Evidence for Band Renormalizations in Strong-Coupling Superconducting Alkali-Fulleride Films.

There has been a long-standing debate about the mechanism of the unusual superconductivity in alkali-intercalated fullerides. In this Letter, using high-resolution angle-resolved photoemission spectroscopy, we systematically investigate the electronic structures of superconducting K_{3}C_{60} thin films. We observe a dispersive energy band crossing the Fermi level with the occupied bandwidth of about 130 meV. The measured band structure shows prominent quasiparticle kinks and a replica band involving the Jahn-Teller active phonon modes, which reflects strong electron-phonon coupling in the system. The electron-phonon coupling constant is estimated to be about 1.2, which dominates the quasiparticle mass renormalization. Moreover, we observe an isotropic nodeless superconducting gap beyond the mean-field estimation (2Δ/k_{B}T_{c}≈5). Both the large electron-phonon coupling constant and large reduced superconducting gap suggest a strong-coupling superconductivity in K_{3}C_{60}, while the electronic correlation effect is suggested by the observation of a waterfall-like band dispersion and the small bandwidth compared with the effective Coulomb interaction. Our results not only directly visualize the crucial band structure but also provide important insights into the mechanism of the unusual superconductivity of fulleride compounds.

Visualization of Chiral Electronic Structure and Anomalous Optical Response in a Material with Chiral Charge Density Waves.

Chiral materials have attracted significant research interests as they exhibit intriguing physical properties, such as chiral optical response, spin-momentum locking, and chiral induced spin selectivity. Recently, layered transition metal dichalcogenide 1T-TaS_{2} has been found to host a chiral charge density wave (CDW) order. Nevertheless, the physical consequences of the chiral order, for example, in electronic structures and the optical properties, are yet to be explored. Here, we report the spectroscopic visualization of an emergent chiral electronic band structure in the CDW phase, characterized by windmill-shaped Fermi surfaces. We uncover a remarkable chirality-dependent circularly polarized Raman response due to the salient in-plane chiral symmetry of CDW, although the ordinary circular dichroism vanishes. Chiral Fermi surfaces and anomalous Raman responses coincide with the CDW transition, proving their lattice origin. Our Letter paves a path to manipulate the chiral electronic and optical properties in two-dimensional materials and explore applications in polarization optics and spintronics.

Polar meron lattice in strained oxide ferroelectrics.

A topological meron features a non-coplanar structure, whose order parameters in the core region are perpendicular to those near the perimeter. A meron is half of a skyrmion, and both have potential applications for information carrying and storage. Although merons and skyrmions in ferromagnetic materials can be readily obtained via inter-spin interactions, their behaviour and even existence in ferroelectric materials are still elusive. Here we observe using electron microscopy not only the atomic morphology of merons with a topological charge of 1/2, but also a periodic meron lattice in ultrathin PbTiO3 films under tensile epitaxial strain on a SmScO3 substrate. Phase-field simulations rationalize the formation of merons for which an epitaxial strain, as a single alterable parameter, plays a critical role in the coupling of lattice and charge. This study suggests that by engineering strain at the nanoscale it should be possible to fabricate topological polar textures, which in turn could facilitate the development of nanoscale ferroelectric devices.

Bypassing the Structural Bottleneck in the Ultrafast Melting of Electronic Order.

Impulsive optical excitation generally results in a complex nonequilibrium electron and lattice dynamics that involves multiple processes on distinct timescales, and a common conception is that for times shorter than about 100 fs the gap in the electronic spectrum is not seriously affected by lattice vibrations. Here, however, by directly monitoring the photoinduced collapse of the spectral gap in a canonical charge-density-wave material, the blue bronze Rb_{0.3}MoO_{3}, we find that ultrafast (∼60 fs) vibrational disordering due to efficient hot-electron energy dissipation quenches the gap significantly faster than the typical structural bottleneck time corresponding to one half-cycle oscillation (∼315 fs) of the coherent charge-density-wave amplitude mode. This result not only demonstrates the importance of incoherent lattice motion in the photoinduced quenching of electronic order, but also resolves the perennial debate about the nature of the spectral gap in a coupled electron-lattice system.

Preventive effects of Polygonum orientale L. on ovariectomy-induced osteoporosis in rats.

Objective: The aim of the present study was to evaluate the effects of ethyl acetate extract of Polygonum orientale L. (POE) on ameliorating postmenopausal osteoporosis in ovariectomized (OVX) rats.Methods: Six-month-old female rats were randomly divided into seven groups: sham-operated; OVX; OVX with estradiol valerate; OVX with alendronate; and OVX with POE in graded doses (3.75, 5.0, or 7.5 g/kg/day). Administration began at week 6 after ovariectomy for 12 weeks. A comprehensive assessment of bone quality was performed, including serum biochemical markers, serum inflammatory factors, bone oxidative stress markers, bone mechanics, and bone histomorphometry.Results: POE treatment significantly decelerated OVX-induced body weight gain without affecting the uterus index and produced a significant decrease in the levels of serum bone turnover markers (p < 0.05 or p < 0.01). Biomechanical testing demonstrated that POE (5.0 and 7.5 g/kg/day) treatments significantly prevented the reduction in maximum stress and Young's modulus in OVX rats (p < 0.05). Compared with the OVX group, POE (3.75, 5.0, or 7.5 g/kg/day) treatments significantly increased trabecular bone mineral density by 35.03, 38.42, and 42.02%, respectively.Conclusion: Our findings suggest that POE has potential effects in regulation of bone metabolism and prevention of bone loss in postmenopausal osteoporosis.

[Efficacy and safety of active transfer of plaque versus provisional stenting with drug-eluting stents for the treatment of coronary bifurcation lesions].

Objective: To compare the efficacy and safety of active transfer of plaque (ATP) versus provisional stenting (PS) with drug-eluting stents (DES) for the treatment of coronary bifurcation lesions. Methods: A total of 1 136 patients with bifurcation lesions hospitalized in 6 selected hospitals between January 2010 and January 2014 were included in this prospective observational trial, patients were divided into either ATP (n=560) or PS group (n=576) accordingly. The primary endpoint was target lesion revascularization within 1 year, and the second endpoints were all-cause death, cardiogenic death, myocardial infarction, stent thrombosis, stroke, recurrent angina within 1 year. Results: There were no significant differences in age, sex, hypertension, diabetes, hyperlipidemia and smoking history between the two groups (P>0.05). The incidence of TIMI blood flow <3 grade in the side branch (1.6%(9/560) vs. 7.5% (43/576), P<0.01), acute occlusion of the side branch (1.3%(7/560) vs. 7.1%(41/576), P<0.01) and implanted stents of side branch (1.8%(10/560) vs. 7.8% (45/576), P<0.01) were significantly lower in the ATP group than those in the PS group. During the one year follow up, the rate of target lesion revascularization was similar between ATP group and PS group (4.6%(26/560) vs. 4.0%(23/576), P=0.66). Conclusions: The effectiveness and safetyof ATP techniquein the patients with coronary bifurcation lesions is comparable to the PS technique. However, ATP technique is superior to PS technique on effectively reducing the incidence of implanted stents in the side branch.

[Trends of in-hospital mortality and constituent ratio of patients with acute myocardial infarction].

Objective: To analyze the trends on constituent ratio of non-ST-segment-elevation (NSTEMI) and ST-segment-elevation myocardial infarction (STEMI) and related in-hospital mortality in acute myocardial infarction (AMI) patients hospitalized in Beijing Anzhen Hospital from 2004 to 2014. Methods: This is a single-center, retrospective study. We reviewed all patients hospitalized for AMI in Beijing Anzhen Hospital from January 1 2004 to December 31 2014, and collected all related information including hospitalization stay, the type of AMI, revascularization and in-hospital mortality. We analyzed the trends of constituent ratio of NSTEMI and STEMI, and their in-hospital mortalities during the 11 years. Results: Data from a total of 23 864 patients with AMI, including 5 539 STEMI and 18 325 NSTEMI, were analyzed. Compared with STEMI patients, NSTEMI patients were older, less likely to be male (P<0.001), had higher prevalence of hypertension, hyperlipidemia, diabetes (P<0.001), and lower prevalence of smoking (P<0.001). Additionally, patients with NSTEMI were more likely to have prior history of MI (12.6% (695/5 539) vs. 7.4% (1 354/18 325), P<0.001) and coronary artery bypass graft surgery (2.7% (152/5 539) vs. 0.7% (124/18 325), P<0.001). The constituent ratio of NSTEMI was significantly increased during the observation period, rising from 15.8% (107/802) in 2004 to 35.7% (1 273/3 583) in 2014 (P value for trend <0.001). The in-hospital mortality of NSTEMI patients was significantly lower compared with those with STEMI (1.84% (102 cases) vs. 2.74% (502 cases), P<0.001). The mortality of both STEMI and NSTEMI were significantly decreased during the 11 years (both P value for χ(2) trend test <0.001). After adjusting for other risk factors, NSTEMI was independently associated with lower in-hospital mortality (OR=0.50, 95%CI 0.40-0.63, P<0.001). Conclusions: In patients with AMI, the constituent ratio of NSTEMI versus STEMI is increased during the 11 years. The in-hospital mortality is decreased for both STEMI and NSTEMI patients in the past 11 years, and the in-hospital mortality rate of NSTEMI patients is lower than STEMI patients in this patient cohort during the observation period.

Evolution of the Fermi surface of Weyl semimetals in the transition metal pnictide family.

Topological Weyl semimetals (TWSs) represent a novel state of topological quantum matter which not only possesses Weyl fermions (massless chiral particles that can be viewed as magnetic monopoles in momentum space) in the bulk and unique Fermi arcs generated by topological surface states, but also exhibits appealing physical properties such as extremely large magnetoresistance and ultra-high carrier mobility. Here, by performing angle-resolved photoemission spectroscopy (ARPES) on NbP and TaP, we directly observed their band structures with characteristic Fermi arcs of TWSs. Furthermore, by systematically investigating NbP, TaP and TaAs from the same transition metal monopnictide family, we discovered their Fermiology evolution with spin-orbit coupling (SOC) strength. Our experimental findings not only reveal the mechanism to realize and fine-tune the electronic structures of TWSs, but also provide a rich material base for exploring many exotic physical phenomena (for example, chiral magnetic effects, negative magnetoresistance, and the quantum anomalous Hall effect) and novel future applications.

[The role of four criteria in assessment of the severity and prognosis of hyperlipidemic acute pancreatitis].

OBJECTIVE: To explore the four criteria, including bedside index for severity in acute pancreatitis(BISAP), Ranson score, modified CT severity index(MCTSI) and acute physiology and chronic health evaluation scoring systemⅡ(APACHE Ⅱ) in assessment of severity and prognosis of hyperlipidemic acute pancreatitis. METHODS: A total of 326 patients with hyperlipidemic acute pancreatitis were studied retrospectively from August 2006 to July 2015. The discrepancy of the four criteria in assessment of severity and prognosis of hyperlipidemic acute pancreatitis was compared with chi-square test and receiver operating characteristic curve. RESULTS: The incidences of moderately severe acute pancreatitis and severe acute pancreatitis, local complications and mortality of patients with BISAP score≥3, Ranson score≥3, APACHE Ⅱ score≥8 and MCTSI score≥4 were significantly higher than BISAP score<3, Ranson score<3, APACHE Ⅱscore<8 and MCTSI<4 respectively (all P<0.05). As far as severity was concerned, the sensitivity and AUC of APACHEⅡ were 57% and 0.814, which were higher than the other systems. The second most sensitive criterion was BISAP. In assessment of local complications, the sensitivity and AUC of MCTSI were 68% and 0.791, which were higher than the other three. The most sensitive criterion to predict mortality was BISAP with sensitivity 89% and AUC 0.867, which was followed by APACHE Ⅱ. CONCLUSIONS: All four criteria can be used to determine the severity, local complications and mortality. Generally, BISAP is simple and easy to practice, and better than the other three.

[Role of ORAI1 in the balloon injury-induced rat carotid artery neointimal formation and the relationship between ORAI1 and sodium and calcium exchange 1].

Objective: To investigate the role of ORAI1 in the balloon injury-induced rat carotid artery neointimal formation and the relationship between ORAI1 and sodium and calcium exchanger(NCX)1. Methods: According to condition of carotid artery balloon injury and observation time, Sprague Dawley rats were divided into 3 groups including sham group, 7 days injury group, and 14 day injury group(n=3 each). According to virus of transfection, Sprague Dawley rats were divided into 2 groups including negative control group (negative lentiviruses particles transfection after establishment of carotid artery balloon injury model, n=3) and siORAI1 group(siORAI1 transfection after operation, n=3). Carotid artery neointimal formation was analyzed after HE staining. The ORAI mRNA expression level was detected using real-time PCR. The proliferating cell nuclear antigen (PCNA), ORAI and NCX1 protein expression level were measured by Western blot. Results: (1) Carotid artery intima was significantly thicker in 7 days and 14 days injury group than in sham group((0.54±0.11)µm2 and (0.89±0.12)µm2 vs.(0.11±0.08)µm2, both P<0.05). Relative expression level of PCNA protein was significantly higher in 7 days and 14 days injury group than in sham group(1.43±0.16 and 1.95±0.16 vs. 1, both P<0.05). Relative mRNA expression level of ORAI1 (1.39±0.14 and 1.78±0.21 vs. 0.56±0.09, both P<0.05) and protein expression level (1.42±0.19 and 1.78±0.22 vs. 1, both P<0.05) were significantly higher in 7 days and 14 days injury group than in sham group.(2) After 14 days, relative expression level of ORAI1 protein was significantly lower in siORAI1 group than in negative control group (0.21±0.161, P<0.05). Carotid artery intima thickness was significantly reduced in siORAI1 group compared to negative control group((0.19±0.14)µm2 vs.(0.91±0.23)µm2,P<0.05). Relative expression level of NCX1 protein was also significantly lower in siORAI1 group than in negative control group(0.53±0.131, P<0.05). Conclusions: ORAI1 may play a key role in the balloon injury-induced neointimal formation and vascular smooth muscle cells proliferation in rat carotid artery.ORAI1 knockdown could down regulate the NCX1 expression and attenuate the balloon injury-induced neointimal formation and vascular smooth muscle cells proliferation in rat carotid artery.

Pressure-induced superconductivity in topological parent compound Bi2Te3.

We report a successful observation of pressure-induced superconductivity in a topological compound Bi(2)Te(3) with T(c) of ∼3 K between 3 to 6 GPa. The combined high-pressure structure investigations with synchrotron radiation indicated that the superconductivity occurred at the ambient phase without crystal structure phase transition. The Hall effects measurements indicated the hole-type carrier in the pressure-induced superconducting Bi(2)Te(3) single crystal. Consequently, the first-principles calculations based on the structural data obtained by the Rietveld refinement of X-ray diffraction patterns at high pressure showed that the electronic structure under pressure remained topologically nontrivial. The results suggested that topological superconductivity can be realized in Bi(2)Te(3) due to the proximity effect between superconducting bulk states and Dirac-type surface states. We also discuss the possibility that the bulk state could be a topological superconductor.

[Efficacy and prognostic factors of allogeneic hematopoietic stem cell transplantation in the treatment of secondary acute myeloid leukemia].

Objective: To evaluate the efficacy and prognostic factors of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with secondary acute myeloid leukemia (sAML) . Methods: In this multicenter, retrospective clinical study, adult patients aged ≥18 years who underwent allo-HSCT for sAML at four centers of the Zhejiang Hematopoietic Stem Cell Transplantation Collaborative Group from January 2014 to November 2022 were included, and the efficacy and prognostic factors of allo-HSCT were analyzed. Results: A total of 95 patients were enrolled; 66 (69.5%) had myelodysplastic syndrome-acute myeloid leukemia (MDS-AML) , 4 (4.2%) had MDS/MPN-AML, and 25 (26.3%) had therapy-related AML (tAML) . The 3-year CIR, LFS, and overall survival (OS) rates were 18.6% (95% CI 10.2%-27.0%) , 70.6% (95% CI 60.8%-80.4%) , and 73.3% (95% CI 63.9%-82.7%) , respectively. The 3-year CIRs of the M-AML group (including MDS-AML and MDS/MPN-AML) and the tAML group were 20.0% and 16.4%, respectively (P=0.430) . The 3-year LFSs were 68.3% and 75.4%, respectively (P=0.176) . The 3-year OS rates were 69.7% and 75.4%, respectively (P=0.233) . The 3-year CIRs of the groups with and without TP53 mutations were 60.0% and 13.7%, respectively (P=0.003) ; the 3-year LFSs were 20.0% and 76.5%, respectively (P=0.002) ; and the 3-year OS rates were 40.0% and 77.6%, respectively (P=0.002) . According to European LeukmiaNet 2022 (ELN2022) risk stratification, the 3-year CIRs of patients in the low-, intermediate-, and high-risk groups were 8.3%, 17.8%, and 22.6%, respectively (P=0.639) . The three-year LFSs were 91.7%, 69.5%, and 65.6%, respectively (P=0.268) . The 3-year OS rates were 91.7%, 71.4%, and 70.1%, respectively (P=0.314) . Multivariate analysis revealed that advanced disease at allo-HSCT and TP53 mutations were independent risk factors for CIR, LFS, and OS. Conclusion: There was no significant difference in the prognosis of patients who underwent allo-HSCT among the MDS-AML, MDS/MPN-AML, and tAML groups. Advanced disease at transplantation and TP53 mutations were poor prognostic factors. ELN2022 risk stratification had limited value for predicting the prognosis of patients with sAML following allo-HSCT.

VCP gene variation predicts outcome of advanced non-small-cell lung cancer platinum-based chemotherapy.

Valosin-containing protein (VCP), or p97, is a member of the ATP-binding protein family, and is involved in numerous cellular events, such as, protein degradation, membrane fusion, and chaperone activity. VCP has been demonstrated playing a critical role in non-small-cell lung cancer (NSCLC) pathogenesis and progression recently. We investigated the association between VCP polymorphisms and clinical outcome in advanced NSCLC patients undergoing platinum-based chemotherapy. We recruited 663 Chinese advanced NSCLC patients who were treated with platinum-based regimens, and using their clinical data, we assessed the efficacy and side effects of their treatment. Three tag-single nucleotide polymorphisms (SNPs) of VCP were genotyped. SNP rs2074549 showed a significant association with severe neutropenia. Its G/G genotype increased the risk of grade 3 or 4 neutropenia compared with wild-type homozygotes A/A (P = .001, odds ratio = 2.975). Haplotype association analysis revealed that CGA was associated with the increased incidence of severe neutropenia (P = .041, odds ratio = 1.439). However, no significant relationship was found between the presence of VCP polymorphisms and treatment efficacy when objective response, progression-free survival, and overall survival (OS) were evaluated. Our study is the first to provide evidence that VCP polymorphisms are associated with a severe chemotherapy-related adverse outcome in platinum-treated advanced NSCLC patients.

Activation of proacrosin accompanies upregulation of sp32 protein tyrosine phosphorylation in pig sperm.

This study investigated the relationship between acrosin activation and pig sperm proacrosin binding protein (sp32) phosphorylation levels. Differently processed pig spermatozoa (fresh semen sperm, capacitation sperm, acrosome reaction sperm, capacitation-like sperm, and thawed sperm) were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blot analysis. The fresh semen and capacitation sperm groups both produced proacrosin protein bands of 55 kDa; however, the result of the fresh semen sperm group was clearer than that of the capacitation sperm group. The thawed sperm group showed a shallow strip at 55 kDa. The capacitation and acrosome reaction sperm groups produced obvious proacrosin protein bands at 35 kDa, and the strips of the capacitation sperm group were again clearer. A faint band was visible at 32 kDa in the acrosome reaction sperm group. The capacitation, thawed, and acrosome reaction sperm groups showed significant strips in sp32, and the bands of the acrosome reaction sperm group were shallower than those of the 2 other groups. The capacitation and thawed sperm groups produced significant strips at 40 kDa, and the capacitation sperm group produced an additional strip at 55 kDa. In conclusion, sp32 phosphorylation levels can promote proacrosin activation into the active acrosin.

Development of a laser-based angle-resolved-photoemission spectrometer with sub-micrometer spatial resolution and high-efficiency spin detection.

Angle-resolved photoemission spectroscopy with sub-micrometer spatial resolution (µ-ARPES), has become a powerful tool for studying quantum materials. To achieve sub-micrometer or even nanometer-scale spatial resolution, it is important to focus the incident light beam (usually from synchrotron radiation) using x-ray optics, such as the zone plate or ellipsoidal capillary mirrors. Recently, we developed a laser-based µ-ARPES with spin-resolution (LMS-ARPES). The 177 nm laser beam is achieved by frequency-doubling a 355 nm beam using a KBBF crystal and subsequently focused using an optical lens with a focal length of about 16 mm. By characterizing the focused spot size using different methods and performing spatial-scanning photoemission measurement, we confirm the sub-micron spatial resolution of the system. Compared with the µ-ARPES facilities based on the synchrotron radiation, our LMS-ARPES system is not only more economical and convenient, but also with higher photon flux (>5 × 1013 photons/s), thus enabling the high-resolution and high-statistics measurements. Moreover, the system is equipped with a two-dimensional spin detector based on exchange scattering at a surface-passivated iron film grown on a W(100) substrate. We investigate the spin structure of the prototype topological insulator Bi2Se3 and reveal a high spin-polarization rate, confirming its spin-momentum locking property. This lab-based LMS-ARPES will be a powerful research tool for studying the local fine electronic structures of different condensed matter systems, including topological quantum materials, mesoscopic materials and structures, and phase-separated materials.

Nodeless superconducting gap in A(x)Fe2Se2 (A=K,Cs) revealed by angle-resolved photoemission spectroscopy.

Pairing symmetry is a fundamental property that characterizes a superconductor. For the iron-based high-temperature superconductors, an s(±)-wave pairing symmetry has received increasing experimental and theoretical support. More specifically, the superconducting order parameter is an isotropic s-wave type around a particular Fermi surface, but it has opposite signs between the hole Fermi surfaces at the zone centre and the electron Fermi surfaces at the zone corners. Here we report the low-energy electronic structure of the newly discovered superconductors, A(x)Fe(2)Se(2) (A=K,Cs) with a superconducting transition temperature (Tc) of about 30 K. We found A(x)Fe(2)Se(2) (A=K,Cs) is the most heavily electron-doped among all iron-based superconductors. Large electron Fermi surfaces are observed around the zone corners, with an almost isotropic superconducting gap of ~10.3 meV, whereas there is no hole Fermi surface near the zone centre, which demonstrates that interband scattering or Fermi surface nesting is not a necessary ingredient for the unconventional superconductivity in iron-based superconductors. Thus, the sign change in the s(±) pairing symmetry driven by the interband scattering as suggested in many weak coupling theories becomes conceptually irrelevant in describing the superconducting state here. A more conventional s-wave pairing is probably a better description.

Enhanced corrosion resistance by engineering crystallography on metals.

Nanometer-thick passive films, which impart superior corrosion resistance to metals, are degraded in long-term service; they are also susceptible to chloride-induced localized attack. Here we show, by engineering crystallographic configurations upon metal matrices adjacent to their passive films, we obtain great enhancement of corrosion resistance of FeCr15Ni15 single crystal in sulphuric acid, with activation time up to two orders of magnitude longer than that of the non-engineered counterparts. Meanwhile, engineering crystallography decreases the passive current density and shifts the pitting potential to noble values. Applying anodic polarizations under a transpassivation potential, we make the metal matrices underneath the transpassive films highly uneven with {111}-terminated configurations, which is responsible for the enhancement of corrosion resistance. The transpassivation strategy also works in the commercial stainless steels where both grain interior and grain boundaries are rebuilt into the low-energy configurations. Our results demonstrate a technological implication in the pretreatment process of anti-corrosion engineering.