Valley-Tunable Even-Denominator Fractional Quantum Hall State in the Lowest Landau Level of an Anisotropic System.

Fractional quantum Hall states (FQHSs) at even-denominator Landau level filling factors (ν) are of prime interest as they are predicted to host exotic, topological states of matter. We report here the observation of a FQHS at ν=1/2 in a two-dimensional electron system of exceptionally high quality, confined to a wide AlAs quantum well, where the electrons can occupy multiple conduction-band valleys with an anisotropic effective mass. The anisotropy and multivalley degree of freedom offer an unprecedented tunability of the ν=1/2 FQHS as we can control both the valley occupancy via the application of in-plane strain, and the ratio between the strengths of the short- and long-range Coulomb interaction by tilting the sample in the magnetic field to change the electron charge distribution. Thanks to this tunability, we observe phase transitions from a compressible Fermi liquid to an incompressible FQHS and then to an insulating phase as a function of tilt angle. We find that this evolution and the energy gap of the ν=1/2 FQHS depend strongly on valley occupancy.

[Expression of GPNMB in renal eosinophilic tumors and its value in differential diagnosis].

Objective: To investigate the expression of glycoprotein non metastatic melanoma protein B (GPNMB) in renal eosinophilic tumors and to compare the value of GPNMB with CK20, CK7 and CD117 in the differential diagnosis of renal eosinophilic tumors. Methods: Traditional renal tumor eosinophil subtypes, including 22 cases of renal clear cell carcinoma eosinophil subtype (e-ccRCC), 19 cases of renal papillary cell carcinoma eosinophil subtype (e-papRCC), 17 cases of renal chromophobe cell carcinoma eosinophil subtype (e-chRCC), 12 cases of renal oncocytoma (RO) and emerging renal tumor types with eosinophil characteristics [3 cases of eosinophilic solid cystic renal cell carcinoma (ESC RCC), 3 cases of renal low-grade eosinophil tumor (LOT), 4 cases of fumarate hydratase-deficient renal cell carcinoma (FH-dRCC) and 5 cases of renal epithelioid angiomyolipoma (E-AML)], were collected at the Affiliated Drum Tower Hospital of Nanjing University Medical School from January 2017 to March 2022. The expression of GPNMB, CK20, CK7 and CD117 was detected by immunohistochemistry and statistically analyzed. Results: GPNMB was expressed in all emerging renal tumor types with eosinophil characteristics (ESC RCC, LOT, FH-dRCC) and E-AML, while the expression rates in traditional renal eosinophil subtypes e-papRCC, e-chRCC, e-ccRCC and RO were very low or zero (1/19, 1/17, 0/22 and 0/12, respectively); the expression rate of CK7 in LOT (3/3), e-chRCC (15/17), e-ccRCC (4/22), e-papRCC (2/19), ESC RCC (0/3), RO (4/12), E-AML(1/5), and FH-dRCC (2/4) variedly; the expression of CK20 was different in ESC RCC (3/3), LOT(3/3), e-chRCC(1/17), RO(9/12), e-papRCC(4/19), FH-dRCC(1/4), e-ccRCC(0/22) and E-AML(0/5), and so did that of CD117 in e-ccRCC(2/22), e-papRCC(1/19), e-chRCC(16/17), RO(10/12), ESC RCC(0/3), LOT(1/3), E-AML(2/5) and FH-dRCC(1/4). GPNMB had 100% sensitivity and 97.1% specificity in distinguishing E-AML and emerging renal tumor types (such as ESC RCC, LOT, FH-dRCC) from traditional renal tumor types (such as e-ccRCC, e-papRCC, e-chRCC, RO),respectively. Compared with CK7, CK20 and CD117 antibodies, GPNMB was more effective in the differential diagnosis (P<0.05). Conclusion: As a new renal tumor marker, GPNMB can effectively distinguish E-AML and emerging renal tumor types with eosinophil characteristics such as ESC RCC, LOT, FH-dRCC from traditional renal tumor eosinophil subtypes such as e-ccRCC, e-papRCC, e-chRCC and RO, which is helpful for the differential diagnosis of renal eosinophilic tumors.

Robust Quantum Hall Ferromagnetism near a Gate-Tuned ν=1 Landau Level Crossing.

In a low-disorder two-dimensional electron system, when two Landau levels of opposite spin or pseudospin cross at the Fermi level, the dominance of the exchange energy can lead to a ferromagnetic, quantum Hall ground state whose gap is determined by the exchange energy and has skyrmions as its excitations. This is normally achieved via applying either hydrostatic pressure or uniaxial strain. We study here a very high-quality, low-density, two-dimensional hole system, confined to a 30-nm-wide (001) GaAs quantum well, in which the two lowest-energy Landau levels can be gate tuned to cross at and near filling factor ν=1. As we tune the field position of the crossing from one side of ν=1 to the other by changing the hole density, the energy gap for the quantum Hall state at ν=1 remains exceptionally large, and only shows a small dip near the crossing. The gap overall follows a sqrt[B] dependence, expected for the exchange energy. Our data are consistent with a robust quantum Hall ferromagnet as the ground state.

[Study on the correlation between PPG and HVPG in patients with portal hypertension].

Objective: To explore the correlation between portal vein pressure gradient (PPG) and hepatic vein pressure gradient (HVPG) in patients with portal hypertension (PHT). Methods: 752 cases with portal hypertension (PHT) who underwent transjugular intrahepatic portosystemic shunt (TIPS) and met the enrollment criteria between January 2016 to December 2019 were analyzed for hepatic vein, inferior vena cava and portal vein pressure. Paired t-test was used for analysis. Pearson correlation test was used to estimate correlation coefficient and coefficient of determination. P<0.05 were considered statistically significant. Results: Wedged hepatic vein pressure (WHVP), portal vein pressure (PVP), correlation coefficient, and coefficient of determination were 27.98±8.95 mmHg, 33.85±7.33 mmHg, 0.329 (P<0.001), and 0.108, respectively. HVPG, PPG,correlation coefficient, and coefficient of determination were 16.84±7.97 mmHg, 25.11±6.95 mmHg (P<0.001), 0.145, and 0.021 (P<0.001), respectively. The difference between HVPG and PPG was greater than 5 mmHg in 524 cases, accounting for 69.7%. The difference between HVPG and PPG was within 5 mmHg or basically equal in 228 cases, accounting for 30.3%. The correlation coefficient between free hepatic venous pressure (FHVP) and inferior vena cava pressure (IVCP) was 0.568 (P<0.001), and the coefficient of determination was 0.323. According to the presence or absence of hepatic venous collaterals after balloon occluded hepatic angiography, they were divided into two groups: 157 (20.9%) cases in the group with hepatic venous collaterals, and 595 (79.1%) cases in the group without hepatic venous collaterals. The parameters of the two groups were compared: WHVP (15.73±3.63) mmHg vs. (31.22±6.90) mmHg, P<0.001; PVP (31.69±8.70) mmHg vs. (34.42±6.81) mmHg, P<0.001; HVPG (7.18±4.40) mmHg vs. (19.40±6.62) mmHg, P<0.001; PPG (24.24±8.11) mmHg vs. (25.34±6.60) mmHg, P<0.001; free hepatic venous pressure (FHVP) (8.58±3.37) mmHg vs. (11.82±5.07) mmHg , P<0.001; inferior vena cava pressure (IVCP) (7.45±3.29) mmHg vs. (9.09±4.14) mmHg, P<0.001. Conclusion: The overall correlation is poor between HVPG and PPG. HVPG of most patients is not an accurate representation of PPG, and the former is lower than the latter. Hepatic venous collateral formation is one of the important reasons for the serious underestimation of HVPG values.

Provision of emergency hyperbaric oxygen treatment for a patient during the COVID-19 pandemic.

The experience of managing a critically ill severe carbon monoxide poisoning patient suspected of possibly also suffering COVID-19 and requiring emergency hyperbaric oxygen treatment is described. Strategies used to minimise infection risk, modifications to practice and lessons learnt are described. All aerosol generating procedures such as endotracheal tube manipulation and suctioning should be undertaken in a negative pressure room. In the absence of in-chamber aerosol generating procedures, an intubated patient presents less risk than that of a non-intubated, symptomatically coughing patient. Strict infection control practices, contact precautions, hospital workflows and teamwork are required for the successful HBOT administration to an intubated COVID-19 suspect patient.

Multimodal cross-registration and quantification of metric distortions in marmoset whole brain histology using diffeomorphic mappings.

Whole brain neuroanatomy using tera-voxel light-microscopic data sets is of much current interest. A fundamental problem in this field is the mapping of individual brain data sets to a reference space. Previous work has not rigorously quantified in-vivo to ex-vivo distortions in brain geometry from tissue processing. Further, existing approaches focus on registering unimodal volumetric data; however, given the increasing interest in the marmoset model for neuroscience research and the importance of addressing individual brain architecture variations, new algorithms are necessary to cross-register multimodal data sets including MRIs and multiple histological series. Here we present a computational approach for same-subject multimodal MRI-guided reconstruction of a series of consecutive histological sections, jointly with diffeomorphic mapping to a reference atlas. We quantify the scale change during different stages of brain histological processing using the Jacobian determinant of the diffeomorphic transformations involved. By mapping the final image stacks to the ex-vivo post-fixation MRI, we show that (a) tape-transfer assisted histological sections can be reassembled accurately into 3D volumes with a local scale change of 2.0 ± 0.4% per axis dimension; in contrast, (b) tissue perfusion/fixation as assessed by mapping the in-vivo MRIs to the ex-vivo post fixation MRIs shows a larger median absolute scale change of 6.9 ± 2.1% per axis dimension. This is the first systematic quantification of local metric distortions associated with whole-brain histological processing, and we expect that the results will generalize to other species. These local scale changes will be important for computing local properties to create reference brain maps.

Wilms' tumor (WT1) (±KTS) variants decreases the progesterone secretion of bovine ovarian theca cells.

Wilms' tumor gene WT1 encodes a nuclear transcriptional factor, which has been shown to regulate granulosa cell steroidogenesis in bovine; however, it is not known whether the functions of theca cells are regulated by WT1. Here, we determined the effects of this gene on theca cell proliferation, apoptosis, and steroidogenesis in vitro. In cultured bovine theca cells, the downregulation of WT1 increased the secretion of progesterone but had no effect on proliferation and apoptosis. WT1 includes the variants WT1(+KTS) and WT1(-KTS), which differ by 3 amino acids KTS (lysine, threonine, and serine). WT1(±KTS) upregulation increased the messenger RNA (mRNA) expression of STAR and CYP17A1 and decreased the progesterone secretion and CYP11A1 mRNA expression. In contrast to WT1(+KTS), WT1(-KTS) upregulation also decreased the mRNA expression of 3ß-HSD. In both variants, WT1(-KTS) has more obvious effects. In conclusion, WT1 can decrease progesterone secretion, likely due in part to the inhibition of CYP11A1 and 3ß-HSD.

Field evaporation and atom probe tomography of pure water tips.

Measuring biological samples by atom probe tomography (APT) in their natural environment, i.e. aqueous solution, would take this analytical method, which is currently well established for metals, semi-conductive materials and non-metals, to a new level. It would give information about the 3D chemical structure of biological systems, which could enable unprecedented insights into biological systems and processes, such as virus protein interactions. For this future aim, we present as a first essential step the APT analysis of pure water (Milli-Q) which is the main component of biological systems. After Cryo-preparation, nanometric water tips are field evaporated with assistance by short laser pulses. The obtained data sets of several tens of millions of atoms reveal a complex evaporation behavior. Understanding the field evaporation process of water is fundamental for the measurement of more complex biological systems. For the identification of the individual signals in the mass spectrum, DFT calculations were performed to prove the stability of the detected molecules.

Thermal and Quantum Melting Phase Diagrams for a Magnetic-Field-Induced Wigner Solid.

A sufficiently large perpendicular magnetic field quenches the kinetic (Fermi) energy of an interacting two-dimensional (2D) system of fermions, making them susceptible to the formation of a Wigner solid (WS) phase in which the charged carriers organize themselves in a periodic array in order to minimize their Coulomb repulsion energy. In low-disorder 2D electron systems confined to modulation-doped GaAs heterostructures, signatures of a magnetic-field-induced WS appear at low temperatures and very small Landau level filling factors (ν≃1/5). In dilute GaAs 2D hole systems, on the other hand, thanks to the larger hole effective mass and the ensuing Landau level mixing, the WS forms at relatively higher fillings (ν≃1/3). Here we report our measurements of the fundamental temperature vs filling phase diagram for the 2D holes' WS-liquid thermal melting. Moreover, via changing the 2D hole density, we also probe their Landau level mixing vs filling WS-liquid quantum melting phase diagram. We find our data to be in good agreement with the results of very recent calculations, although intriguing subtleties remain.

[Clinical characteristics and outcomes of 112 cardiovascular disease patients infected by 2019-nCoV].

Objective: To explore the clinical characteristics and prognosis of the new coronavirus 2019-nCoV patients combined with cardiovascular disease （CVD). Methods: A retrospective analysis was performed on 112 COVID-19 patients with CVD admitted to the western district of Union Hospital in Wuhan, from January 20, 2020 to February 15, 2020. They were divided into critical group (ICU, n=16) and general group (n=96) according to the severity of the disease and patients were followed up to the clinical endpoint. The observation indicators included total blood count, C-reactive protein (CRP), arterial blood gas analysis, myocardial injury markers, coagulation function, liver and kidney function, electrolyte, procalcitonin (PCT), B-type natriuretic peptide (BNP), blood lipid, pulmonary CT and pathogen detection. Results: Compared with the general group, the lymphocyte count (0.74 (0.34, 0.94)×109/L vs. 0.99 (0.71, 1.29)×109/L, P=0.03) was extremely lower in the critical group, CRP (106.98 (81.57, 135.76) mg/L vs. 34.34 (9.55,76.54) mg/L, P<0.001) and PCT (0.20 (0.15,0.48) µg/L vs. 0.11 (0.06,0.20) µg/L, P<0.001) were significantly higher in the critical group. The BMI of the critical group was significantly higher than that of the general group (25.5 (23.0, 27.5) kg/m2 vs. 22.0 (20.0, 24.0) kg/m2，P=0.003). Patients were further divided into non-survivor group (17, 15.18%) group and survivor group (95, 84.82%). Among the non-survivors, there were 88.24% (15/17) patients with BMI> 25.0 kg/m2, which was significantly higher than that of survivors (18.95% (18/95), P<0.001). Compared with the survived patients, oxygenation index (130 (102, 415) vs. 434 (410, 444), P<0.001) was significantly lower and lactic acid (1.70 (1.30, 3.00) mmol/L vs. 1.20 (1.10, 1.60) mmol/L, P<0.001) was significantly higher in the non-survivors. There was no significant difference in the proportion of ACEI/ARB medication between the critical group and the general group or between non-survivors and survivors （all P>0.05). Conclusion: COVID-19 patients combined with CVD are associated with a higher risk of mortality. Critical patients are characterized with lower lymphocyte counts. Higher BMI are more often seen in critical patients and non-survivor. ACEI/ARB use does not affect the morbidity and mortality of COVID-19 combined with CVD. Aggravating causes of death include fulminant inflammation, lactic acid accumulation and thrombotic events.

Tunable broadband terahertz polarizer using graphene-metal hybrid metasurface.

We demonstrate an electrically tunable polarizer for terahertz (THz) frequency electromagnetic waves formed from a hybrid graphene-metal metasurface. Broadband (>3 THz) polarization-dependent modulation of THz transmission is demonstrated as a function of the graphene conductivity for various wire grid geometries, each tuned by gating using an overlaid ion gel. We show a strong enhancement of modulation (up to ∼17 times) compared to graphene wire grids in the frequency range of 0.2-2.5 THz upon introduction of the metallic elements. Theoretical calculations, considering both plasmonic coupling and Drude absorption, are in good agreement with our experimental findings.

Increasing the sensitivity of terahertz split ring resonator metamaterials for dielectric sensing by localized substrate etching.

We demonstrate a significant enhancement in the sensitivity of split ring resonator terahertz metamaterial dielectric sensors by the introduction of etched trenches into their inductive-capacitive gap area, both through finite element simulations and in experiments performed using terahertz time-domain spectroscopy. The enhanced sensitivity is demonstrated by observation of an increased frequency shift in response to overlaid dielectric material of thicknesses up to 18 µm deposited on to the sensor surface. We show that sensitivity to the dielectric is enhanced by a factor of up to ∼2.7 times by the incorporation of locally etched trenches with a depth of ∼3.4 µm, for example, and discuss the effect of the etching on the electrical properties of the sensors. Our experimental findings are in good agreement with simulations of the sensors obtained using finite element methods.

Negative longitudinal magnetoresistance in gallium arsenide quantum wells.

Negative longitudinal magnetoresistances (NLMRs) have been recently observed in a variety of topological materials and often considered to be associated with Weyl fermions that have a defined chirality. Here we report NLMRs in non-Weyl GaAs quantum wells. In the absence of a magnetic field the quantum wells show a transition from semiconducting-like to metallic behaviour with decreasing temperature. We observe pronounced NLMRs up to 9 Tesla at temperatures above the transition and weak NLMRs in low magnetic fields at temperatures close to the transition and below 5 K. The observed NLMRs show various types of magnetic field behaviour resembling those reported in topological materials. We attribute them to microscopic disorder and use a phenomenological three-resistor model to account for their various features. Our results showcase a contribution of microscopic disorder in the occurrence of unusual phenomena. They may stimulate further work on tuning electronic properties via disorder/defect nano-engineering.

Unidirectional monosynaptic connections from auditory areas to the primary visual cortex in the marmoset monkey.

Until the late twentieth century, it was believed that different sensory modalities were processed by largely independent pathways in the primate cortex, with cross-modal integration only occurring in specialized polysensory areas. This model was challenged by the finding that the peripheral representation of the primary visual cortex (V1) receives monosynaptic connections from areas of the auditory cortex in the macaque. However, auditory projections to V1 have not been reported in other primates. We investigated the existence of direct interconnections between V1 and auditory areas in the marmoset, a New World monkey. Labelled neurons in auditory cortex were observed following 4 out of 10 retrograde tracer injections involving V1. These projections to V1 originated in the caudal subdivisions of auditory cortex (primary auditory cortex, caudal belt and parabelt areas), and targeted parts of V1 that represent parafoveal and peripheral vision. Injections near the representation of the vertical meridian of the visual field labelled few or no cells in auditory cortex. We also placed 8 retrograde tracer injections involving core, belt and parabelt auditory areas, none of which revealed direct projections from V1. These results confirm the existence of a direct, nonreciprocal projection from auditory areas to V1 in a different primate species, which has evolved separately from the macaque for over 30 million years. The essential similarity of these observations between marmoset and macaque indicate that early-stage audiovisual integration is a shared characteristic of primate sensory processing.

Illness representations, pain and physical function in patients with rheumatic disorders: between- and within-person associations.

OBJECTIVES: Rehabilitation for patients with rheumatic diseases improves both illness representations (IR) and clinical outcomes such as pain and physical functioning (PF). However, it is unclear whether IR may affect and, in turn, are affected by pain and PF. In this study, we examined both between-person associations and within-person associations between IR and pain/PF over time on three measurement occasions. Furthermore, cross-lagged relationships were examined. DESIGN AND MAIN OUTCOME MEASURES: This secondary analysis is based on data from N = 186 patients with rheumatic diseases. Data on pain, PF and IR were assessed using self-report questionnaires at the beginning, the end and three months after a 3-week inpatient rehabilitation. METHODS: To separate between- and within-person level, data were analysed using random-intercept cross-lagged panel models. RESULTS: On both the between-person level (r = |0.21| - |0.44|) and the within-person level (r = |0.15| - |0.46|), pain and PF were related to cognitive and emotional IR. In addition, we found within-person bidirectional cross-lagged effects between emotional IR and PF. CONCLUSION: IR show complex relationships with pain and PF. Improving PF might improve subsequent illness-related emotional distress and vice versa.

Erratum: Direct observation of composite fermions and their fully-spin-polarized Fermi sea near ν=5/2 [Phys. Rev. Lett. 120, 256601 (2018)].

This corrects the article DOI: 10.1103/PhysRevLett.120.256601.

Magnetic anisotropy manipulation of the femtosecond laser-excited spin wave modes in full-Heusler Co2Fe1-x Mn x Al films.

Spin-wave dynamics in full-Heusler Co2Fe1-x Mn x Al films have been investigated using all-optical pump-probe magneto-optical polar Kerr spectroscopy. We find magnetic damping and anisotropy can be modulated by composition x. Damon-Eshbach (DE) spin wave occurs only in the samples which present intrinsic magnetic damping and have huge uniaxial magnetic anisotropy, implying that intrinsic magnetic damping and huge uniaxial magnetic anisotropy is the necessary conditions to excite coherent DE spin wave. Kittel spin wave appears in low uniaxial magnetic anisotropic samples and presents extrinsic magnetic damping. Therefore, laser-excited spin-wave modes can be manipulated by magnetic anisotropy, whose physical picture is discussed phenomenologically.

Direct Observation of Composite Fermions and Their Fully-Spin-Polarized Fermi Sea near ν=5/2.

The enigmatic even-denominator fractional quantum Hall state at Landau level filling factor ν=5/2 is arguably the most promising candidate for harboring Majorana quasiparticles with non-Abelian statistics and, thus, of potential use for topological quantum computing. The theoretical description of the ν=5/2 state is generally believed to involve a topological p-wave pairing of fully-spin-polarized composite fermions through their condensation into a non-Abelian Moore-Read Pfaffian state. There is, however, no direct and conclusive experimental evidence for the existence of composite fermions near ν=5/2 or for an underlying fully-spin-polarized Fermi sea. Here, we report the observation of composite fermions very near ν=5/2 through geometric resonance measurements and find that the measured Fermi wave vector provides direct demonstration of a Fermi sea with full spin polarization. This lends crucial credence to the model of 5/2 fractional quantum Hall effect as a topological p-wave paired state of composite fermions.

Clear cell sarcomas of the kidney are characterised by BCOR gene abnormalities, including exon 15 internal tandem duplications and BCOR-CCNB3 gene fusion.

AIMS: Clear cell sarcoma of the kidney (CCSK) is a rare paediatric renal malignant tumour. The majority of CCSKs have internal tandem duplications (ITDs) of the BCOR gene, whereas a minority have the YWHAE-NUTM2 gene fusion. A third 'double-negative' (DN) category comprises CCSKs with neither BCOR ITDs nor YWHAE-NUTM2 fusion. The aim of this study was to characterise 11 histologically diagnosed CCSKs immunohistochemically (with CCND1, BCOR and CCNB3 stains) and genetically. METHODS AND RESULTS: By next-generation sequencing, 10 cases (90.9%) had BCOR exon 15 ITDs, with positive BCOR immunoreactivity being found in four (36%) or eight (72%) cases, depending on the antibody clone. By reverse transcription polymerase chain reaction, none had the YWHAE-NUTM2 fusion. The DN case had a BCOR-CCNB3 fusion and strong nuclear CCNB3 and BCOR immunoreactivity. Quantitative polymerase chain reaction showed markedly elevated BCOR expression in this case, whereas BCOR ITD cases had lower levels of elevated BCOR expression. CONCLUSIONS: The majority of the CCSKs in our cohort had BCOR ITDs, and none had the YWHAE-NUTM2 fusion. We verified the strong, diffuse cyclin D1 (CCND1) immunoreactivity in CCSKs described in recent reports. BCOR immunoreactivity was not consistently positive in all CCSKs with BCOR ITDs, and therefore cannot be used as a diagnostic immunohistochemical stain to identify BCOR ITD cases. The DN case was a BCOR-CCNB3 fusion sarcoma. BCOR-CCNB3 sarcoma is typically a primary bone sarcoma affecting male adolescents, and this is the first report of it presenting in a kidney of a young child as a CCSK. The full spectrum of DN CCSKs awaits more comprehensive characterisation.