Evidence of superconducting Fermi arcs.

An essential ingredient for the production of Majorana fermions for use in quantum computing is topological superconductivity1,2. As bulk topological superconductors remain elusive, the most promising approaches exploit proximity-induced superconductivity3, making systems fragile and difficult to realize4-7. Due to their intrinsic topology8, Weyl semimetals are also potential candidates1,2, but have always been connected with bulk superconductivity, leaving the possibility of intrinsic superconductivity of their topological surface states, the Fermi arcs, practically without attention, even from the theory side. Here, by means of angle-resolved photoemission spectroscopy and ab initio calculations, we identify topological Fermi arcs on two opposing surfaces of the non-centrosymmetric Weyl material trigonal PtBi2 (ref. 9). We show these states become superconducting at temperatures around 10 K. Remarkably, the corresponding coherence peaks appear as the strongest and sharpest excitations ever detected by photoemission from solids. Our findings indicate that superconductivity in PtBi2 can occur exclusively at the surface, rendering it a possible platform to host Majorana modes in intrinsically topological superconductor-normal metal-superconductor Josephson junctions.

Emergence of Fermi arcs due to magnetic splitting in an antiferromagnet.

The Fermi surface plays an important role in controlling the electronic, transport and thermodynamic properties of materials. As the Fermi surface consists of closed contours in the momentum space for well-defined energy bands, disconnected sections known as Fermi arcs can be signatures of unusual electronic states, such as a pseudogap1. Another way to obtain Fermi arcs is to break either the time-reversal symmetry2 or the inversion symmetry3 of a three-dimensional Dirac semimetal, which results in formation of pairs of Weyl nodes that have opposite chirality4, and their projections are connected by Fermi arcs at the bulk boundary3,5-12. Here, we present experimental evidence that pairs of hole- and electron-like Fermi arcs emerge below the Neel temperature (TN) in the antiferromagnetic state of cubic NdBi due to a new magnetic splitting effect. The observed magnetic splitting is unusual, as it creates bands of opposing curvature, which change with temperature and follow the antiferromagnetic order parameter. This is different from previous theoretically considered13,14 and experimentally reported cases15,16 of magnetic splitting, such as traditional Zeeman and Rashba, in which the curvature of the bands is preserved. Therefore, our findings demonstrate a type of magnetic band splitting in the presence of a long-range antiferromagnetic order that is not readily explained by existing theoretical ideas.

Charge-Density-Wave-Induced Peak-Dip-Hump Structure and the Multiband Superconductivity in a Kagome Superconductor CsV_{3}Sb_{5}.

The entanglement of charge density wave (CDW), superconductivity, and topologically nontrivial electronic structure has recently been discovered in the kagome metal AV_{3}Sb_{5} (A=K, Rb, Cs) family. With high-resolution angle-resolved photoemission spectroscopy, we study the electronic properties of CDW and superconductivity in CsV_{3}Sb_{5}. The spectra around K[over ¯] is found to exhibit a peak-dip-hump structure associated with two separate branches of dispersion, demonstrating the isotropic CDW gap opening below E_{F}. The peak-dip-hump line shape is contributed by linearly dispersive Dirac bands in the lower branch and a dispersionless flat band close to E_{F} in the upper branch. The electronic instability via Fermi surface nesting could play a role in determining these CDW-related features. The superconducting gap of ∼0.4 meV is observed on both the electron band around Γ[over ¯] and the flat band around K[over ¯], implying the multiband superconductivity. The finite density of states at E_{F} in the CDW phase is most likely in favor of the emergence of multiband superconductivity, particularly the enhanced density of states associated with the flat band. Our results not only shed light on the controversial origin of the CDW, but also offer insights into the relationship between CDW and superconductivity.

Weekly versus triweekly cisplatin-alone adjuvant chemoradiotherapy after radical hysterectomy for stages IB-IIA cervical cancer with risk of recurrence.

Weekly and triweekly cisplatin-alone concomitant chemoradiotherapy regimens after radical surgery were compared in stages IB-IIA cervical cancer with intermediate- or high-risk factors to identify the better therapeutic regimen. We retrospectively analyzed patients with stages IB-IIA cervical cancer who received radical hysterectomy followed by concurrent adjuvant chemoradiotherapy to compare the efficiency between weekly and triweekly regimen groups. We evaluated between-group differences in survival, recurrence, compliance, and adverse effects. A total of 217 patients were included in this study (triweekly group vs. weekly group; 97 vs. 120). The mean follow-up was 47.2 months. The 5-year disease-free survival (DFS) was 84.4% or 76.5% for patients treated with triweekly cisplatin chemotherapy or the weekly regimen, respectively (P = 0.110). The 5-year overall survival (OS) was 82.4 and 78.6% for the same treatment groups, respectively (P = 0.540). The DFS of the patients with pelvic lymph node metastasis were marginally better in triweekly regimen group compared with the weekly group (P = 0.031). Grades 3-4 leukopenia was significantly more common in the triweekly group (P = 0.028). The weekly cisplatin chemotherapy group experienced the same therapeutic effect as the triweekly cisplatin-alone chemotherapy group but with less toxicity. However, triweekly cisplatin regimen reduced the recurrence in patients with pelvic lymph node metastasis.

A nano-detection system based on a chemical probe for early diagnosis of atherosclerosis in situ.

With the existing medical diagnostic technology, the diagnosis of atherosclerosis (AS) is mainly focused on the later stage of AS development rather than plaque imaging in the period before plaque formation. It is impractical to apply the existing theoretical methods for the purpose of early detection of AS. Herein, this study uses a naphthalimide-based fluorescent probe for recognition of cellular reactive oxygen species (ROS). A platelet membrane (Mp) with foam cell targeting was wrapped around the probes to prepare two vesicle structures TBNG@Mp and GNTB@Mp. The animal experiment results show that the screened nano-detection system TBNG@Mp could accumulate in the thoracic aorta of early AS rats. Under the effect of intracellular ROS, fluorescence signals can be observed. In addition, acute biological toxicity was not observed in pathological sections. Therefore, the foam cell targeting system TBNG@Mp with acceptable biocompatibility can realize the detection of AS one to two decades in advance as well as has a good application prospect.

ROS-boosted photodynamic therapy against metastatic melanoma by inhibiting the activity of antioxidase and oxygen-producing nano-dopants.

The antioxidant effect weakens the ability of PDT to resist melanoma, and the hypoxic tumor environment further restricts the application of photosensitizers in tumors. Therefore, to enhance the ability of PDT to resist melanoma, we designed a sequential enhanced PDT theranostic platform (Au@MTM-HA). Firstly, the nanotherapeutic platform uses TiO2 as a photosensitizer, which is doped with MnO2 to form a mesoporous MTM. The MTM can continuously provide oxygen, thereby increasing the level of reactive oxygen species (ROS) and reducing the metastatic effect by alleviating tumor hypoxia. Furthermore, the released Au25Sv9 could inhibit the activity of antioxidant defense enzymes and reduce the scavenging of ROS and further enhance the PDT effect. Simultaneously, surface-modified HA could not only recognize CD44 receptor but also act as a sealing agent for carriers. Result: Au@MTM-HA could explosively produce a 3-fold higher ROS and improve the PDT effect. Therefore, this work may provide strong evidence for Au@MTM-HA as a new and promising PDT candidate for the treatment of metastatic melanoma.

Liver X receptor agonist T0901317 inhibits the migration and invasion of non-small-cell lung cancer cells in vivo and in vitro.

Liver X receptors are recognized as important regulators of cholesterol, fatty acid metabolism, inflammatory responses, and glucose homeostasis. The antineoplastic properties of synthetic liver X receptor (LXR) agonists (T0901317 and GW3965) have been reported in human carcinomas. Epidermal growth factor tyrosine kinase inhibitor (EGFR-TKI) is a first-line treatment for non-small-cell lung cancer patients with EGFR mutations. We used scratch and transwell assays to analyze cell migration and invasion. We evaluated tumor migration and invasion in vitro using a fluorescent orthotopic lung cancer model. An MMP9 (mouse) enzyme-linked immunosorbent assay kit was used to measure serum MMP9 concentrations. Protein expression was identified by western blot assays. In this study, we determined the effects of T0901317 and/or an EGFR-TKI on the lung cancer cell lines A549 and HCC827-8-1 in vitro and in vivo. We confirmed that the combination of the LXR agonist T0901317 and gefitinib can inhibit the migration and invasion of lung cancer both in vivo and in vitro, and this effect was possibly achieved by the inhibition of the ERK/MAPK signaling pathway. Our study showed that the combination of the LXR agonist T0901317 and gefitinib can inhibit the migration and invasion of lung cancer both in vivo and in vitro.

PPARγ agonist efatutazone and gefitinib synergistically inhibit the proliferation of EGFR-TKI-resistant lung adenocarcinoma cells via the PPARγ/PTEN/Akt pathway.

Development of acquired resistance to EGFR-TKI therapy continues to be a serious clinical problem in Lung adenocarcinoma management. Peroxisome proliferator-activated receptor gamma (PPARγ) agonists demonstrate anti-tumor activity likely via transactivating genes that regulate cell proliferation, differentiation and apoptosis. Efatutazone, a novel later generation PPARγ agonist, selectively activates PPARγ target genes and has antiproliferative effects in a range of malignancies. However, the exact function and molecular mechanism of PPARγ agonists efatutazone in EGFR-TKI gefitinib-resistance of Lung adenocarcinoma has not been determined. In this study, we studied the development of acquired resistance to an EGFR-TKI gefitinib in lung adenocarcinoma cells and investigated the antiproliferative effects of efatutazone in the acquired resistant cells. The treatment of gefitinib-resistant cells with efatutazone reduced the growth of gefitinib-resistant cells in a dose- and time-dependent manner, and facilitated the anti-proliferative effects of gefitinib. Mechanistic investigations suggested that efatutazone acted by upregulating protein expression of PPARγ, phosphatase and tensin homolog (PTEN), inactivating the Akt pathway, followed by dephosphorylation of p21Cip1 at Thr145 without affecting the transcriptional levels. Our results suggested that efatutazone, alone or in combination with gefitinib, might offer therapeutic effects in lung adenocarcinoma.

Deep Eutectic Solvents (DESs) for the Isolation of Willow Lignin (Salix matsudana cv. Zhuliu).

Deep eutectic solvents (DESs) are a potentially high-value lignin extraction methodology. DESs prepared from choline chloride (ChCl) and three hydrogen-bond donors (HBD)-lactic acid (Lac), glycerol, and urea-were evaluated for isolation of willow (Salix matsudana cv. Zhuliu) lignin. DESs types, mole ratio of ChCl to HBD, extraction temperature, and time on the fractionated DES-lignin yield demonstrated that the optimal DES-lignin yield (91.8 wt % based on the initial lignin in willow) with high purity of 94.5% can be reached at a ChCl-to-Lac molar ratio of 1:10, extraction temperature of 120 °C, and time of 12 h. Fourier transform infrared spectroscopy (FT-IR) , 13C-NMR, and 31P-NMR showed that willow lignin extracted by ChCl-Lac was mainly composed of syringyl and guaiacyl units. Serendipitously, a majority of the glucan in willow was preserved after ChCl-Lac treatment.

Immunomodulation effects of mesenchymal stromal cells on acute graft-versus-host disease after hematopoietic stem cell transplantation.

Refractory acute graft-versus-host disease (aGVHD) is a major cause of death after allogeneic hematopoietic stem cell transplantation. This study evaluated the immunomodulation effects of mesenchymal stromal cells (MSCs) from bone marrow of a third-party donor for refractory aGVHD. Forty-seven patients with refractory aGVHD were enrolled: 28 patients receiving MSC and 19 patients without MSC treatment. MSCs were given at a median dose of 1 × 10(6) cells/kg weekly until patients got complete response or received 8 doses of MSCs. After 125 doses of MSCs were administered, with a median of 4 doses (range, 2 to 8) per patient, overall response rate was 75% in the MSC group compared with 42.1% in the non-MSC group (P = .023). The incidence of cytomegalovirus, Epstein-Barr virus infections, and tumor relapse was not different between the 2 groups during aGVHD treatment and follow-up. The incidence and severity of chronic GVHD in the MSC group were lower than those in the non-MSC group (P = .045 and P = .005). The ratio of CD3(+)CD4(+)/CD3(+)CD8(+) T cells, the frequencies of CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs), and the levels of signal joint T cell-receptor excision DNA circles (sjTRECs) after MSCs treatment were higher than those pretreatment. MSC-treated patients exhibited higher Tregs frequencies and sjTRECs levels than those in the non-MSC group at 8 and 12 weeks after treatment. MSCs derived from bone marrow of a third-party donor are effective to refractory aGVHD. It might reduce the incidence and severity of chronic GVHD in aGVHD patients by improving thymic function and induction of Tregs but not increase the risks of infections and tumor relapse.

Tunable positions of Weyl nodes via magnetism and pressure in the ferromagnetic Weyl semimetal CeAlSi.

The noncentrosymmetric ferromagnetic Weyl semimetal CeAlSi with simultaneous space-inversion and time-reversal symmetry breaking provides a unique platform for exploring novel topological states. Here, by employing multiple experimental techniques, we demonstrate that ferromagnetism and pressure can serve as efficient parameters to tune the positions of Weyl nodes in CeAlSi. At ambient pressure, a magnetism-facilitated anomalous Hall/Nernst effect (AHE/ANE) is uncovered. Angle-resolved photoemission spectroscopy (ARPES) measurements demonstrated that the Weyl nodes with opposite chirality are moving away from each other upon entering the ferromagnetic phase. Under pressure, by tracing the pressure evolution of AHE and band structure, we demonstrate that pressure could also serve as a pivotal knob to tune the positions of Weyl nodes. Moreover, multiple pressure-induced phase transitions are also revealed. These findings indicate that CeAlSi provides a unique and tunable platform for exploring exotic topological physics and electron correlations, as well as catering to potential applications, such as spintronics.

Facile and efficient chitosan-based hygroscopic aerogel for air dehumidification.

Sorption dehumidification, as an energy-saving and eco-friendly approach, has been emerging in application for air dehumidification. Here, a prospective method is proposed to prepare biomass-based hygroscopic aerogels that are easily applicable, sustainable, high-efficient, and recyclable. The chitosan-based aerogel with a porous and hydrophilic network acts as the carrier and water reservoir for the uniformly distributed lithium chloride hygroscopic salt, and provides the hygroscopic salt with more liberal water channels to facilitate moisture capture and transfer. As a consequence, the prepared chitosan/polyvinyl alcohol@lithium chloride (chitosan/PVA@LiCl) hygroscopic aerogel exhibits an excellent moisture absorption capacity of up to 2.77 g g-1 at a relative humidity of 90 %. Meanwhile, as the chitosan/PVA@LiCl aerogel is set in a closed space about 2200 times larger than its own volume, the relative humidity can be reduced from 90 % to 32 % within 2 h, and further lower to 25 % after 4 h. Furthermore, combined with multi-walled carbon nanotubes, the photothermal hygroscopic aerogel is obtained that can rapidly desorb water under sunlight, thus to realize energy-free cycle. Overall, the renewable biomass-based aerogel materials with the advantages of simple preparation and excellent hygroscopic performance provides a new path for the development of sorption dehumidification technology.

Metal-Organic-Framework-Mediated Fast Self-Assembly 3D Interconnected Lignin-Based Cryogels in Deep Eutectic Solvent for Supercapacitor Applications.

A cost-effective and sustainable method is successfully developed to produce lignin-based cryogels with a mechanically robust 3D interconnected structure. A choline chloride-lactic acid (ChCl-LA)-based deep eutectic solvent (DES) is used as a cosolvent to promote the synthesis of lignin-resorcinol-formaldehyde (LRF) gels that can self-assemble a robust string-bead-like framework. The molar ratio of LA to ChCl in DES has a significant influence on the gelation time and properties of the ensuing gels. Moreover, it is discovered that doping the metal-organic framework (MOF) during the sol-gel process can greatly accelerate the gelation of lignin. It takes a mere 4 h to complete the LRF gelation process at a DES ratio of 1:5 combined with 5% MOF. This study yields LRF carbon cryogels doped with copper that exhibit 3D interconnected bead-like carbon spheres with a prominent micropore of 1.2 nm. A specific capacitance as high as 185 F g-1 can be obtained for the LRF carbon electrode at a current density of 0.5 A g-1, and it has an excellent long-term cycling stability. This study provides a novel method of synthesizing high-lignin-content carbon cryogels with promising potential for application in the field of energy storage devices.

Cytokine profiling during conditioning in haploidentical stem cell transplantation and its prognostic impact on early transplant outcomes.

Cytokine storm development is a major cause of many transplant-related complications, especially during the conditioning regimen. This study aimed to characterize the cytokine profile and determine its prognostic impact during conditioning in patients undergoing subsequent haploidentical stem cell transplantation. A total of 43 patients were enrolled in this study. Sixteen cytokines associated with cytokine release syndrome (CRS) during anti-thymocyte globulin (ATG) treatment were quantified in patients undergoing haploidentical stem cell transplantation. Thirty-six (83.7%) patients developed CRS during ATG treatment; most of those cases (33/36; 91.7%) were classified as grade 1 CRS, whereas only three (7.0%) developed grade 2 CRS. CRS was observed more frequently on the first (15/43; 34.9%) and second day (30/43; 69.8%) of ATG infusion. No factors were identified that could predict the development of CRS on the first day of ATG treatment. Five of the 16 cytokines (interleukins 6, 8, and 10 (IL-6, IL-8, and IL-10), C-reactive protein (CRP), and procalcitonin (PCT)) were significantly elevated during ATG treatment, although only the level of IL-6, IL-10, and PCT were associated with the severity of CRS. However, neither CRS nor the cytokine levels significantly impacted the development of acute graft-versus-host disease (GVHD) or cytomegalovirus (CMV) infection or affected overall survival.

Evaluation of pretreatment effect on lignin extraction from wheat straw by deep eutectic solvent.

To investigate the effect of hemicellulose removal on subsequent choline chloride and lactic acid (ChCl-LA) based deep eutectic solvent (DES) extraction of wheat straw lignin, ChCL-LA of DES and hot water presoaking pretreatments were used for hemicellulose prehydrolysis. Both presoakings led to a significant hemicellulose removal and introduced morphological changes on fiber cell wall surface. DES presoaking also instigated ether bonds cleavage between lignin and hemicellulose and selectively removed lignin in compound middle lamella (CML) and cell corner (CC) leading to cell wall disruption and swelling which facilitated lignin extraction. Hot water presoaking removed more hemicellulose and caused a migration of lignin to fibers surface, but did not improve subsequent lignin extraction. This study demonstrated that a two-stage DES treatment method, presoaking at room temperature followed by extracting at an elevated temperature, is a viable process to produce high yield and purity of lignin.

A deep tumor penetration nanoplatform for glycolysis inhibition and antimetastasis of breast cancer.

The poor penetration into deep tumor tissues of nanomedicines could not inhibit the production of lactic acid by deep tumor glycolysis, which leads to the accumulation of lactic acid and promotes tumor metastasis. In order to increase tumor penetration, it remains challenging to avoid tumor metastasis by the direct degradation of the extracellular matrix (ECM). Herein, in order to increase tumor penetration, a nano-platform, which can reduce extracellular matrix (ECM) production, and inhibit the glycolysis of deep tumors by releasing ethylenediaminetetraacetic acid (EDTA) is reported. In this design, EDTA and indocyanine green (ICG) are encapsulated in the liposome by a thin-film hydration method, and folic acid (FA) and the polyethyleneimine polymer (FA-PEI) are applied to coat the surface of liposomes through electrostatic interactions, and the FA-EDTA/ICG-Lip nanoparticles are obtained. FA-EDTA/ICG-Lip NPs can release EDTA and ICG in lysosomes (pH 4.5) to reduce ECM production by down-regulating transforming growth factor ß (TGF-ß) and activating an immune response by inducing tumor cell immunogenic cell death (ICD), respectively. Simultaneously, EDTA inhibits glycolysis of deep tumors by chelating Mg2+. By avoiding tumor metastasis, the strategy of indirectly reducing ECM production is demonstrated to enhance tumor penetration and inhibit deep tumor glycolysis.

Construction of hyperbranched polysiloxane-based multifunctional fluorescent prodrug for preferential cellular uptake and dual-responsive drug release.

Hyperbranched polymers hold great promise in nanomedicine for their controlled chemical structures, sizes, multiple terminal groups and enhanced stability than linear amphiphilic polymer assemblies. However, the rational design of hyperbranched polymer-based nanomedicine with low toxic materials, selective cellular uptake, controlled drug release, as well as real-time drug release tracking remains challenging. In this work, a hyperbranched multifunctional prodrug HBPSi-SS-HCPT is constructed basing on the nonconventional aggregation-induced emission (AIE) featured hyperbranched polysiloxanes (HBPSi). The HBPSi is a biocompatible AIE macromolecule devoid of conjugates, showing a high quantum yield of 17.88% and low cytotoxicity. By covalently grafting the anticancer drug, 10-hydroxycamptothecin (HCPT), to the HBPSi through 3,3'-dithiodipropionic acid, HBPSi-SS-HCPT is obtained. The HBPSis demonstrate obvious AIE features and it turned to aggregation-caused quenching (ACQ) after grafting HCPT owing to the FRET behavior between HBPSi and HCPT in HBPSi-SS-HCPT. In addition to on-demand HCPT release in response to changes in environmental pH and glutathione, a series of in vitro and in vivo studies revealed that HBPSi-SS-HCPT exhibits enhanced accumulation in tumor tissues through the enhanced permeation and retention (EPR) effect and preferential cancer cell uptake by charge reversal, thus resulting in apoptotic cell death subsequently. This newly developed multifunctional HBPSi-SS-HCPT prodrug provides a biocompatible strategy for controlled drug delivery, preferential cancer cell uptake, on-demand drug release and enhanced antitumor efficacy.

A comprehensive model to predict severe acute graft-versus-host disease in acute leukemia patients after haploidentical hematopoietic stem cell transplantation.

BACKGROUND: Acute graft-versus-host disease (aGVHD) remains the major cause of early mortality after haploidentical related donor (HID) hematopoietic stem cell transplantation (HSCT). We aimed to establish a comprehensive model which could predict severe aGVHD after HID HSCT. METHODS: Consecutive 470 acute leukemia patients receiving HID HSCT according to the protocol registered at https://clinicaltrials.gov (NCT03756675) were enrolled, 70% of them (n = 335) were randomly selected as training cohort and the remains 30% (n = 135) were used as validation cohort. RESULTS: The equation was as follows: Probability (grade III-IV aGVHD) = [Formula: see text], where Y = -0.0288 × (age) + 0.7965 × (gender) + 0.8371 × (CD3 + /CD14 + cells ratio in graft) + 0.5829 × (donor/recipient relation) - 0.0089 × (CD8 + cell counts in graft) - 2.9046. The threshold of probability was 0.057392 which helped separate patients into high- and low-risk groups. The 100-day cumulative incidence of grade III-IV aGVHD in the low- and high-risk groups was 4.1% (95% CI 1.9-6.3%) versus 12.8% (95% CI 7.4-18.2%) (P = 0.001), 3.2% (95% CI 1.2-5.1%) versus 10.6% (95% CI 4.7-16.5%) (P = 0.006), and 6.1% (95% CI 1.3-10.9%) versus 19.4% (95% CI 6.3-32.5%) (P = 0.017), respectively, in total, training, and validation cohort. The rates of grade III-IV skin and gut aGVHD in high-risk group were both significantly higher than those of low-risk group. This model could also predict grade II-IV and grade I-IV aGVHD. CONCLUSIONS: We established a model which could predict the development of severe aGVHD in HID HSCT recipients.

Fabrication of Hierarchical Lignin-Based Carbon through Direct High-Temperature Pyrolysis and Its Electrochemical Application.

Green synthesis of lignin-based carbon materials can accelerate the development of energy storage and conversion in supercapacitors. In this work, hierarchical graphenelike carbon was prepared by alkali lignin (AL) pyrolysis at a high temperature of 1700 °C. Accompanied by metal salt catalysis and a nitrogen hybridization reaction, a unique nanostructure of graphitized ALC was obtained with both a well-ordered 2D sheet lamellar structure and a uniform bowl-like porous structure. ALC exhibited a graphenelike lattice structure, a BET specific surface area of 1190 m2·g-1, and excellent electrochemical performance (104 F·g-1/0.5 A·g-1). The study offers a prospective way to the high-value application of industrial lignin in supercapacitor electrode materials.