Advanced "turn-on" colorimetric uranium platform based on the enhanced nanozyme activity of a donor-acceptor structured covalent organic framework.

BACKGROUND: The increasing uranium containing wastes generated during uranium mining and finishing pose a huge threat to the environment and human health, and thus robust strategies for on-site monitoring of uranium pollutant are of great significance for environmental protection around uranium tailings. RESULTS: Herein, a facile "turn-on" colorimetric platform that can achieve uranium detection by spectrometry and naked eyes was developed based on the uranium-enhanced nanozyme activity of covalent organic framework (JUC-505). Thanks to the extended π-conjugated skeleton and donor-acceptor (D-A) structure, JUC-505 exhibited superior photo-activated nanozyme activity, which would be prohibited when the cyano group in JUC-505 skeleton was transformed to the amidoxime group. Further results elucidated that the coordination of uranium with amidoxime groups led to the electron transfer between uranium and the JUC-505-AO skeleton, and thus significantly restored the nanozymatic activity of JUC-505-AO with the subsequent remarkable color changes. Moreover, the uranium concentrations in uranium tailing wastewater detected by the present "turn-on" colorimetric method were well agreed with those by ICP-MS, demonstrating a high accuracy of the present method in real samples. SIGNIFICANCE: The D-A structured JUC-505 with superior photocatalytic property and nanozymatic activity was applied to facilitate colorimetric detection of uranium, which displays the advantages of low detection limit, excellent selectivity, fast response and simple operation for uranium detection in real samples, and shows a great potential in on-site monitoring of uranium pollutant around uranium tailings as well as nuclear power plant.

Cobalt-Promoted Photoredox 1,2-Amidoamination of Alkenes with N-Sulfonamidopyridin-1-ium Salts and Free Amines.

A cobalt-promoted photoredox 1,2-amidoamination of alkenes with N-sulfonamidopyridin-1-ium salts and free amines for the synthesis of unsymmetrical vicinal diamines has been developed. The reaction handles N-(sulfonamido)pyridin-1-ium salts as the sulfonamidyl radical precursors and free amines as the nucleophilic terminating reagents to enable the formation of two new C(sp3)-N bonds in a single reaction step and offers a route to selectively producing unsymmetrical vicinal diamines with an exquisite selectivity and a good compatibility of functional groups.

[Establishment of a Rat Model of Hypotension Induced by Reserpine].

Objective To determine the optimal dosage and intervention duration of reserpine to establish a rat model of hypotension.Methods According to the body weight and systolic blood pressure (SBP),60 male Wistar rats were assigned to six groups (n=10),including a control group and five observation groups with different doses.The control group was administrated with 10 ml/kg 0.5% sodium carboxymethyl cellulose solution,and the observation groups with 0.016,0.032,0.064,0.128,and 0.160 mg/kg reserpine suspensions,respectively.All the groups were administrated by gavage twice a day,and the body weights of rats were monitored daily.SBP and heart rate (HR) were measured before modeling and 1-6 weeks after administration.After 6 weeks of administration,the blood samples of inner canthus were collected.The levels of lactate dehydrogenase (LDH),creatine kinase MB isoenzyme (CK-MB),alanine aminotransferase,aspartate aminotransferase (AST),serum creatinine,and blood urea nitrogen (BUN) were measured by an autoanalyzer.Three rats in each group were randomly selected for observation of the changes in SBP after drug withdrawal and the rest rats were sacrificed for measurement of the levels of norepinephrine and dopamine in the brain.Results Compared with the control group,different doses of reserpine lowered the SBP of rats (F=28.492,P<0.001).The decline in SBP increased in a concentration-dependent manner.SBP reached the lowest value after 1 week,rose slightly later,and was stable after 3 weeks of administration.There was no significant difference in SBP between 0.016 mg/kg reserpine group and the control group after the 5th week (P>0.05).The SBP levels of rats in 0.032,0.064,0.128,and 0.160 mg/kg reserpine groups showed no significant difference between each other (P=0.204) and were lower than that in the control group (all P<0.001).One week after drug withdrawal,the SBP of rats in the observation groups rose to the baseline level and remained stable.HR showed similar changes among groups,first increasing and then decreasing.There was no significant difference in HR among different groups at the same time point (F=0.922,P=0.475).Compared with the control group,reserpine of different doses reduced the norepinephrine content in the hippocampus (all P<0.001),and 0.128 mg/kg (P=0.045) and 0.160 mg/kg (P=0.042) reserpine lowered the dopamine level in the striatum,which showed no significant differences between different reserpine groups(P=0.343,P=0.301).The levels of LDH,CK-MB,and BUN in the serum increased with the increase in reserpine concentration,and the levels of LDH (P=0.001),CK-MB (P=0.020),AST (P=0.007),and BUN (P=0.001) in the 0.160 mg/kg reserpine group were significantly different from those in the control group.Conclusions The rat model of hypotension can be induced by gavage with reserpine.The gavage with reserpine at a dose of 0.032 mg/kg,twice a day for three consecutive weeks is the optimal scheme for the modeling.After the model establishment,continuous administration is essential to maintain the hypotension.

Band engineering enhances the electrochemical properties by constructing TiO2 NRs-MoS2 NSFs flexible electrode.

Research and development of flexible electrodes with high performance are crucial to largely determine the performance of flexible lithium-ion batteries (FLIBs) to a large extent. In this work, a flexible anode (TiO2 NRs-MoS2 NSFs/CC) is rationally designed and successfully constructed, in which TiO2 nanorods arrays (NRs) vertically grown on CC as a supporting backbone for MoS2 nanosheets flowers (NSFs) to form a TiO2 NRs-MoS2 NSFs heterostructure. The backbone can not only serve as a mechanical support MoS2 and improve its electronic conductivity, but also limit the dissolution of polysulfides issue during cycling. The density functional theory (DFT) analysis manifests that the obvious interaction between O and S at the interface for the TiO2 NRs-MoS2 NSFs heterostructure changes the electronic structure and reduces the band gap of TiO2 NRs-MoS2 NSFs. The small band gap and high electron state at the Fermi level are both beneficial to the transport of electrons, enhancing the kinetics, and giving the long cycling stability at high density and excellent rate capacity. Furthermore, the assembled TiO2 NRs-MoS2 NSFs/CC//NCM622 full cell delivers superior rate capacity and good cycling stability. Meanwhile, the soft-packed cell shows good mechanical flexibility, which can be lighted up successfully and keep brightness when folding with different angles. This result illustrates that it is a highly potential strategy for constructing flexible electrodes with the controlled electronic structure through band engineering to not only improve the electrochemical performance, but also possibly meet the requirements of high-performance FLIBs.

Zinc Single-Atom-Regulated Hard Carbons for High-Rate and Low-Temperature Sodium-Ion Batteries.

Hard carbons, as one of the most commercializable anode materials for sodium-ion batteries (SIBs), have to deal with the trade-off between the rate capability and specific capacity or initial Columbic efficiency (ICE), and the fast performance decline at low temperature (LT) remains poorly understood. Here, a comprehensive regulation on the interfacial/bulk electrochemistry of hard carbons through atomic Zn doping is reported, which demonstrates a record-high reversible capacity (546 mAh g-1 ), decent ICE (84%), remarkable rate capability (140 mAh g-1 @ 50 A g-1 ), and excellent LT capacity (443 mAh g-1 @ -40 °C), outperforming the state-of-the-art literature. This work reveals that the Zn doping can generally induce a local electric field to enable fast bulk Na+ transportation, and meanwhile catalyze the decomposition of NaPF6 to form a robust inorganic-rich solid-electrolyte interphase, which elaborates the underlying origin of the boosted electrochemical performance. Importantly, distinguished from room temperature, the intrinsic Na+ migration/desolvation ability of the electrolyte is disclosed to be the crucial rate-determining factors for the SIB performance at LT. This work provides a fundamental understanding on the charge-storage kinetics at varied temperatures.

Simultaneous detection and separation of uranium based on a fluorescent amidoxime-functionalized covalent organic polymer.

To ensure the long-term sustainable development of nuclear energy as well as the prevention and control of uranium pollution, new materials that can simultaneously detect and separate uranium are still urgently needed. Herein, a new fluorescent covalent organic polymer (COP), namely HT-COP-AO, was synthesized andemployed as both the fluorescent probe and absorbent for simultaneous uranium detection and separationconsidering its excellent fluorescence property and strong uranium coordination ability. The results showed that the fluorescence of HT-COP-AO was quickly quenched by uranium within 2 min, and the limit of detection was 0.23 µM (3σ/K). Further studies implied that uranium was coordinated with the amidoxime groups of HT-COP-AO through U-N and O = U = O bonds, which resulted in electron transfer from uranium to HT-COP-AO and quenching the fluorescence of HT-COP-AO consequently. Meanwhile, HT-COP-AO exhibited excellent absorption ability towards uranium, and the maximum absorption capacity (qmax = 401.3 mg/g) was higher than most reported amidoxime modified materials. The HT-COP-AO also showed high selectivity for both uranium detection and separation which makes it a great promising for uranium monitoring in real water samples.

Health risk and spatial distribution characteristics of heavy metal exposure in typical abandoned mining area in Liuzhou, Guangxi / 环境与职业医学

Background Exposure to heavy metals has potential adverse impacts on human health, and the concentration of heavy metals in abandoned mining areas may still be higher than that in general areas, so the health risk assessment in such areas cannot be ignored. Objective To explore the health risk of heavy metal exposure and the spatial distribution characteristics of associated main metals in a typical abandoned mining area. Methods Environmental samples of irrigated soil, rice, and drinking water were collected from 13 natural villages under the jurisdiction of a township in Liuzhou, Guangxi from November to December 2019, where a typical abandoned mining was located. Finally, 13 irrigation soil samples, 11 rice samples, and 13 drinking water samples were collected. The concentrations of six metals and metalloid elements in each environmental sample were detected by inductively coupled-plasma mass spectrometry (ICP-MS), including cadmium (Cd), arsenic (As), lead (Pb), chromium (Cr), copper (Cu), and zinc (Zn). At the same time, 251 local residents were recruited for health risk assessment. Model parameters such as body weight, rice intake, and drinking water intake of local residents were obtained through field survey, and the median metal concentration of each environmental sample was taken as the risk assessment parameter of the region. The health risk of heavy metal exposure of local residents was assessed by using oral health risk assessment model of U.S. Environmental Protection Agency. The spatial distribution characteristics of health risks associated with heavy metals were evaluated by empirical Bayes interpolation method using Geographic Information System (GIS) technology. Results The positive rates of Cd, As, Pb, Cr, Cu, and Zn in the irrigated soil samples were 100.00%. The positive rate of Pb was 63.64% in the rice samples, while the rates of other metals were 100.00%. The positive rates of Cd, As, Pb, Cr, Cu, and Zn in the drinking water samples were 53.85%, 76.92%, 92.31%, 15.38%, 84.62%, and 100.00%, respectively. The results of non-carcinogenic risk assessment of oral exposure to heavy metals suggested that the contribution of heavy metals causing non-carcinogenic risk from high to low was As (70.52%) > Cd (18.03%) > Zn (6.63%) > Cu (4.12%) > Pb (0.64%) > Cr (0.06%), and the corresponding estimated non-carcinogenic risk values were 3.54 × 100, 9.05 × 10−1, 3.33 × 10−1, 2.07 × 10−1, 3.23 × 10−2, and 5.42 × 10−4, respectively. The results of carcinogenic risk assessment of oral exposure to heavy metals suggested that the contribution of studied metals from high to low was Cd (87.00%) > As (10.24%) > Cr (2.60%) > Pb (0.16%), and the estimated carcinogenic risks were 4.35× 10−3, 5.12 × 10−4, 1.30 × 10−4, and 3.08 × 10−7, respectively. Rice was the leading media associated with non-carcinogenic risk and carcinogenic risk (99.4% and 99.8% respectively). The spatial distribution characteristics of GIS showed no obvious regularity in the distribution of As in irrigated soil, rice, and drinking water. In rice and irrigated soil, the content of Cd in the villages adjacent to the mining area was obviously higher than that in the other villages, while in drinking water, the content in the villages far away from the mining area was higher. Conclusion As and Cd are the main heavy metals that increase the health risk of local residents in a typical abandoned mining area, and the distribution characteristics of the two heavy metals in different environmental media are not completely consistent.

Establishment of a Rat Model of Hypotension Induced by Reserpine / 中国医学科学院学报

Objective To determine the optimal dosage and intervention duration of reserpine to establish a rat model of hypotension.Methods According to the body weight and systolic blood pressure (SBP),60 male Wistar rats were assigned to six groups (n=10),including a control group and five observation groups with different doses.The control group was administrated with 10 ml/kg 0.5% sodium carboxymethyl cellulose solution,and the observation groups with 0.016,0.032,0.064,0.128,and 0.160 mg/kg reserpine suspensions,respectively.All the groups were administrated by gavage twice a day,and the body weights of rats were monitored daily.SBP and heart rate (HR) were measured before modeling and 1-6 weeks after administration.After 6 weeks of administration,the blood samples of inner canthus were collected.The levels of lactate dehydrogenase (LDH),creatine kinase MB isoenzyme (CK-MB),alanine aminotransferase,aspartate aminotransferase (AST),serum creatinine,and blood urea nitrogen (BUN) were measured by an autoanalyzer.Three rats in each group were randomly selected for observation of the changes in SBP after drug withdrawal and the rest rats were sacrificed for measurement of the levels of norepinephrine and dopamine in the brain.Results Compared with the control group,different doses of reserpine lowered the SBP of rats (F=28.492,P<0.001).The decline in SBP increased in a concentration-dependent manner.SBP reached the lowest value after 1 week,rose slightly later,and was stable after 3 weeks of administration.There was no significant difference in SBP between 0.016 mg/kg reserpine group and the control group after the 5th week (P>0.05).The SBP levels of rats in 0.032,0.064,0.128,and 0.160 mg/kg reserpine groups showed no significant difference between each other (P=0.204) and were lower than that in the control group (all P<0.001).One week after drug withdrawal,the SBP of rats in the observation groups rose to the baseline level and remained stable.HR showed similar changes among groups,first increasing and then decreasing.There was no significant difference in HR among different groups at the same time point (F=0.922,P=0.475).Compared with the control group,reserpine of different doses reduced the norepinephrine content in the hippocampus (all P<0.001),and 0.128 mg/kg (P=0.045) and 0.160 mg/kg (P=0.042) reserpine lowered the dopamine level in the striatum,which showed no significant differences between different reserpine groups(P=0.343,P=0.301).The levels of LDH,CK-MB,and BUN in the serum increased with the increase in reserpine concentration,and the levels of LDH (P=0.001),CK-MB (P=0.020),AST (P=0.007),and BUN (P=0.001) in the 0.160 mg/kg reserpine group were significantly different from those in the control group.Conclusions The rat model of hypotension can be induced by gavage with reserpine.The gavage with reserpine at a dose of 0.032 mg/kg,twice a day for three consecutive weeks is the optimal scheme for the modeling.After the model establishment,continuous administration is essential to maintain the hypotension.

Electronic synergy to boost the performance of NiCoP-NWs@FeCoP-NSs anodes for flexible lithium-ion batteries.

Research and development of flexible lithium-ion batteries (LIBs) with high energy density and long cycle life for portable and wearable electronic devices has been a cutting-edge effort in recent years. In this paper, a novel flexible self-standing anode for LIBs is fabricated successfully, in which NiCoP nanowires (NWs) coated with FeCoP nanosheets (NSs) to form core-shell heterostructure arrays are grown on carbon cloth (CC) (designated as NiCoP-NWs@FeCoP-NSs/CC). The obtained NiCoP-NWs@FeCoP-NSs/CC anode integrates the merits of the one-dimensional (1D) NiCoP-NW core and two-dimensional (2D) FeCoP-NS shell and the CC to show a high lithium-ion storage capacity with long-term cycling stability (1172.6 mA h g-1 at 1 A g-1 up to 300 cycles with a capacity retention of 92.6%). The kinetics studies demonstrate that the pseudocapacitive behavior dominates the fast lithium storage of this anode material. For fundamental mechanistic understanding, density functional theory (DFT) analysis is carried out, and manifests that electronic synergy can boost the superior performance of the NiCoP-NWs@FeCoP-NSs/CC anode. The assembled LiFePO4//NiCoP-NWs@FeCoP-NSs/CC full battery gives a discharge capacity of 469.9 mA h g-1 at 0.5 A g-1 after 500 cycles, and even at 2 A g-1, it still can retain 581.5 mA h g-1. Besides, the soft pack full battery can keep the LED lit continuously when it is folded at different angles and maintain brightness for a period of time, highlighting the large application potential of this flexible LIB for wearable electronic devices. This work provides an idea for the design and construction of advanced metal phosphide flexible electrodes for LIBs.

Plant-Derived Molecule 4-Methylumbelliferone Suppresses FcεRI-Mediated Mast Cell Activation and Allergic Inflammation.

Mast cells (MCs) are an important treatment target for high-affinity IgE Fc receptor (FcεRI)-mediated allergic diseases. The plant-derived molecule 4-methylumbelliferone (4-MU) has beneficial effects in animal models of inflammation and autoimmunity diseases. The aim of this study was to examine 4-MU effects on MC activation and probe the underlying molecular mechanism(s). We sensitized rat basophilic leukemia cells (RBLs) and mouse bone marrow-derived mast cells (BMMCs) with anti-dinitrophenol (DNP) immunoglobulin (Ig)E antibodies, stimulated them with exposure to DNP-human serum albumin (HSA), and then treated stimulated cells with 4-MU. Signaling-protein expression was determined by immunoblotting. In vivo allergic responses were examined in IgE-mediated passive cutaneous anaphylaxis (PCA) and ovalbumin (OVA)-induced active systemic anaphylaxis (ASA) mouse models. 4-MU inhibited ß-hexosaminidase activity and histamine release dose-dependently in FcεRI-activated RBLs and BMMCs. Additionally, 4-MU reduced cytomorphological elongation and F-actin reorganization while down-regulating IgE/Ag-induced phosphorylation of SYK, NF-κB p65, ERK1/2, p38, and JNK. Moreover, 4-MU attenuated the PCA allergic reaction (i.e., less ear thickening and dye extravasation). Similarly, we found that 4-MU decreased body temperature, serum histamine, and IL4 secretion in OVA-challenged ASA model mice. In conclusion, 4-MU had a suppressing effect on MC activation both in vitro and in vivo and thus may represent a new strategy for treating IgE-mediated allergic conditions.

[Study on the application of a new type of vertebral plate nail guide].

OBJECTIVE: To explore safety and accuracy of novel C2 laminar staple guide through in vitro experiments. METHODS: From January 2018 to June 2018, 40 patients who underwent three-dimensional CT of cervical spine were selected, including 21 males and 19 females, heighted from 165 to 180 cm with an average of (172.9±9.5) cm, aged from 38 to 55 years old (51.1±12.8) years old, excluding patients with axis lamina defect and hypoplasia. Two sets of 3D printed specimens were made from the three-dimensional CT data of cervical spine of each patient, and both of than were used for the in vitro nailing experiment. According to different nail placement methods, in vitro experimental part of this experiment was divided into guide nail placement group and hand nail placement group, 40 pieces in each group. At the same time, the three-dimensionalmodel of cervical spine of 40 patients was reconstructed on computer, and the ideal needle point data and inclination angle were obtained by computer simulation of the nail placement. This is 3D simulation nail placement group, 40 pieces. With vitro experiment, the risk level of screw placement, the position of needle exit point and inclination angle were measured in guide nail group and hand nail group. Based on the accuracy of needle point and inclination angle of nail path, the data of guide nail group, the hand nail group and 3D simulation nail group were compared, and the data of each group were statistically analyzed to determine the accuracy. RESULTS: In guide nail group, 75 screws were acceptable and 5 were dangerous. The acceptable rate was 94%, and the double cortical rate was 93%. There were 62 position-acceptable screws in hand nail group, and 18 positions were dangerous, with an acceptable rate of 78% and a double cortical rate of 33%. The difference between two groups was statistically significant (P<0.05). There was no significant difference in accuracy of needle exit point and inclination angle of nail path between guide nail group and 3D simulation nail group (P>0.05), but there was significant difference in the accuracy of needle exit point and inclination angle of nail path between hand nail group and 3D simulation nail group (P<0.05). CONCLUSION: The guide is universal, with stable structure, accurate guidance, and easy operation. It could be placed with bilateral lamina screws at the same time, shortening the time of nail placement, avoiding collision of two way cross screws, increase the rate of double cortex. Ultimately, efficiency and security can be improved.

Dual Palladium/Copper-Catalyzed anti-Selective Intermolecular Allenylsilylation of Terminal Alkynes: Entry to (E)-Silyl Enallenes.

A palladium-/copper-cocatalyzed three-component trans-allenylsilylation of terminal alkynes with propargyl acetates and PhMe2SiBpin is described, which is driven by the regioselective allenylation of the alkyne with propargyl acetates and then silylation. This method allows the simultaneous incorporation of an allene and silicon across the C≡C bond and provides a highly chemo-, regio-, and stereoselective alkyne difunctionalization route to the synthesis of valuable (E)-silyl enallenes. The utility of this method is highlighted by late-stage derivatization of bioactive compounds.

Feasibility of microwave ablation of the vertebral growth plate for spine growth regulation: a preliminary study.

PURPOSE: To explore the feasibility of microwave ablation (MWA) of the vertebral growth plate as a minimally invasive treatment for early-onset scoliosis. MATERIALS AND METHODS: One side of the L1-L3 vertebral growth plates were ablated using different MWA powers. Ablation safety and size were examined. Subsequently, L1-L3 vertebral growth plates were ablated on one side for 40 s at 20 W. At 2, 4, and 6 weeks after the ablation, growth changes of the spine were observed. RESULTS: No piglets died during and after ablation, and all had modified Tarlov Grade 5. The safe MWA time (time for safely ablating the vertebral growth plate) was 17.0 ± 1.5 s at 50 W, 23.0 ± 2.3 s at 40 W, 31.0 ± 3.1 s at 30 W, 47.0 ± 3.7 s at 20 W, 70.0 ± 4.2 s at 15 W, and 158.0 ± 5.0 s at 10 W. With power <15 W, the vertebral growth plate could not be effectively ablated within the safe ablation time. Within the safe ablation times, the MWA size on hematoxylin and eosin slices on a transverse diameter was between 7 and 10 mm; and that on longitudinal diameter was mainly determined by the ablation needle length. Moreover, the growth plate and annulus fibrosus on the ablated side grew poorly over time, the vertebral body showed significant wedge-shaped changes, and the spine showed significant unbalanced growth. CONCLUSION: MWA of the vertebral growth plate can be performed safely when accompanied with appropriate thermometry, and could be a new minimally invasive strategy in regulating spine growth.

The Size Effects of Point Defect on the Mechanical Properties of Monocrystalline Silicon: A Molecular Dynamics Study.

The molecular dynamics method was used to simulate the fracture process of monocrystalline silicon with different sizes of point defect under a constant strain rate. The mechanism of the defect size on the mechanical properties of monocrystalline silicon was also investigated. The results suggested that the point defect significantly reduces the yield strength of monocrystalline silicon. The relationships between the yield strength variation and the size of point defect fitted an exponential function. By statistically analyzing the internal stress in monocrystalline silicon, it was found that the stress concentration induced by the point defect led to the decrease in the yield strength. A comparison between the theoretical strength given by the four theories of strength and actual strength proved that the Mises theory was the best theory of strength to describe the yield strength of monocrystalline silicon. The dynamic evolution process of Mises stress and dislocation showed that the fracture was caused by the concentration effect of Mises stress and dislocation slip. Finally, the fractured microstructures were similar to a kind of two-dimensional grid which distributed along the cleavage planes while visualizing the specimens. The results of this article provide a reference for evaluating the size effects of point defects on the mechanical properties of monocrystalline silicon.

Carbon-Decorated Na3V2(PO4)3 as Ultralong Lifespan Cathodes for High-Energy-Density Symmetric Sodium-Ion Batteries.

In this work, several carbon-decorated Na3V2(PO4)3 materials (NVP@C-750/800/850) are successfully fabricated using a sol-gel approach and subsequent heat treatment. When NVP@C-800 is used as a cathode, it shows an ultralong cycle life (2000 cycles) at a high rate of 10C, which is superior to the other two electrodes and those of reported NVP@C cathodes in the literature. The excellent results of NVP@C-800 are attributed to its nanostructure and the well-defined conductive carbon layer. The symmetric sodium (Na)-ion battery (SIB) with NVP@C-800 as both a cathode and an anode shows a high capacity at 40 mA g-1 with a voltage plateau of about 1.79 V and energy density of 113 W h kg-1, revealing that NVP@C is of great application prospect.

External-oxidant-free amino-benzoyloxylation of unactivated alkenes of unsaturated ketoximes with O-benzoylhydroxylamines.

A new copper-catalyzed two-component amino-benzoyloxylation of unactivated alkenes of unsaturated ketoximes with O-benzoylhydroxylamines as the benzoyloxy sources is developed. Chemoselectivity of this method toward amino-benzoyloxylation or oxy-benzoyloxylation of alkenyl ketoximes relies on the position of the tethered olefins, and provides an external-oxidant-free alkene difunctionalization route that directly utilizes O-benzoylhydroxylamines as the benzoyloxy radical precursors and internal oxidants for the divergent synthesis of cyclic nitrones and isoxazolines.

Programmed cell death-ligand 1 expression in hepatocellular carcinoma and its correlation with clinicopathological characteristics.

BACKGROUND AND AIM: Programmed cell death-ligand 1 (PD-L1) immunohistochemistry score has been approved as the predictive biomarker for anti-PD1/PD-L1 therapy in several advanced malignancies. Although its predictive role remained inconclusive in hepatocellular carcinoma, ongoing study of anti-PD1/PD-L1 therapy showed promising results. However, less is known about the PD-L1 immunohistochemistry score and factors correlated with it in hepatocellular carcinoma. We investigated PD-L1 immunohistochemistry scores in a large cohort of hepatocellular carcinoma, as well as its correlation with various clinical and genomic factors. METHODS: Immunohistochemistry was performed to detect the expression of PD-L1 protein in 315 hepatocellular carcinoma tissues. All slides were independently reviewed by three senior pathologists. Next-generation YS panel (450 genes) sequencing was performed on 309 patients. RESULTS: Higher PD-L1 expression as measured by combined positive score (CPS) was associated with increased Edmondson-Steiner grade (grade III vs II, P = 0.041) and TP53 mutations (P = 0.021). PD-L1 CPS had no correlation with tumor mutational burden (Spearman's correlation coefficient 0.067). PD-L1 CPS was not significantly associated with hepatitis B virus infection. CONCLUSIONS: Our data indicated that patients with higher Edmondson-Steiner grade (grade III) had significantly higher PD-L1 CPS than patients with lower Edmondson-Steiner grade (grade II). Patients with TP53 mutations had significantly higher PD-L1 expression.

Three-dimensional spiral CT observation of the facet joints of the lower cervical spine and its clinical significance.

OBJECTIVE: By observing the 3D anatomy of normal adult cervical facet joints, using the picture archiving and communication system to measure its 3D parameters and discussing its clinical significance, the aim of this study was to provide a reliable morphological basis for the design and manufacture of lower cervical facet joint interface distractors. METHODS: We selected 200 patients who underwent cervical spine 3D spiral computed tomography (CT) examination in the imaging department of our hospital from September 2019 to May 2020 and whose spiral CT images showed no cervical spinal canal stenosis, cervical disc herniation, obvious bone hyperplasia, or infection. The anterior and posterior diameters of the facet joints on both sides of the cervical spine, the space between the joints, and the left and right diameters were measured on the sagittal, cross-sectional and coronal planes after reconstruction with 3D spiral CT. RESULTS: The anterior and posterior diameters of the facet joints of the cervical spine, the space between the joints, and the left and right diameters all increased from top to bottom along the cervical spine. The 3D parameters of the C2-3~C6-7 segments were significantly different between the male and female groups. CONCLUSION: The anteroposterior diameter, joint space interval, and left and right diameter of cervical facet joints are different in each segment and between the sexes. The lower cervical facet joint interface fusion device designed according to the measurement results can fully meet the needs of most patients.

Methane emissions respond to soil temperature in convergent patterns but divergent sensitivities across wetlands along altitude.

Among the global coordinated patterns in soil temperature and methane emission from wetlands, a declining trend of optimal soil temperature for methane emissions from low to high latitudes has been witnessed, while the corresponding trend along the altitudinal gradient has not yet been investigated. We therefore selected two natural wetlands located at contrasting climatic zones from foothill and mountainside of Nepal Himalayas, to test: (1) whether the optimal temperature for methane emissions decreases from low to high altitude, and (2) whether there is a difference in temperature sensitivity of methane emissions from those wetlands. We found significant spatial and temporal variation of methane emissions between the two wetlands and seasons. Soil temperature was the dominant driver for seasonal variation in methane emissions from both wetlands, though its effect was perplexed by the level of standing water, aquatic plants, and dissolved organic carbon, particularly in the deep water area. When integrative comparison was conducted by adding the existing data from wetlands of diverse altitudes, and the latitude-for-altitude effect was taken into account, we found the baseline soil temperatures decrease whilst the altitude rises with respect to a rapid increase in methane emission from all wetlands, however, remarkably higher sensitivity of methane emissions to soil temperature (apparent Q10 ) was found in mid-altitude wetland. We provide the first evidence of an apparent decline in optimal temperature for methane emissions with increasing elevation. These findings suggest a convergent pattern of methane emissions with respect to seasonal temperature shifts from wetlands along altitudinal gradient, while a divergent pattern in temperature sensitivities exhibits a single peak in mid-altitude.