Prognosis for local radical treatment in patients with esophageal squamous cell carcinoma with low-risk oligometastatic recurrence after curative resection: a retrospective cohort study.

Background: Patients with esophageal carcinoma (EC) with recurrent disease have a poor prognosis. A limited numbers of metastases, safely treatable with curative intent, diagnosed after curative esophagectomy may be defined as oligometastatic recurrence (OLR). However, the appropriate number of metastases and metastatic organs involved remains incompletely characterized. And the role of local therapy in OLR after radical esophagectomy remains unknown. Therefore, this study aimed to more accurately define low-risk OLR in patients with esophageal squamous cell carcinoma (ESCC) treated with radical resection and investigate the role of chemotherapy combined with local treatment (CCLT) in these patients. Methods: A total of 83 sequential patients with ESCC who underwent radical esophagectomy, with an Eastern Cooperative Oncology Group (ECOG) performance status ≤2, with ability to tolerate chemotherapy (CT) and local treatment, and with newly diagnosed recurrence between January 2010 and May 2019 in our hospital were recruited. Overall survival (OS) curves after recurrence were analyzed using the Kaplan-Meier method, and a log-rank test was used to assess the OS differences. Cox proportional hazards regression analysis was performed to identify independent factors associated with 2-year OS. Regular follow-up examinations were assessed by thoracic and upper abdominal computed tomography (CT) scanning every 3 months in the first year, every 6 months over the next 2 years, and yearly thereafter. Results: Of the 83 patients with ESCC (71 males and 12 females), the median age was 56 years (range, 37-79 years). Thirty-five patients with ESCC with ≤5 metastases safely treatable with curative intent located in a single organ had a favorable OS compared to 48 patients with metastases located in 2-3 organs with or without regional recurrence and/or regional lymph node (LN) metastases. In our study, low-risk OLR was defined as the presence of ≤5 metastases safely treatable with curative intent in a single organ and was compared to patients with 2-3 organs involved. The 2-year OS of patients with low-risk OLR with liver oligometastases was significantly worse than survival in patients with lung oligometastases (0% vs. 61.1%, P=0.009). Patients with ESCC in the low-risk OLR group treated with CCLT had a better 2-year OS after recurrence than those who received CT alone (66.7% vs. 30.4%, P=0.003). The multivariable Cox regression model identified treatment method [hazard ratio (HR) 3.920, P=0.02] as an independent factor affecting OS after recurrence for low-risk OLR. Conclusions: Low-risk OLR was defined as ≤5 metastases safely treatable with curative intent in a single organ. Patients with ESCC with low-risk OLR after curative resection treated with CCLT have a favorable OS compared to those treated with CT alone. CCLT is a promising treatment option for patients with ESCC and low-risk OLR.

Molecular Engineering Regulation Achieving Out-of-Plane Polarization in Rare-Earth Hybrid Double Perovskites for Ferroelectrics and Circularly Polarized Luminescence.

Out-of-plane polarization is a highly desired property of two-dimensional (2D) ferroelectrics for application in vertical sandwich-type photoferroelectric devices, especially in ultrathin ferroelectronic devices. Nevertheless, despite great advances that have been made in recent years, out-of-plane polarization remains unrealized in the 2D hybrid double perovskite ferroelectric family. Here, from our previous work 2D hybrid double perovskite HQERN ((S3HQ)4EuRb(NO3)8, S3HQ = S-3-hydroxylquinuclidinium), we designed a molecular strategy of F-substitution on organic component to successfully obtain FQERN ((S3FQ)4EuRb(NO3)8, S3FQ = S-3-fluoroquinuclidinium) showing circularly polarized luminescence (CPL) response. Remarkably, compared to the monopolar axis ferroelectric HQERN, FQERN not only shows multiferroicity with the coexistence of multipolar axis ferroelectricity and ferroelasticity but also realizes out-of-plane ferroelectric polarization and a dramatic enhancement of Curie temperature of 94 K. This is mainly due to the introduction of F-substituted organic cations, which leads to a change in orientation and a reduction in crystal lattice void occupancy. Our study demonstrates that F-substitution is an efficient strategy to realize and optimize ferroelectric functional characteristics, giving more possibility of 2D ferroelectric materials for applications in micro-nano optoelectronic devices.

HT-NMR Studies of the Be-F Coordination Structure in FNaBe and FLiBe Mixed Salts.

Molten NaF-BeF2 salt is widely considered a promising candidate to replace FLiBe in molten salt reactor applications, which is crucial to reducing the operating costs of the molten salt reactor. Studies on beryllium compounds are rarely conducted due to their volatility and high toxicity. Herein, the Be-F coordination structure of NaF/BeF2 mixed salts was investigated in-depth through various HT-NMR and solid-state NMR methods, which are optimized to be appropriate for the detection of beryllium compounds. It was found that Na2BeF4 and NaBeF3 crystals were transformed into amorphous tetrahedral coordinated networks when there was an increase in the BeF2 concentration in the mixed salts. The main coordinate structure comparisons between FNaBe and FLiBe were analyzed, which exhibit high similarity due to the covalent effect of Be-F bonding, demonstrating the theoretical feasibility of applying FNaBe salts as a substitute for FLiBe in MSR systems. In addition, the transition from the crystal phase to the amorphous phase occurred at a lower BeF2 concentration for FNaBe than that for FLiBe. This was further verified by the results of ab initio molecular dynamics (AIMD) simulation that FNaBe melts had more disordered structures, thus causing slight changes in their physical properties.

Rational Design of 2D Metal Halide Perovskites with Low Congruent Melting Temperature and Large Melt-Processable Window.

Metal halide perovskites (MHPs) have garnered significant attention due to their distinctive optical and electronic properties, coupled with excellent processability. However, the thermal characteristics of these materials are often overlooked, which can be harnessed to cater to diverse application scenarios. We showcase the efficacy of lowering the congruent melting temperature (Tm) of layered 2D MHPs by employing a strategy that involves the modification of flexible alkylammonium through N-methylation and I-substitution. Structural-property analysis reveals that the N-methylation and I-substitution play pivotal roles in reducing hydrogen bond interactions between the organic components and inorganic parts, lowering the rotational symmetry number of the cation and restricting the residual motion of the cations. Additional I···I interactions enhance intermolecular interactions and lead to improved molten stability, as evidenced by a higher viscosity. The 2D MHPs discussed in this study exhibit low Tm and wide melt-processable windows, e.g., (DMIPA)2PbI4 showcasing a low Tm of 98 °C and large melt-processable window of 145 °C. The efficacy of the strategy was further validated when applied to bromine-substituted 2D MHPs. Lowering the Tm and enhancing the molten stability of the MHPs hold great promise for various applications, including glass formation, preparation of high-quality films for photodetection, and fabrication of flexible devices.

Atomically precise photothermal nanomachines.

Interfacing molecular machines to inorganic nanoparticles can, in principle, lead to hybrid nanomachines with extended functions. Here we demonstrate a ligand engineering approach to develop atomically precise hybrid nanomachines by interfacing gold nanoclusters with tetraphenylethylene molecular rotors. When gold nanoclusters are irradiated with near-infrared light, the rotation of surface-decorated tetraphenylethylene moieties actively dissipates the absorbed energy to sustain the photothermal nanomachine with an intact structure and steady efficiency. Solid-state nuclear magnetic resonance and femtosecond transient absorption spectroscopy reveal that the photogenerated hot electrons are rapidly cooled down within picoseconds via electron-phonon coupling in the nanomachine. We find that the nanomachine remains structurally and functionally intact in mammalian cells and in vivo. A single dose of near-infrared irradiation can effectively ablate tumours without recurrence in tumour-bearing mice, which shows promise in the development of nanomachine-based theranostics.

SENP5 deteriorates traumatic brain injury via SUMO2-dependent suppression of E2F1 SUMOylation.

Traumatic brain injury (TBI) represents a main public health concern during the past decade, attracting considerable interest because of its rising prevalence, wide-ranging risk factors and lifelong familial and societal influence. SUMO2 can conjugate to substrates upon various cellular stresses. Nevertheless, whether and how SUMO2-specific proteases partake in TBI is less understood. The aim of this study is to dissect the effects of SUMO-specific peptidase 5 (SENP5) on accentuating TBI in rats in an effort to unveil its underlying mechanism. SENP5 is overexpressed in hippocampal tissues of TBI rats, and inhibition of SENP5 reduces neurological function scores, decreases brain water content, inhibits apoptosis in hippocampal tissues, and attenuates brain injury caused in rats. Moreover, SENP5 inhibits the SUMOylation level of E2F transcription factor 1 (E2F1) and increases the protein expression of E2F1. Silencing of E2F1 blocks the p53 signaling pathway. Overexpression of E2F1 partially reverses the protective effect of sh-SENP5 on TBI in rats. These findings reveal an essential role of SENP5 and the SUMOylation status of E2F1 in the TBI development.

Probing the local structure of FLiBe melts and solidified salts by in situ high-temperature NMR.

The 2LiF-BeF2 (FLiBe) salt melt is considered the primary choice for a coolant and fuel carrier for the generation IV molten salt reactor (MSR). However, the basics of ionic coordination and short-range ordered structures have been rarely reported due to the toxicity and volatility of beryllium fluorides, as well as the lack of suitable high-temperature in situ probe methods. In this work, the local structure of FLiBe melts was investigated in detail using the newly designed HT-NMR method. It was found that the local structure was comprised of a series of tetrahedral coordinated ionic clusters (e.g., BeF42-, Be2F73-, Be3F104-, and polymeric intermediate-range units). Li+ ions were coordinated by BeF42- ions and the polymeric Be-F network through the analysis of the NMR chemical shifts. Using solid-state NMR, the structure of solid FLiBe solidified mixed salts was confirmed to form a 3D network structure, significantly similar to those of silicates. The above results provide new insights into the local structure of FLiBe salts, which verifies the strong covalent interactions of Be-F coordination and the specific structural transformation to the polymeric ions above 25% BeF2 concentration.

Probing distribution and dynamics of lithium ions in supermolecule ß-CD-PEO/Li+ solid polymer electrolytes via solid-state NMR.

In this work, the distribution and dynamics of Li+ ions in ß-CD-PEO/Li+ (ß-CD, ß-cyclodextrin; PEO, polyethylene-oxides) crystalline polymer electrolytes were investigated by solid-state NMR to enlighten the ionic conduction mechanism. Specifically, 7Li-6Li REDOR NMR and variable-contact-time 1H-6Li CP/MAS NMR were adopted for the study. The results demonstrate that Li+ ions coordinated by polymer chains have relatively compact spatial density and fast dynamics, which facilitate the improvement of the electrochemical properties. Additionally, the variation of the distribution and dynamics of the Li+ ions and the ionic conduction mechanism were studied and discussed by altering the amount of the Li+ ions. This work deepens our understanding of the distribution and dynamics of Li+ ions in ß-CD-PEO/Li+ crystals and demonstrates possible future applications of solid-state NMR on the study of the polymer electrolytes.

Do all patients at the initial stage of nasopharyngeal carcinoma need bone metastasis screening? A retrospective study.

BACKGROUND: To identify patients at low risk of synchronous bone metastasis who should not receive bone scans when initially diagnosed with nasopharyngeal carcinoma (NPC). METHODS: In total, 6652 patients were enrolled in the training cohort and 1919 patients in the multicenter external validation cohort. Logistic regression analyses were performed to assess independent predictors of synchronous bone metastasis for the nomogram model. RESULTS: After risk stratification, 46.3% (3081/6652) patients were separated into the low-risk group with an incidence of 0.71% for synchronous bone metastasis. The odds ratio of the intermediate and high-risk groups was 5.61 and 23.82 times that of the low-risk group, respectively. For patients with high EBV DNA, we recommend routine screening for N2-3 female patients, but that all male subgroups are screened. CONCLUSIONS: Bone scans should not be routine. Patients in the low-risk group should not be screened, which would avoid excessive radiation and economize iatrical resource.

Study on the defect reduction of metal folding on the formed tooth top with finishing roller in gear rolling process.

Cross rolling process is a new method to manufacture large-diameter gears, which has great advantages. While during the gear manufacturing process with cross rolling, due to the difference of deformation mechanism between the right and left formed tooth profiles, a tip is pulled at the tooth top of the workpiece, which severely affects the forming quality. To eliminate the occurred defect, the finishing roller is proposed and designed, the motion equation of the finishing roller is established and solved, the principle of the height increase of the formed tooth is obtained. And also a simplified finite element (FE) model with finishing roller and non-finishing roller are established in the DEFORM-3D software. The comparison of the simulation results between two situations is analyzed and can be concluded that with the finishing roller, the protrusions at both sides of the tooth top of the workpiece at each stage are flattened by the finishing roller, and the accumulation of the tooth top protrusions is not going to occur, which means no extrusion and finishing of the tooth top of the workpiece are required. In addition, the experiment with the finishing roller is carried out and the effectiveness of the finishing roller can be verified.

The Effect of Ophiopogonin C in Ameliorating Radiation-Induced Pulmonary Fibrosis in C57BL/6 Mice: An Update Study.

Background: The aim of this study was to assess and update the protective effects and underlying mechanisms of Ophiopogonin C (OP-C), a biologically active component separated and purified from Ophiopogon japonicus, in ameliorating radiation-induced pulmonary fibrosis in C57BL/6 mice administered thoracic radiation. Methods and Materials: We randomly divided 75 mice into five groups and administered a dose of 12-Gy whole thoracic radiation to establish a pulmonary fibrosis animal model. Mice were treated with OP-C or dexamethasone combined with or without cephalexin by daily gavage for 4 weeks. All mice were sacrificed after the completion of thoracic irradiation at 28 weeks. Serum levels of interleukin-6 and transforming growth factor-ß1 (TGF-ß1) were evaluated. Moreover, superoxide dismutase (SOD) levels in lung tissue were measured. The severity of fibrosis was evaluated using the hydroxyproline content of the lung tissue. The pathological changes in the five groups were detected by hematoxylin and eosin and Masson trichrome staining. Smooth muscle actin expression was detected using immunohistochemical staining. Matrix metalloproteinases-2 (MMP-2) and tissue inhibitors of metalloproteases-2 (TIMP-2) were examined by immunohistochemical staining of the lung sections, and semiquantitative analysis was used to calculate the expression of MMP-2 and TIMP-2. Results: Irradiated mice treated with OP-C or DXE combined with or without cephalexin significantly reduced mortality in mice and fibrosis levels by 1) reducing the deposition of collagen and accumulation of inflammatory cells and fibroblasts, 2) downgrading levels of the promote-fibrosis cytokine TGF-ß1, and 3) increasing SOD activity in the lung tissue compared with that of irradiated mice without treatment. However, there were no statistical differences in fibrosis levels among the irradiated mice treated with OP-C or DXE combined with or without cephalexin. Conclusion: OP-C significantly ameliorates radiation-induced pulmonary fibrosis and may be a promising therapeutic strategy for this disorder.

Highly Flexibility, Powder Self-Healing, and Recyclable Natural Polymer Hydrogels.

Based on the good self-healing ability to repair mechanical damage, self-healing hydrogels have aroused great interest and been extensively applied as functional materials. However, when partial failure of hydrogels caused by breaking or dryness occurs, leading to recycling problems, self-healing hydrogels cannot solve the mentioned defects and have to be abandoned. In this work, a novel recyclable and self-healing natural polymer hydrogel (Chitosan/polymethylacrylic acid-: CMA) was prepared. The CMA hydrogel not only exhibited controlled mechanical properties from 26 kPa to 125 kPa with tensile strain from 1357% to 3012%, but also had good water retaining property, stability and fast self-healing properties in 1 min. More importantly, the CMA hydrogel displayed attractive powder self-healing performance. After drying-powdering treatment, the mentioned abandoned hydrogels could easily rebuild their frame structure to recover their original state and performance in 1 min only by adding a small amount of water, which could significantly prolong their service life. These advantages guarantee the hydrogel can effectively defend against reversible mechanical damage, water loss and partial hydrogel failure, suggesting great potential applications as a recyclable functional hydrogel for biomaterials and electronic materials.

Polyarylether-Based 2D Covalent-Organic Frameworks with In-Plane D-A Structures and Tunable Energy Levels for Energy Storage.

The robust fully conjugated covalent organic frameworks (COFs) are emerging as a novel type of semi-conductive COFs for optoelectronic and energy devices due to their controllable architectures and easily tunable the highest occupied molecular orbital (HOMO) and the lowest occupied molecular orbital (LUMO) levels. However, the carrier mobility of such materials is still beyond requirements due to limited π-conjugation. In this study, a series of new polyarylether-based COFs are rationally synthesized via a direct reaction between hexadecafluorophthalocyanine (electron acceptor) and octahydroxyphthalocyanine (electron donor). These COFs have typical crystalline layered structures, narrow band gaps as low as ≈0.65 eV and ultra-low resistance (1.31 × 10-6 S cm-1 ). Such COFs can be composed of two different metal-sites and contribute improved carrier mobility via layer-altered staking mode according to density functional theory calculation. Due to the narrow pore size of 1.4 nm and promising conductivity, such COFs and electrochemically exfoliated graphene based free-standing films are fabricated for in-plane micro-supercapacitors, which demonstrate excellent volumetric capacitances (28.1 F cm-3 ) and excellent stability of 10 000 charge-discharge cycling in acidic electrolyte. This study provides a new approach toward dioxin-linked COFs with donor-acceptor structure and easily tunable energy levels for versatile energy storage and optoelectronic devices.

A-Site Mixing to Adjust the Photovoltaic Performance of a Double-Cation Perovskite: It Is Not Always the Simple Way.

Considerable progress has been made in improving the performance of optoelectronic devices based on hybrid organic-inorganic perovskites of the form ABX3. However, the influences of A-site doping on the structure and dynamics of the inorganic perovskite crystal lattice and, in turn, on the optoelectronic performance of the resulting devices remain poorly understood at an atomic level. This work addresses this issue by combining the results of several experimental characterization methods for three-dimensional MA1-xDMAxPbBr3 perovskite single crystals (MA, methylammonium; DMA, dimethylammonium). The results reveal a two-stage change in lattice with an increase in DMA content, which has completely opposite effects on the optoelectronic performance of the double-cation perovskite. At low DMA concentrations, fast reorientation of incorporated DMA cations strengthens the interaction between MA cations and the lattice without significant lattice distortion, which could suppress lattice fluctuation and thus improve the photovoltaic performance. At high DMA concentrations, the lattice get a severe distortion, leading to poorer photovoltaic performance.

NMR study on the cellulose dissolution mechanism in CaCl2·6H2O-LiCl molten salt hydrate.

As there is a rising interest in upgrading cellulose to high-performance bio-products, the studies on innovative reaction media and processes have been leaping forward. Green solvents in terms of cellulose dissolution and brief processes for upgrading are critical to green chemistry. However, most solvent systems generally exhibit defects in harsh pH operating windows with limited temperature ranges, environmental pollution, long reaction times, complicated processes, etc. In this work, we have provided a novel molten salt hydrate (CaCl2·6H2O-LiCl) as a green solvent and investigated the role of hydrated molten salts in the dissolution process via the solid state nuclear magnetic resonance (NMR) technique. The cellulose could be dissolved in CaCl2·6H2O-LiCl molten salt hydrated at 120 °C with 3.0% solubility and regenerated in-situ by cooling down to ambient temperature. The regenerated cellulose exhibited a high solubility and excellent stability. From 7Li single pulse NMR experiments, it was observed that two types of Li+ existed in the cellulose dissolution, and the Li+ significantly impacted the dissolving process and the dissolution ability of cellulose. This work would provide an environmental-friendly strategy to prepare cellulose solutions for biocompatible cellulose materials.

Deuterated Covalent Organic Frameworks with Significantly Enhanced Luminescence.

Luminescent covalent organic frameworks (COFs) find promising applications in chemical sensing, photocatalysis, and optoelectronic devices, however, the majority of COFs are non or weakly emissive owing to the aggregation-caused quenching (ACQ) or the molecular thermal motion-based energy dissipation. Here, we report a previously unperceived approach to improve luminescence performance of COFs by introducing isotope effect, which is achieved through substitution of hydrogen from high-frequency oscillators X-H (X=O, N, C) by heavier isotope deuterium. Combining the "bottom-up" and in situ deuteration methods generates the first deuterated COF, which exhibits an impressively 19-fold enhancement in quantum yield over that of the non-deuterated counterpart. These results are interpreted by theoretical calculations as the consequence of slower C/N-D and OD⋅⋅⋅O vibrations that impede the nonradiative deactivation process. The proposed strategy is proved applicable to many other types of emissive COFs.

Quinone-Enriched Conjugated Microporous Polymer as an Organic Cathode for Li-Ion Batteries.

Among various organic cathode materials, C═O group-enriched structures have attracted wide attention worldwide. However, small organic molecules have long suffered from dissolving in electrolytes during charge-discharge cycles. π-Conjugated microporous polymers (CMPs) become one solution to address this issue. However, the synthesis strategy for CMPs with rich C═O groups and stable backbones remains a challenge. In this study, a novel CMP enriched with C═O units was synthesized through a highly efficient Diels-Alder reaction. The as-prepared CMP exhibited a fused carbon backbone and a semiconductive characteristic with a band gap of 1.4 eV. When used as an organic electrode material in LIBs, the insoluble and robust fused structure caused such CMPs to exhibit remarkable cycling stability (a 96.1% capacity retention at 0.2 A g-1 after 200 cycles and a 94.8% capacity retention at 1 A g-1 after 1500 cycles), superior lithium-ion diffusion coefficient (5.30 × 10-11 cm2 s-1), and excellent rate capability (95.8 mAh g-1 at 1 A g-1). This study provided a novel synthetic method for fabricating quinone-enriched fused CMPs, which can be used as LIB cathode materials.

A Powder Self-Healable Hydrogel Electrolyte for Flexible Hybrid Supercapacitors with High Energy Density and Sustainability.

Ionic conductive hydrogel electrolyte is considered to be an ideal electrolyte candidate for flexible supercapacitor due to its flexibility and high conductivity. However, due to the lack of effective recycling methods, a large number of ineffective flexible hydrogel supercapacitors caused by some irreversible damages and dryness of hydrogel electrolyte are abandoned, which would induce heavy economic and environmental protection problems. Herein,a smart ionic conductive hydrogel (SPMA-Zn: ZnSO4 /sodium alginate/polymethylacrylic acid) is developed for flexible hybrid supercapacitor (SPMA-ZHS). The SPMA-Zn exhibits an excellent self-healing ability and can recover its electrochemical performance after multiple mechanical damages. More importantly, it possesses an outstanding powder self-healable property, which could easily regenerate the hydrogel electrolyte after powdering, and maintain stable electrochemical performance of SPMA-ZHS. Besides, the SPMA-ZHS displays excellent electrochemical performance with a wide and stable working voltage range of 0-2.2 V, high energy density of 164.13 Wh kg-1 at the power density of 1283.44 Wh kg-1 and good stability with a capacity retention of 95.3% after 5000 charge/discharge cycles at 10 A g-1 . The strategy in this work would provide a new insight in exploring flexible hydrogel electrolyte-based supercapacitor with good sustainability and high energy density for flexible wearable electronic devices.

Probing the ionic structure of FLiNaK-ZrF4 salt mixtures by solid-state NMR.

In this study, by applying 19F, 23Na and 7Li high-resolution NMR methods, the evolution of the [Zr x F y ]4x-y local ionic structures in FLiNaK-ZrF4 salt mixtures were elucidated. K3ZrF7, Na3ZrF7 and Na7Zr6F31 crystal phases were identified when the melt salts were being solidified. The distribution of these [Zr x F y ]4x-y species was dependent on the content of ZrF4 in FLiNaK eutectic salts. Moreover, K3ZrF7 phase transition from an orthorhombic lattice into a disordered cubic lattice was clarified, thereby causing dynamics of the coordinated F- ions to be reduced and the well-ordered crystal lattices to be destroyed. These mentioned results provide a further insight into the Zr-F based ionic structure and the formation of the disordered Zr-F structure in ZrF4-based eutectic salts.