first time, which shows a strongly asymmetric lineshape that is
incompatible with the conventional Fermi surface nesting scenario. The
optimally doped sample exhibits a single, symmetric energy gap, but in the
overdoped regime another asymmetric gap-like feature emerges near the Fermi
level. This novel gap-like phase coexists with superconductivity in the ground
state, persists deep into the normal state, and shows strong spatial
variations. The characteristics of the three distinct low energy states, in
conjunction with the peculiar high energy spectra, suggest that the coupling
between the local moments and itinerant electrons is the fundamental driving
force for the phases and phase transitions in the iron pnictides.Comment: 4 figures + supplementary informatio
Clinical efficacy and tendon integrity of patients with subscapularis tear by the technique of arthroscopic single external row repair
BackgroundWith the development of arthroscopic technology and equipment, arthroscopy can effectively repair the tear of the subscapular muscle. However, it is difficult to expose the subscapular muscle and operate it under a microscope. In this study, the SwiveLock® C external row anchor under arthroscopy was applied to repair the tear of the subscapular muscle in a single row, which is relatively easy to operate with reliable suture and fixation, and its efficacy was evaluated.PurposeThis study aimed to assess the clinical efficacy and the tendon integrity of patients who had subscapularis tears by adopting the single-row repair technique with a SwiveLock® C external row anchor.MethodsPatients who had the subscapular muscle tear either with or without retraction were included, and their follow-up time was at least 1 year. The degree of tendon injury was examined by magnetic resonance imaging (MRI) and confirmed by arthroscopy. The tendon was repaired in an arthroscopic manner by utilizing the single-row technique at the medial margin of the lesser tuberosity. One double-loaded suture SwiveLock® C anchor was applied to achieve a strong fixation between the footprint and tendon. The range of motion, pain visual simulation score, American Shoulder and Elbow Surgeons (ASES) score, and Constant score of shoulder joint were evaluated for each patient before the operation, 3 months after the operation, and at least 1 year after the operation.ResultsIn total, 110 patients, including 31 males and 79 females, with an average age of 68.28 ± 8.73 years were included. Arthroscopic repair of the subscapular tendon with SwiveLock® C external anchor can effectively improve the range of motion of the shoulder joint. At the last follow-up, the forward flexion of the shoulder joint increased from 88.97 ± 26.33° to 138.38 ± 26.48° (P < 0.05), the abduction range increased from 88.86 ± 25.27° to 137.78 ± 25.64° (P < 0.05), the external rotation range increased from 46.37 ± 14.48° to 66.49 ± 14.15° (P < 0.05), and the internal rotation range increased from 40.03 ± 9.01° to 57.55 ± 7.43° (P < 0.05). The clinical effect is obvious. The constant shoulder joint score increased from 40.14 ± 15.07 to 81.75 ± 11.00 (P < 0.05), the ASES score increased from 37.88 ± 13.24 to 82.01 ± 9.65 (P < 0.05), and the visual analog scale score decreased from 5.05 ± 2.11 to 1.01 ± 0.85 (P < 0.05). In the 6th month after the operation, two cases (1.81%) were confirmed to have re-tears via MRI.ConclusionIn this study, we repaired the subscapularis muscle with a single-row technique fixed by SwiveLock® C anchor and FiberWire® sutures and evaluated its efficacy. The results showed that the clinical effect of single-row arthroscopic repair was satisfactory and that reliable tendon healing could be achieved
Clinical outcomes after vascular reconstruction using synthetic grafts for limb salvage in patients with lower extremity sarcoma: a single-center retrospective experience
IntroductionLimb-salvage surgery has become the mainstream approaches for the treatment of sarcoma in the lower extremity. In cases where the sarcoma infiltrates the primary vessel, concurrent resection of the vessels and vascular reconstruction are required to ensure sufficient resection and preservation of limb function. The objective of this study is to assess the clinical outcomes of patients who underwent vascular reconstruction utilizing synthetic grafts for limb salvage, specifically in terms of postoperative complications and limb functional status.MethodsBetween September 2016 and October 2021, 15 consecutive patients who underwent 15 arterial and 3 venous reconstruction procedures were included in this retrospective study. Incidence of postoperative morbidity, graft patency, rate of limb salvage, and overall survival of patients were analyzed.ResultsThe median follow-up was 12.5 months (range, 4.5-72.0). Graft thrombosis occurred in 5 patients (33.3%) and graft occlusion occurred in 3 patients (20.0%). The median overall survival was 28.0 months with the estimated 2-year and 5-year overall survival of 57.8% and 43.4% respectively. The 1-year and 2-year estimated patency rates of arterial reconstructions were 82.3% and 62.1%, respectively. None of the included patients with limb amputation were observed as a consequence of severe vascular complications, while two patients underwent amputation due to the repeat recurrence, resulting in a limb salvage rate of 86.7%.ConclusionOur results show that the combination of vascular reconstruction and oncologic resection is a feasible option for preserving limbs in cases of musculoskeletal sarcoma with vessel involvement in the lower extremity. When vascular reconstruction surgery is performed, synthetic substitutes can be effectively used with low perioperative morbidity and an acceptable rate of limb salvage
Extremely brilliant GeV γ-rays from a two-stage laser-plasma accelerator
Recent developments in laser-wakefield accelerators have led to compact ultrashort X/γ-ray sources that can deliver peak brilliance comparable with conventional synchrotron sources. Such sources normally have low efficiencies and are limited to 107-8 photons/shot in the keV to MeV range. We present a novel scheme to efficiently produce collimated ultrabright γ-ray beams with photon energies tunable up to GeV by focusing a multi-petawatt laser pulse into a two-stage wakefield accelerator. This high-intensity laser enables efficient generation of a multi-GeV electron beam with a high density and tens-nC charge in the first stage. Subsequently, both the laser and electron beams enter into a higher-density plasma region in the second stage. Numerical simulations demonstrate that more than 1012 γ-ray photons/shot are produced with energy conversion efficiency above 10% for photons above 1 MeV, and the peak brilliance is above 1026 photons s-1 mm-2 mrad-2 per 0.1% bandwidth at 1 MeV. This offers new opportunities for both fundamental and applied research
Bubble in the Whale: Identifying the Optical Counterparts and Extended Nebula for the Ultraluminous X-ray Sources in NGC 4631
We present a deep optical imaging campaign on the starburst galaxy NGC 4631
with CFHT/MegaCam. By supplementing the HST/ACS and Chandra/ACIS archival data,
we search for the optical counterpart candidates of the five brightest X-ray
sources in this galaxy, four of which are identified as ultraluminous X-ray
sources (ULXs). The stellar environments of the X-ray sources are analyzed
using the extinction-corrected color-magnitude diagrams and the isochrone
models. We discover a highly asymmetric bubble nebula around X4 which exhibits
different morphology in the H and [O III] images. The [O III]/H
ratio map shows that the H-bright bubble may be formed mainly via the
shock ionization by the one-sided jet/outflow, while the more compact [O III]
structure is photoionized by the ULX. We constrain the bubble expansion
velocity and interstellar medium density with the MAPPINGS V code, and hence
estimate the mechanical power injected to the bubble as erg s and the corresponding bubble age of yr. Relativistic jets are needed to provide such level of mechanical
power with a mass-loss rate of . Besides
the accretion, the black hole spin is likely an additional energy source for
the super-Eddington jet power.Comment: 17 pages, 10 figures, accepted by Ap
Generation of single-cycle relativistic infrared pulses at wavelengths above 20 µm from density-tailored plasmas
Ultra-intense short-pulse light sources are powerful tools for a wide range of applications. However, relativistic short-pulse lasers are normally generated in the near-infrared regime. Here, we present a promising and efficient way to generate tunable relativistic ultrashort pulses with wavelengths above 20 µm in a density-tailored plasma. In this approach, in the first stage, an intense drive laser first excites a nonlinear wake in an underdense plasma, and its photon frequency is then downshifted via phase modulation as it propagates in the plasma wake. Subsequently, in the second stage, the drive pulse enters a lower-density plasma region so that the wake has a larger plasma cavity in which longer-wavelength infrared pulses can be produced. Numerical simulations show that the resulting near-single-cycle pulses cover a broad spectral range of 10–40 µm with a conversion efficiency of ∼2.1% (∼34 mJ pulse energy). This enables the investigation of nonlinear infrared optics in the relativistic regime and offers new possibilities for the investigation of ultrafast phenomena and physics in strong fields
Efficacy mechanisms research progress of the active components in the characteristic woody edible oils
Woody edible oils are a type of vegetable oil. Woody edible oils like olive oil have greater quantities of unsaturated fatty acids (UFAs), particularly essential FAs, as well as vitamin E, phytosterols, and other nutrients that are becoming more vital in human health. As a result, finding high-quality woody oil resource plants is critical to ensuring enough edible oil supply. As six novel woody crops, Paeonia suffruticosa, Plukenetia volubilis, Acer truncatum, Olea europaea, Camellia sinensis, and Camellia oleifera are characterized by high oil production, widespread cultivation, adaptability, and various active ingredients. The six woody crop oils contain UFAs (e.g., α-linolenic acid, oleic acid, and linoleic acid), vitamin E, polyphenols, phytosterols, and so forth. The presence of these active ingredients confers anti-inflammatory, antioxidant, cholesterol and lipid metabolism regulating, blood lipid lowering, immune boosting, memory improving, intestinal flora regulating, and other properties to the oils, which are beneficial to body health. This article examined in depth the seed resources, FA composition, active component kinds, active ingredient efficacy mechanism, and physiological impacts of these six novel woody crop oils. These developments lay a solid platform for further study and development of these woody oil crops.This work was supported by the Key Research and Development Program of Zhejiang Province (No. 2021C02002), Zhejiang Provincial Natural Sciences Foundation of China under Grant (No. LZ22C200006), Top young talents of the ten thousand talents program of Zhejiang Province (ZJWR0308016), Key R&D projects in Zhejiang Province (2023C04010), and Zhejiang Basic Public Welfare Research Project (LGN21C200006). Agusti Romero acknowledges financial support from the CERCA Program from the Generalitat of Catalonia. We would like to thank all contributors of the current study for their concepts, ideas, contribution, and provision.info:eu-repo/semantics/publishedVersio
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