[Two new sesquiterpenes in Qi-nan Aquilariae Lignum Resinatum]

This study aimed to investigate the chemical constituents of supercritical extract from Qi-nan Aquilariae Lignum Resinatum by silica gel column chromatography, thin-layer chromatography, and semi-preparative high-performance liquid chromatography. One new elemane-type and one new eudesmane-type sesquiterpene compounds were isolated from the extract, and their structures were identified by MS, UV, IR, NMR, and ECD spectroscopic techniques, and named aquqinanol C(1) and aquqinanol D(2). Both compounds are novel compounds. The neuroprotective effect of the compounds on CORT-induced PC12 cell damage was determined in vitro. The results showed that compounds 1 and 2 exhibited a certain protective effect against CORT-induced damage in PC12 cells.

Clinicopathologic Features of Prostate Cancer with Mesorectal Lymph Node Involvement on PSMA or Fluciclovine PET/CT

PURPOSE/OBJECTIVE(S)

Advanced PET imaging has shown more prevalent mesorectal lymph node (LN) involvement in prostate cancer than previously appreciated. The clinical features predicting risk for mesorectal involvement are not well established and the prognostic impact is unclear. This may have implications on management including radiotherapy field design. This study aims to identify clinical and pathologic characteristics associated with mesorectal involvement identified on PSMA or fluciclovine PET/CT.

MATERIALS/METHODS

We conducted a single institution retrospective review of prostate cancer patients with F-18 fluciclovine, F-18 piflufolastat, or Ga-68 gozetotide PET between January 2020 and 2023 demonstrating tracer-avid mesorectal LN in the setting of newly diagnosed disease (ND) or biochemical failure after curative-intent therapy (BF). Clinical characteristics, pathologic findings, and early clinical outcomes were reviewed.

RESULTS

We identified 16 ND and 34 BF patients with uptake in at least one mesorectal LN on PET. For ND patients, clinical features at initial diagnosis were median PSA of 35.2 (range 9.6-659), median grade group 5, and 87% with clinical or radiographic T3/T4 disease. Radiographic PET staging among ND patients (excluding mesorectal LNs) were 19% N0M0, 25% N1M0, 56% as N1M1. For BF patients, clinical features at initial diagnosis were median PSA 9.2 (range 4.1-90) and median grade group 4. Primary treatment was prostatectomy in most (91%), with a high rate of high-risk features: 68% pT3-4, 28% pN1, and 32% had persistent detectable postop PSA. Radiographic PET staging among BF patients (excluding mesorectal LNs) were 29% N0M0, 38% N1M0, 12% N0M1, and 21% as N1M1. High-risk histologic features (cribriform, intraductal, ductal, or neuroendocrine) were identified in 88% of ND and 48% BF patients. Of these patients, 86% had cribriform pattern. Median PSA prior to PET for ND and BF patients was 37.0 (range 8.5-659) and 1.9 (0.2-11.1). Median interval from initial therapy to PET for BF patients was 4.4yr (range 0.2-19.7). Median follow-up post-PET was 8.7mo (range 3.4-29) for ND and 8.8mo (range 0-76) for BF patients. Of patients with M0 PET staging, none of the 7 ND patients developed DMs, and 1 of 23 BF patients developed DM after 4 yrs.

CONCLUSION

In this analysis of prostate cancer patients with mesorectal involvement, we found a high incidence of high grade, T3-4 disease, and cribriform pattern, especially in ND patients. For BF patients, there was a high incidence of pT3-4 and pN1 disease at time of initial treatment. Overall, most patients had concurrent regional nodal disease on PET. Longer follow up of clinical outcomes and comparison to high-risk patients without mesorectal LN involvement is needed to understand the prognostic significance and predictors of mesorectal LN spread. Additional studies are needed to identify patients at highest risk in whom elective coverage of mesorectal lymphatics with elective pelvic nodal RT may be warranted.

One-pot solvothermal synthesis of In-doped amino-functionalized UiO-66 Zr-MOFs with enhanced ligand-to-metal charge transfer for efficient visible-light-driven CO2 reduction

Metal organic frameworks (MOFs) with high porosity and highly tunable physical/chemical properties can serve as heterogeneous catalysts for CO₂ photoreduction, but the application is hindered by the large band gap (E_g) and insufficient ligand-to-metal charge transfer (LMCT). In this study, a simple one-pot solvothermal strategy is proposed to prepare an amino-functionalized MOF (aU(Zr/In)) featuring an amino-functionalizing ligand linker and In-doped Zr-oxo clusters, which enables efficient CO₂ reduction driven with visible light. The amino functionalization leads to a significant reduction of E_g as well as a charge redistribution of the framework, allowing the absorption of visible light and the efficient separation of photogenerated carriers. Furthermore, the incorporation of In not only promotes the LMCT process by creating oxygen vacancies in Zr-oxo clusters, but also greatly lowers the energy barrier of the intermediates for CO₂-to-CO conversion. With the synergistic effects of the amino groups and the In dopants, the optimized aU(Zr/In) exhibits a CO production rate of 37.58 ± 1.06 μmol g^-1 h^-1, outperforming the isostructural University of Oslo-66- and Material of Institute Lavoisier-125-based photocatalysts. Our work demonstrates the potential of modifying MOFs with ligands and heteroatom dopants in metal-oxo clusters for solar energy conversion.

Ligand Conformation Fixation Strategy for Expanding the Structural Diversity of Copper-Tricarboxylate Frameworks and C2H2 Purification Performance Studies

Structural and functional expansion of metal-organic frameworks (MOFs) is fundamentally important because it not only enriches the structural chemistry of MOFs but also facilitates the full exploration of their application potentials. In this work, by employing a dual-site functionalization strategy to lock the ligand conformation, we designed and synthesized a pair of biphenyl tricarboxylate ligands bearing dimethyl and dimethoxy groups and fabricated their corresponding framework compounds through coordination with copper(II) ions. Compared to the monofunctionalized version, introduction of two side groups can significantly fix the ligand conformation, and as a result, the dual-methoxy compound exhibited a different network structure from the mono-methoxy counterpart. Although only one almost orthogonal conformation was observed for the two ligands, their coordination framework compounds displayed distinct topological structures probably due to different solvothermal conditions. Significantly, with a hierarchical cage-type structure and good hydrostability, the dimethyl compound exhibited promising practical application value for industrially important C₂H₂ separation and purification, which was comprehensively demonstrated by equilibrium/dynamic adsorption measurements and the corresponding Clausius-Clapeyron/IAST/DFT theoretical analyses.

One-pot solvothermal synthesis of flower-like Fe-doped In2S3/Fe3S4 S-scheme hetero-microspheres with enhanced interfacial electric field and boosted visible-light-driven CO2 reduction

S-scheme heterojunctions hold great potential for CO2 photoreduction into solar fuels, but their activities are severely limited by the low efficiency of interfacial charge transfer. In this work, a facile one-pot solvothermal reaction has been developed to dope Fe into flower-like In2S3/Fe3S4 hetero-microspheres (Fe-In2S3/Fe3S4 HMSs), which are demonstrated as an efficient S-scheme photocatalyst for visible-light-driven CO2 photoreduction. The doping of Fe not only reduces the bandgap of In2S3 and thus extends the optical response to the visible-light region, but also increases the densities of donors and sulfur vacancies, which leads to an elevated Fermi level (Ef). The difference of Ef between In2S3 and Fe3S4 is enlarged and their band bending at the interface is therefore enhanced, which results in promoted carriers transfer in the S-scheme pathway due to the reinforced interfacial electric field. Moreover, Fe-doped In2S3 reduces the formation energy of the *CO intermediate, which thermodynamically favors the CO evolution at the surface. As a result, the Fe-In2S3/Fe3S4 HMSs exhibit a significantly boosted CO2 photoreduction activity in comparison with bare In2S3 and Fe-In2S3 samples. This work demonstrates the great potential of heteroatom-engineered S-scheme photocatalysts for CO2 photoreduction.

Substituent Engineering-Enabled Structural Rigidification and Performance Improvement for C2/CO2 Separation in Three Isoreticular Coordination Frameworks

Construction of porous solid materials applied to the adsorptive removal of CO₂ from C₂ hydrocarbons is highly demanded thanks to the important role C₂ hydrocarbons play in the chemical industry but quite challenging owing to the similar physical parameters between C₂ hydrocarbons and CO₂. In particular, the development of synthetic strategies to simultaneously enhance the uptake capacity and adsorption selectivity is very difficult due to the trade-off effect frequently existing between both of them. In this work, a combination of the dicopper paddlewheel unit and 4-pyridylisophthalate derivatives bearing different substituents afforded an isoreticular family of coordination framework compounds as a platform. Their adsorption properties toward C₂ hydrocarbons and CO₂ were systematically investigated, and subsequent IAST and density functional theory calculations combined with column breakthrough experiments verified their promising potential for C₂/CO₂ separations. Furthermore, the substituent engineering endowed the resulting compounds with simultaneous enhancement of uptake capacity and adsorption selectivity and thus better C₂/CO₂ separation performance compared to their parent compound. The substituent introduction not only mitigated the framework distortion via fixing the ligand conformation for establishment of better permanent porosity required for gas adsorption but also polarized the framework surface for host-guest interaction improvement, thus resulting in enhanced separation performance.

Callnudoids A-H: Highly modified labdane diterpenoids with anti-inflammation from the leaves of Callicarpa nudiflora

Eight undescribed 3,4-seco-norlabdane diterpenoids, callnudoids A-H, as well as two known analogues were isolated from the leaves of Callicarpa nudiflora. The structures were elucidated using spectroscopic methods and were compared with published NMR spectroscopic data. The absolute configurations of callnudoids D and E were defined based on ECD data or single-crystal X-ray diffraction. Callnudoids A-C are the highly modified labdane diterpenoids featuring rearranged 3,4-seco-ring and the formation of an undescribed cyclohexene moiety via C2-C18 cyclization. They only contain 15 carbon atoms on the carbon skeleton. Callnudoid D represents the unusual 3,4-seco-15,16-norlabdane diterpenoid with C13-C17 cyclization, and a putative biosynthesis pathway for callnudoids A, B, D, and E was proposed. All compounds were evaluated for their anti-inflammatory activities by inhibiting the lipopolysaccharide (LPS)-induced nitric oxide (NO) released in RAW264.7 cells; callnudoids A-E and H, and methylcallicarpate obviously inhibited pro-inflammatory cytokines TNF-α and IL-1β in a dose-dependent manner.

Theoretical understanding on all-solid frustrated Lewis pair sites of C2N anchored by single metal atom

Designing all-solid heterogeneous catalysts with frustrated Lewis pairs (FLPs) has aroused great attentions recently because of its appealing low dissociation energy for H2 molecule and thus a promotion of hydrogenation reaction is expected. The sterically encumbered Lewis acid (metal site) and base (nitrogen site) in the cavity of single transition metal atom doped M/C2N sheet makes it potential candidate with FLP, while a comprehensive understanding of its intrinsic property and reactivity is still required. Calculations show that the complete dissociation of H2 molecule into two H* at the N sites requires two steps, i.e., heterolytic cleavage of H2 molecule and the transfer of H* from metal site to N site, which are highly related to the acidity of the metal site. The Ni/C2N and Pd/C2N, which outperform over the other 8 transition metal atom (M) anchored M/C2N candidates, possess low energy barriers for the complete dissociation of H2 molecule, with values of only 0.30 and 0.20 eV, respectively. Furthermore, both Ni/C2N and Pd/C2N catalysts can achieve semi-hydrogenation of C2H2 into C2H4, with overall barriers of 0.81 and 0.75 eV, respectively, lower than many reported catalysts. It is speculated that M/C2N catalysts with intrinsic FLPs may also find applications in other important hydrogenation reaction.

Mechanism of Catalytic Transfer Hydrogenation for Furfural Using Single Ni Atom Catalysts Anchored to Nitrogen-Doped Graphene Sheets

Catalytic transfer hydrogenation (CTH) of α,β-unsaturated aldehydes using single metal atom catalysts supported on nitrogen-incorporated graphene sheet (M-N_x-Gr) materials has attracted increasing attention recently, yet the reaction mechanism remains to be explored. Compared to the Ni-N₄-Gr model in which the dissociation of isopropanol is highly unfavorable as a result of steric hindrance and inertness of the Ni-N₄ site embedded in graphene, the Ni-N₃ site in Ni-N₃-Gr is more active and facilitates the formation of *H with isopropanol as the H donor, where the dissociation of H from isopropanol with an energy barrier of 0.83 eV is the rate-determining step. An alternative reaction path starts from the coadsorption of isopropanol and furfural molecules at the Ni-N₃ site, followed by a direct hydrogen transfer between the two molecules; however, the rate-determining step has a much higher energy barrier of 1.32 eV. Our calculations suggest that the hydrogenation of the aldehyde group is kinetically more favorable than the C═C hydrogenation, revealing the high chemoselectivity of furfural to furfuryl alcohol. Our investigations reveal that the CTH mechanism using the Ni-N₃-Gr catalyst is different from that on traditional metal oxides, where the former has only one single active site, while two active sites are required for the latter. The proposed reaction mechanism of CTH for furfural in this study should be helpful to guide the design of single metal atom catalysts with appropriate N coordination for application in chemoselective hydrogenation reactions.

Perspective on Defective Semiconductor Heterojunctions for CO2 Photoreduction

Photocatalytic CO₂ reduction to value-added chemicals is a green solution to concurrently address CO₂ emission and energy issues, and semiconductor heterojunctions hold great potential to achieve such conversion. However, the photocatalytic performance of the existing heterojunctions is limited by the low interfacial charge transfer efficiency and sluggish surface reaction kinetics. To overcome these obstacles, defect engineering has been applied to heterojunctions to boost CO₂ photoreduction in the past 5 years. This perspective summaries the key roles and the related mechanism of various anion vacancies located at the surface, interface, and both surface and interface of heterojunctions in photocatalytic CO₂ reduction. Challenges in constructing and characterizating defective heterojunctions as well as in promoting their CO₂ photoreduction activity and hydrocarbon selectivity are then outlined. Finally, some solutions to the rational design of defective heterojunctions for efficient and stable CO₂ photoreduction are also proposed.

ZnSe Nanorods-CsSnCl3 Perovskite Heterojunction Composite for Photocatalytic CO2 Reduction

Utilizing sunlight to convert CO₂ into chemical fuels could simultaneously address the greenhouse effect and fossil fuel crisis. ZnSe nanocrystals are promising candidates for photocatalysis because of their low toxicity and excellent photoelectric properties. However, pristine ZnSe generally has low catalytic activities due to serious charge recombination and the lack of efficient catalytic sites for CO₂ reduction. Herein, a ZnSe nanorods-CsSnCl₃ perovskite (ZnSe-CsSnCl₃) type II heterojunction composite is designed and prepared for photocatalytic CO₂ reduction. The ZnSe-CsSnCl₃ type II heterojunction composite exhibits enhanced photocatalytic activity for CO₂ reduction with respect to pristine ZnSe nanorods. The experimental characterizations and theoretical calculations reveal that the efficient charge separation and lowered free energy of CO₂ reduction facilitate the CO₂ conversion on the ZnSe-CsSnCl₃ heterojunction composite. This work presents a type II heterojunction composite photocatalyst based on ecofriendly metal chalcogenides and metal halide perovskites. Our study has also promoted the understanding of the CO₂ reduction mechanisms on perovskite nanocrystals, which could be valuable for the development of metal halide perovskite photocatalysts.

Cadinane-Type Sesquiterpenoids with Cytotoxic Activity from the Infected Stems of the Semi-mangrove Hibiscus tiliaceus

Eight new cadinane sesquiterpenoids (1-8), along with two known compounds (9 and 10), were isolated from infected stems of the semi-mangrove plant, Hibiscus tiliaceus. The structures of compounds 1-8 were elucidated through the analysis of their 1D and 2D NMR and MS data, and their absolute configurations were determined by comparing their experimental and calculated ECD spectra and by single-crystal X-ray diffraction. The two confused known compounds (9 and 10) were resolved using single-crystal X-ray crystallography. Compounds 1-3 have novel norsesquiterpene carbon skeletons arising from a ring contraction rearrangement. All obtained isolates were evaluated against the HepG2 and Huh7 cell lines, and compounds 1b, 2b, 4, 6, and 8 showed cytotoxic activity toward both cell lines, with IC₅₀ values ranging from 3.5 to 6.8 μM.

Highly dispersed palladium nanoclusters anchored on nanostructured hafnium(iv) oxide as highly efficient catalysts for the Suzuki–Miyaura coupling reaction

Pd@HfO2 derived via two-step pyrolysis of Pd@NH2-UiO-66(Hf) exhibited high catalytic activity for the Suzuki–Miyaura coupling reactions.

[Effect of peritoneum reconstruction on postoperative complications after laparoscopic low anterior resection for rectal cancer]

Objective: To determine the effect of peritoneum reconstruction on postoperative complications after laparoscopic low anterior resection (LAR) for rectal cancer. Methods: Retrospective cohort study and propensity score matching were conducted. Case inclusion criteria: (1) pathologically confirmed rectal adenocarcinoma; (2) 18 to 80 years; (3) patients with middle to low rectal cancer undergoing laparoscopic LAR; (4) patients staging cT1-4aN0-2M0 or ycT1-4aN0-2M0 after neoadjuvant therapy; (5) the distance of 4-10 cm from tumor low margin to anal verge. Exclusion criteria: (1) abdominal surgery history (except appendicitis, cholecystitis, ectopic pregnancy); (2) anastomosis above the peritoneal reflection; (3) tumor distant metastasis or clinical staging of T4b during surgery; (4) conversion to open surgery; (5) severe incapacitating disease (American Society of Anesthesiologists classification IV or V, ASA). A total of 666 patients with middle to low rectal cancer undergoing laparoscopic LAR in The First Affiliated Hospital of Army Medical University from January 2017 to June 2020 were enrolled. There were 473 males and 193 females with the median age of 59 (18-80) years. Laparoscopic LAR with peritoneum reconstruction was performed in 188 cases (PR group), and laparoscopic LAR without peritoneum reconstruction was performed in 478 cases (NPR group). After 1:1 propensity score matching according to 1:1 based on age, gender, body mass index, TNM staging, ASA classification, intraoperative blood loss, distance from tumor low margin to anal edge, 153 cases were included in each group. Postoperative complications were classified according to Clavien-Dindo classification. Anastomotic leakage was defined and graded according to the International Study Group of Rectal Cancer (ISGRC) criteria. Results: After propensity score matching, there were no significant differences in baseline demographic characteristics between the 2 groups (all P>0.05), indicating that these two groups were comparable. (1) Operative conditions: All the patients in both groups completed operation successfully. Compared with the NPR group, the PR group had longer operation time [(181.3±60.3) minutes vs. (168.9±51.5) minutes, t=2.185, P=0.029], shorter postoperative median hospital stay [8 (7, 10) days vs. 9 (7, 11) days, Z=-2.282, P=0.022], and the differences were statistically significant (P<0.05). (2) Postoperative complications: The overall morbidity of postoperative complication in PR group and NPR group was 20.3% (31/153) and 24.2% (37/153) respectively, and the incidence of anastomotic leakage was 9.8% (15/153) and 11.1%(17/153) respectively, whose differences were not statistically significant (both P>0.05). Compared with NPR group, PR group had lower morbidity of grade III to IV complications [3.9% (6/153) vs. 11.1% (17/153), χ(2)=5.688, P=0.017] and lower secondary operation rate [1.3% (2/153) vs. 5.9% (9/153), χ(2)=4.621, P=0.032], the differences were statistically significant (both P<0.05). Though PR group had lower incidence of grade C anastomoic leakage [1.3% (2/153) vs. 3.9% (6/153), χ(2)=2.054, P=0.152], but the differences were not statistically significant. (3) Postoperative inflammation: The difference of the procalcitonin level of both PR and NPR groups at postoperative 1-d, 3-d, and 5-d was statistically significant (F=5.222, P=0.010) in time-dependent manner, while the difference was not significant in the interaction effect (P>0.05). No statistically significant differences in the C-reactive protein level between two groups at postoperative 1-d, 3-d, and 5-d were found (all P>0.05). Conclusion: Peritoneum reconstruction in laparoscopic LAR can decrease the morbidity of postoperative complication of grade III to IV and the reoperation rate, and plays an important role in controlling the inflammatory reaction, which has great clinical value.

[Molecular characteristics of Legionella pneumophila in shower water of public places in Ma'anshan city from 2019 to 2020]

Objective: To understand the epidemiological and pathogenic characteristics of Legionella pneumophila in shower water of public places in Ma'anshan City from 2019 to 2020, and to provide scientific basis for further prevention and control of legionellosis. Methods: From 2019 to 2020, according to population density distribution and business scale of bathing places in the main urban area of Ma'anshan City (Huashan District and Yushan District), 8 public bathing places (including 3 large, 3 medium and 2 small) were selected to collect 308 shower water and water storage pool water samples (294 shower water samples and 14 water storage pool water samples). After the collected water samples were treated, cultured, isolated and identified, the type characteristics of Legionella pneumophila were analyzed. Results: Legionella pneumophila were detected in 120 water samples among 308 shower water and water storage pool water samples, with an overall positive rate of 39.0% (120/308). A total of 154 Legionella pneumophila strains were detected, including 10 different serotypes, predominated by serotype 1 (LP1) and serotype 3 (LP3), accounting for 40.9% (63/154) and 22.7% (35/154). Among 154 strains of Legionella pneumophila, 23 strains of Legionella pneumophila were positive for all 14 virulence genes, accounting for 14.9% (23/154), including 19 serotype 1 (LP1) and 4 serotype 8 (LP8). Pulsed field gel electrophoresis (PFGE) cluster analysis of 154 Legionella pneumophila strains showed 60 different patterns. Conclusion: Legionella pneumophila was seriously polluted in the shower water environment of public places in Ma^, anshan City. The serotypes are widely distributed and the virulence of the strains is strong. The results of molecular typing show that these strains have genetic diversity.

Single non-noble metal atom doped C2N catalysts for chemoselective hydrogenation of 3-nitrostyrene

Improving the reaction selectivity and activity for challenging substrates such as nitroaromatics bearing two reducible functional groups is important in industry, yet remains a great challenge using traditional metal nanoparticle based catalysts. In this study, single metal atom doped M-C₂N catalysts were theoretically screened for selective hydrogenation of 3-nitrostyrene to 3-vinylaniline with H₂ as the H-source. Among 20 M-C₂N catalysts, the non-noble Mn-C₂N catalyst was found to have excellent reaction selectivity. Importantly, due to the solid frustrated Lewis pair sites in the pores of Mn-C₂N, a low H₂ activation energy is achieved on high-spin Mn-C₂N and the rate-determining step for the hydrogenation reactions is the H diffusion from the metal site to the N site. The unraveled mechanism of the hydrogenation of 3-nitrostyrene using Mn-C₂N enriches the applications of Mn based catalysts and demonstrates its excellent properties for catalyzing the challenging hydrogenation reaction of substrates with two reducible functional groups.

Improving Ethane/Ethylene Separation Performance of Isoreticular Metal-Organic Frameworks via Substituent Engineering

The preferential capture of ethane (C₂H₆) over ethylene (C₂H₄) presents a very cost-effective and energy-saving means applied to adsorptive separation and purification of C₂H₄ with a high product purity, which is however challenged by low selectivity originating from their similar molecular sizes and physical properties. Substituent engineering has been widely employed for selectivity regulation and improvement, but its effect on C₂H₆/C₂H₄ separation has been rarely explored to date. In this work, four isoreticular coordination framework compounds based on 5-(pyridin-3-yl)isophthalate ligands bearing different substituents were rationally constructed. As revealed by isotherm measurements, thermodynamic studies, and IAST computations, they exhibited promising utility for C₂H₆/C₂H₄ separation with moderate adsorption heat and a high uptake amount at a relatively low-pressure domain. Furthermore, the C₂H₆/C₂H₄ separation potential can be finely tuned and optimized via purposeful substituent alteration. Most remarkably, functionalization with a nonpolar methyl group yielded an improved separation efficiency compared to its parent compound. This work offers a good reference value for enhancing the C₂H₆/C₂H₄ separation efficiency of MOFs by engineering the pore microenvironment and dimensions via substituent manipulation.

Hepatic perivascular epithelioid cell tumor: Clinicopathological analysis of 26 cases with emphasis on disease management and prognosis

BACKGROUND

Perivascular epithelioid cell tumor (PEComa) is an uncommon tumor of mesenchymal origin. Cases of PEComa in the liver are extremely rare.

AIM

To analyze the clinicopathological features and treatment of hepatic PEComa and to evaluate the prognosis after different treatments.

METHODS

Clinical and pathological data of 26 patients with hepatic PEComa were collected. All cases were analyzed by immunohistochemistry and clinical follow-up.

RESULTS

This study included 17 females and 9 males, with a median age of 50 years. Lesions were located in the left hepatic lobe in 13 cases, in the right lobe in 11, and in the caudate lobe in 2. The median tumor diameter was 6.5 cm. Light microscopy revealed that the tumor cells were mainly composed of epithelioid cells. The cytoplasm contained heterogeneous eosinophilic granules. There were thick-walled blood vessels, around which tumor cells were radially arranged. Immunohistochemical analysis of pigment-derived and myogenic markers in PEComas revealed that 25 cases were HMB45 (+), 23 were Melan-A (+), and 22 SMA (+). TFE3 and Desmin were negative in all cases. All the fluorescence in situ hybridization samples were negative for TFE3 gene break-apart probe. Tumor tissues were collected by extended hepatic lobe resection or simple hepatic tumor resection as the main treatments. Median follow-up was 62.5 mo. None of the patients had metastasis or recurrence, and there were no deaths due to the disease.

CONCLUSION

Hepatic PEComa highly expresses melanin and smooth muscle markers, and generally exhibits an inert biological behavior. The prognosis after extended hepatic lobe resection and simple hepatic tumor resection is semblable.

Structural Revisions of Two Highly Aromatic Naphthoquinone-Derived Dimers Based on NMR Analysis, Computer-Assisted Structure Elucidation Methods, and Computations

Eleucanainones A and B are two structurally complex naphthoquinone-derived dimers whose structure identification is difficult. Large yellow fragments of the preliminary CASE (computer-assisted structure elucidation) analysis revealed that the original structures might be questionable. Structural revisions of the two compounds were proposed on the basis of NMR analysis, CASE methods, conformation analysis, and DFT (density functional theory) NMR calculations with a custom DP4+ analysis. In addition, a polyketide-folded biosynthetic pathway of the two revised structures was proposed.

Atomically Dispersed Vanadium Sites Anchored on N-Doped Porous Carbon for the Efficient Oxidative Coupling of Amines to Imines

Single-atom catalysts effectively integrate the respective advantages of homogeneous and heterogeneous catalysts and are a pioneering research frontier in catalysis by virtue of their maximized utility of metal atoms and distinct atomic configuration. However, development of such catalysts is still in the early stages. Herein, atomically dispersed vanadium (V) sites that are coordinated by N atoms and inlaid within N-incorporated porous carbon networks were prepared through a top-down strategy by annealing a V-containing metal-organic framework, NH₂-MIL-101(V), followed by acid etching. The resulting V-N-C-600 catalyst exhibits unexpected catalytic reactivity, selectivity, and robust stability for the direct aerobic oxidation of benzylamine to generate N-benzylidene benzylamine with molecular oxygen under mild conditions. The turnover frequency reaches 53.9 h^-1, which is much superior to those achieved over the commercial V₂O₅ and state-of-the-art non-noble metal heterogeneous catalysts reported in the literature. Kinetic analysis reveals a low activation energy barrier (37 kJ mol^-1) for the benzylamine oxidation and indicates that a carbocationic intermediate is involved in the reaction mechanism. The synergistic effect between the isolated V single-atomic sites and N-doped hierarchically porous carbon network boosts the performance of V-N-C-600. Moreover, V-N-C-600 exhibits a wide generality for the efficient synthesis of a set of symmetrical imines, unsymmetrical imines, and imine derivatives.

An aromatic-rich cage-based MOF with inorganic chloride ions decorating the pore surface displaying the preferential adsorption of C2H2 and C2H6 over C2H4

An aromatic-rich chloride-embedded nanocage-based MOF displayed an unusual adsorption relationship towards C₂ hydrocarbons, with the potential for C₂H₄ separation and purification application.

Natural Nitrogenous Sesquiterpenoids and Their Bioactivity: A Review

Nitrogenous sesquiterpenoids fromnatural sourcesare rare, so unsurprisingly neither the potentially valuable bioactivity nor thebroad structural diversity of nitrogenous sesquiterpenoids has been reviewed before. This report covers the progressduring the decade from 2010 to February 2020 on the isolation, identification, and bioactivity of 391 nitrogen-containing natural sesquiterpenes from terrestrial plant, marine organisms, and microorganisms. This complete and in-depth reviewshouldbe helpful for discovering and developing new drugs of medicinal valuerelated to natural nitrogenous sesquiterpenoids.

Preparation of CaF2 Microspheres with Nanopetals for Water Vapor Adsorption

The hierarchically structured flower-like CaF₂ microspheres with nanopetals, named FL-CaF₂, were synthesized via a hydrothermal method using calcium acetate Ca(Ac)₂ and NaBF₄ as calcium and fluorine sources, respectively, assisted by the chelating reagent trisodium citrate (Na₃Cit) with the optimal pH of the synthesis solution. Meanwhile, a reference sample, named FL-CaF₂-R, was reproduced using ethylenediaminetetraacetic acid disodium salt (Na₂EDTA) as the chelating reagent, based on the recipe and synthesis procedure from the literature. Various techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform-infrared spectroscopy, and N₂ adsorption-desorption at 77 K were then used to characterize the synthesized samples. The results show that FL-CaF₂ with a larger diameter has a much higher thermal stability than FL-CaF₂-R because the larger the nanocrystallite size, the higher the thermal stability. The adsorption of water vapor on CaF₂ is irreversible because CaF₂ can interact with the adsorbed water molecules strongly. The dual-site Langmuir model was used to describe the measured adsorption isotherms of water vapor on FL-CaF₂ at low water vapor pressures and 298, 308, and 318 K. FL-CaF₂ has a much higher water-adsorption capacity than those reported in the literature. Furthermore, the isosteric heat of adsorption as a function of loading, derived from the measured isotherms, varies from ca. 46 to 43 kJ mol^-1 in the whole loading range investigated. Finally, the applications of FL-CaF₂ are anticipated in the dehydration of hydrogen fluoride gas as well as in catalysis.

Role of hydrogen bond capacity of solvents in reactions of amines with CO2: A computational study

Various computational methods were employed to investigate the zwitterion formation, a critical step for the reaction of monoethanolamine with CO₂, in five solvents (water, monoethanolamine, propylamine, methanol and chloroform) to probe the effect of hydrogen bond capacity of solvents on the reaction of amine with CO₂ occurring in the amine-based CO₂ capture process. The results indicate that the zwitterion can be formed in all considered solvents except chloroform. For two pairs of solvents (methanol and monoethanolamine, propylamine and chloroform) with similar dielectric constant but different hydrogen bond capacity, the solvents with higher hydrogen bond capacity (monoethanolamine and propylamine) facilitate the zwitterion formation. More importantly, kinetics parameters such as activation free energy for the zwitterion formation are more relevant to the hydrogen bond capacity than to dielectric constant of the considered solvents, clarifying the hydrogen bond capacity could be more important than dielectric constant in determining the kinetics of monoethanolamine with CO₂.

Kinking and cracking behavior in nacre under stepwise compressive loading

The damage evolution of nacre under compressive loading has not been well understood, despite numerous investigations on its compressive behavior. In the present work, quasi-in-situ loading-unloading-reloading stepwise compressive tests were performed on nacre in Pinctada maxima shell, which exhibits a distinctive gradient feature with the thickness of platelets decreasing from the external to internal parts. In the loading direction parallel to the platelets, multiple microcracks and kink bands can absorb much deformation energy, leading to a graceful failure. Kinking only occurs at the final stage of fracture process, and it thus has no obvious influence on the strength of nacre, but contributes to a much larger strain. In the loading direction perpendicular to the platelets, nacre exhibits concurrently much higher compressive strength and fracture strain, as the damage can be effectively restricted. This is attributed to the presence of gradient structure, which disperses the stress concentration in front of the crack tip, and arouses the toughening mechanisms including damage localization and crack deflection. The findings obtained in this study are expected to provide fundamental insights into the design of bio-inspired advanced engineering materials.

AnN-oxide-functionalized nanocage-based copper-tricarboxylate framework for the selective capture of C2H2

AnN-oxide-functionalized copper-tricarboxylate framework displayed promising potential for use in C₂H₄and C₂H₂purification.

[Anti-inflammatory sesquiterpenes from agarwood produced via whole-tree agarwood-inducing technique of Aquilaria sinensis]

The present study is to investigate the chemical constituents and anti-inflammation of agarwood produced via whole-tree agarwood-inducing technique( Agar-Wit) from Aquilaria sinensis by column chromatographic technique and semi-preparation HPLC.Eleven sesquiterpenes were isolated from the agarwood produced by Agar-Wit,and their structures were identified on the basis of physiochemical characteristics and spectroscopic data analysis as baimuxinol( 1),5α,7α( H)-eudesm-11( 13)-en-4α-ol( 2),( 7 S,9 S,10 S)-( +)-9-hydroxy-selina-4,11-dien-14-al( 3),petafolia A( 4),7( 11)-eremophilen-8-one( 5),neopetasane( 6),petafolia B( 7),11-hydroxy-valenc-1( 10)-en-2-one( 8),( 4αβ,7β,8αβ)-3,4,4α,5,6,7,8,8α-octahydro-7-[1-( hydroxymethyl) ethenyl]-4α-methylnaphthalene-1-carboxaldehyde( 9),12-hydroxy-4( 5),11( 13)-eudesmadien-15-al( 10),and( 4 R,5 R,7 S,9 S,10 S)-(-)-eudesma-11( 13)-en-4,9-diol( 11). Among them,compound 1 was a new natural product,and this is the first time to report its13 CNMR spectroscopic data. Compounds 4,9 and 10 were reported from Aquilaria for the first time,and all the compounds are firstly isolated by Agar-Wit from A. sinensis. The anti-inflammatory activity of RAW264. 7 cells with lipopolysaccharide-induced was evaluated.As a result,1,4 and 9 showed potential anti-inflammatory activities with IC50 values( 2. 5±0. 35),( 3. 2±0. 2),( 4. 3±0. 56) μmol·L^-1,respectively. This work provided scientific foundation for quality evaluation of the agarwood produced by Agar-Wit.

Sesquiterpenoids with cytotoxicity from heartwood of Dalbergia odorifera

Two new sesquiterpenoids, named dalodorin A (1) and dalodorin B (2), together with four known sesquiterpenoids, were isolated from the heartwood of Dalbergia odorifera. Their structures were elucidated on the basis of spectroscopic analysis including 1D and 2D NMR techniques and HR-ESI-MS. Evaluation of the isolated compounds for cytotoxicity against two human cancer cell lines (Hela and HepG-2) showed moderate activities (25.22-60.45 μM).

Two novel diterpenes from the stems and leaves of tropical seagrass Enhalus acoroides in the South China sea

Two novel diterpenes Enhoidin A (1) and Enhoidin B (2) featuring an unusual gibberellane skeleton were isolated from the stems and leaves of Enhalus acoroides. Their structures were elucidated on the basis of spectroscopic analysis including 1D and 2D NMR techniques and HR-ESI-MS. This is the first time that this type of lactone ring between C-18 and C-20 has been found among gibberellanes from the tropical seagrasses. Evaluation of the all compounds for cytotoxicity against four human cancer cell lines (MCF-7, HCT-116, HepG-2 and HeLa), and showed moderate cytotoxic activities.

A new bis-γ-pyrone polypropionate from a marine pulmonate mollusc Onchidium struma

A new bis-γ-pyrone polypropionate compound onchidione II (1), together with three known compounds, was isolated from a marine pulmonate mollusc Onchidium struma, collected at Hainan Island of China. The structure of new compound was determined by extensive spectroscopic analyses including IR, 1D and 2D NMR techniques, and chemical methods. Compounds 1-4 were evaluated for their cytotoxicity against human tumor cell lines HepG-2, A549, and MCF-2. The results showed that compounds 1 and 2 were moderate cytotoxic against HepG-2, A549, and MCF-2 cell lines, with IC₅₀ values from 13.2 to 22.4 μM.

Benzyne-mediated trichloromethylation of chiral oxazolines

A three-component reaction between benzyne, oxazolines and chloroform was developed for the synthesis of trichloromethylated chiral oxazolidines.

Deformation and fracture behavior of a natural shell ceramic: Coupled effects of shell shape and microstructure

Common seashells possess their most adaptive functions benefiting from the macro-geometry and unique microstructures. The Cymbiola nobilis shell exhibits a logarithmic spiral-like shape and it is hierarchically constructed by the fiber-like crossed-lamellar structure. Three-point bending tests are conducted on three groups of samples taken from different locations (G1 with two macro-layers, G2 with three macro-layers, and G3 containing three macro-layers but with an arch-like curved shape). A novel method was developed to evaluate the bending stress of the curved samples and understand the bending fracture resistance of such curved samples. Due to the presence of a horizontal force that can decrease or shield the bending moment at the bottom center of samples, the arch-like G3 samples demonstrate the highest bending fracture resistance, revealing the significance of the curved shape of shell in the protection against the external attacks. The number of macro-layers and the curved shape of shell play an important role in the mechanical properties of the shell. The orientation of building blocks in a single crossed-lamellar layer is critical to the fracture resistance, and five types of fracture modes based on interfacial debonding, inter- and trans-lamella fracture are identified. The results obtained in this study would help open a new pathway to the development of bio-inspired high-performance structural materials.

[A new naphthalene derivative from bulbs of Eleutherine americana]

A new naphthalene derivative and three known compounds were isolated from the petroleum ether extract of the bulbs of Eleutherine americana by using various chromatographic techniques, such as column chromatography over silica gel and semi-preparative HPLC. Their structures were elucidated by spectroscopic date (MS, UV, IR, NMR), which were identified as eleutherol B (1), 4,8-dihydroxy-3-methoxy-1-methylanthraquinone-2-carboxylic acid methyl ester (2), 8-hydroxy-3,4-dimethoxy-1-methylanthraquinone-2-carboxylic acid methyl ester (3), and isoeleutherine (4). Compound 1 is a new compound. The diastolic blood vessels activity of compound 1 and 2 were potent, reaching 82.5% and 85.3% at the concentration of 10 μmol·L⁻¹, which were basically the same as that of the positive drug tanshinone ⅡA.

Thermodynamic and microstructural study of Ti2AlNb oxides at 800 °C

The high-temperature structural applications of Ti2AlNb-based alloys, such as in jet engines and gas turbines, inevitably require oxidation resistance. The objective of this study is to seek fundamental insight into the oxidation behavior of a Ti2AlNb-based alloy via detailed microstructural characterization of oxide scale and scale/substrate interface after oxidation at 800 °C using X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe microanalysis (EPMA), and transmission electron microscopy (TEM). The oxide scale exhibits a complex multi-layered structure consisting of (Al,Nb)-rich mixed oxide layer (I)/mixed oxide layer (II)/oxygen-rich layer (III)/substrate from the outside to inside, where the substrate is mainly composed of B2 and O-Ti2AlNb phases. High-resolution TEM examinations along with high-angle annular dark-field (HAADF) imaging reveal: (1) the co-existence of two types (α and δ) of Al2O3 oxides in the outer scale, (2) the presence of metastable oxide products of TiO and Nb2O5, (3) an amorphous region near the scale/substrate interface including the formation of AlNb2, and (4) O-Ti2AlNb phase oxidized to form Nb2O5, TiO2 and Al2O3.

A new cadinane sesquiterpenoid glucoside with cytotoxicity from Abelmoschus sagittifolius

A new cadinane sesquiterpenoid glucoside, 2β,7,3-trihydroxycalamenene 3-O-β-d-glucoside (1) together with six known compounds, N-(p-trans-coumaroyl)-N-methyl tyramine (2), Cleomiscosin A (3), 9,12,13-trihydroxy-10,15-heptadecadienoic acid (4), Cytochalasin B (5), Marmesinin (6) and N-(p-trans-coumaroyl) tyramine (7) were obtained from the stem bark of Abelmoschus sagittifolius. The new structure of compound 1 was elucidated by analysing its ¹H and ¹³C-NMR, ¹H-¹H COSY, HSQC, HMBC, NOESY and HR-ESI-MS spectra. Compounds 1-7 showed moderate cytotoxicity against Hela and HepG-2 human cancer cell lines.

Rational construction of an ssa-type of MOF through pre-organizing the ligand's conformation and its exceptional gas adsorption properties

A ligand conformation-controlled assembly strategy has been successfully employed to construct a copper-based MOF with the desired ssa-type topology, which exhibits exceptional C₂H₂ and CO₂ adsorption properties.

Adsorption and Diffusion of Fluids in Defective Carbon Nanotubes: Insights from Molecular Simulations

Single-walled carbon nanotubes (SWNTs) have been shown from both simulations and experiments to have remarkably low resistance to gas and liquid transport. This has been attributed to the remarkably smooth interior surface of pristine SWNTs. However, real SWNTs are known to have various defects that depend on the synthesis method and procedure used to activate the SWNTs. In this paper, we study adsorption and transport properties of atomic and molecular fluids in SWNTs having vacancy point defects. We construct models of defective nanotubes that have either unrelaxed defects, where the overall structure of the SWNT is not changed, or reconstructed defects, where the bonding topology and therefore the shape of the SWNT is allowed to change. Furthermore, we include partial atomic charges on the SWNT carbon atoms due to the reconstructed defects. We consider adsorption and diffusion of Ar atoms and CO₂ and H₂O molecules as examples of a noble gas, a linear quadrupolar fluid, and a polar fluid. Adsorption isotherms were found to be fairly insensitive to the defects, even for the case of water in the charged, reconstructed SWNT. We have computed both the self-diffusivities and corrected diffusivities (which are directly related to the transport diffusivities) for each of these fluids. In general, we found that at zero loading that defects can dramatically reduce the self- and corrected diffusivities. However, at high, liquidlike loadings, the self-diffusion coefficients for pristine and defective nanotubes are very similar, indicating that fluid-fluid collisions dominate the dynamics over the fluid-SWNT collisions. In contrast, the corrected diffusion coefficients can be more than an order of magnitude lower for water in defective SWNTs. This dramatic decrease in the transport diffusion is due to the formation of an ordered structure of water, which forms around a local defect site. It is therefore important to properly characterize the level and types of defects when accurate transport diffusivities are needed.

Mechanical properties of crossed-lamellar structures in biological shells: A review

The self-fabrication of materials in nature offers an alternate and powerful solution towards the grand challenge of designing advanced structural materials, where strength and toughness are always mutually exclusive. Crossed-lamellar structures are the most common microstructures in mollusks that are composed of aragonites and a small amount of organic materials. Such a distinctive composite structure has a fracture toughness being much higher than that of pure carbonate mineral. These structures exhibiting complex hierarchical microarchitectures that span several sub-level lamellae from microscale down to nanoscale, can be grouped into two types, i.e., platelet-like and fiber-like crossed-lamellar structures based on the shapes of basic building blocks. It has been demonstrated that these structures have a great potential to strengthen themselves during deformation. The observed underlying toughening mechanisms include microcracking, channel cracking, interlocking, uncracked-ligament bridging, aragonite fiber bridging, crack deflection and zig-zag, etc., which play vital roles in enhancing the fracture resistance of shells with the crossed-lamellar structures. The exploration and utilization of these important toughening mechanisms have attracted keen interests of materials scientists since they pave the way for the development of bio-inspired advanced composite materials for load-bearing structural applications. This article is aimed to review the characteristics of hierarchical structures and the mechanical properties of two kinds of crossed-lamellar structures, and further summarize the latest advances and biomimetic applications based on the unique crossed-lamellar structures.

CO2 adsorption of three isostructural metal-organic frameworks depending on the incorporated highly polarized heterocyclic moieties

A systematic investigation of CO2 adsorption behavior in three metal-organic frameworks was executed. The three MOFs adopted the same NbO-type structure, except that the organic ligands were grafted with different highly polarized heterocyclic moieties, namely, oxadiazole, thiadiazole, and selenadiazole, respectively. After activation, the three MOF materials, ZJNU-41a showed different surface areas and pore volumes depending on the incorporated heterocyclic rings attached to the organic ligands as well as the MOF's stabilities. Among the three MOF materials, exhibited an impressive CO2 uptake capacity of 97.4 cm(3) (STP) g(-1) at 298 K and 1 atm, which is comparable and even superior to those reported in NbO-type MOFs. In particular, when the molecular dipole of the attached heterocyclic moieties increases, the CO2 uptake also increases, which was further supported by comprehensive quantum chemical calculations. This work demonstrates that the introduction of highly polarized heterocyclic functional groups into frameworks is a promising approach to target porous metal-organic framework materials with improved CO2 adsorption performance.

An aminopyrimidine-functionalized cage-based metal–organic framework exhibiting highly selective adsorption of C2H2 and CO2 over CH4

An aminopyrimidine-functionalized cage-based metal–organic framework has been synthesized, which exhibited exceptionally high C₂H₂ and CO₂ uptake as well as impressive adsorption selectivities towards C₂H₂ and CO₂ over CH₄.

Phenotypic Characterization of Insulin-Resistant and Insulin-Sensitive Obesity

CONTEXT

Whereas insulin resistance and obesity coexist, some obese individuals remain insulin sensitive.

OBJECTIVE

We examined phenotypic and metabolic factors associated with insulin sensitivity in both muscle and liver in obese individuals.

DESIGN AND PARTICIPANTS

Sixty-four nondiabetic obese adults (29 males) underwent hyperinsulinemic (15 and 80 mU/m(2) · min)-euglycemic clamps with deuterated glucose. Top tertile subjects for glucose infusion rate during the high-dose insulin clamp were assigned Musclesen and those in the lower two tertiles were assigned Muscleres. Secondarily, top tertile subjects for endogenous glucose production suppression during the low-dose insulin clamp were deemed Liversen and the remainder Liverres.

MAIN OUTCOMES MEASURES

Clinical and laboratory parameters and visceral, subcutaneous, liver, and pancreatic fat were compared.

RESULTS

Musclesen and Muscleres had similar body mass index and total fat (P > .16), but Musclesen had lower glycated hemoglobin (P < .001) and systolic (P = .01) and diastolic (P = .03) blood pressure (BP). Despite similar sc fat (P = 1), Musclesen had lower visceral (P < .001) and liver (P < .001) fat. Liversen had lower visceral (P < .01) and liver (P < .01) fat and C-reactive protein (P = .02) than Liverres. When subjects were grouped by both glucose infusion rate during the high-dose insulin clamp and endogenous glucose production suppression, insulin sensitivity at either muscle or liver conferred apparent protection from the adverse metabolic features that characterized subjects insulin resistant at both sites. High-density lipoprotein-cholesterol, 1-hour glucose, systolic BP, and triglycerides explained 54% of the variance in muscle insulin sensitivity.

CONCLUSIONS

Obese subjects who were insulin sensitive at muscle and/or liver exhibited favorable metabolic features, including lower BP, liver and visceral adiposity. This study identifies factors associated with, and possibly contributing to, insulin sensitivity in obesity.

Halo current diagnostic system of experimental advanced superconducting tokamak

The design, calibration, and installation of disruption halo current sensors for the Experimental Advanced Superconducting Tokamak are described in this article. All the sensors are Rogowski coils that surround conducting structures, and all the signals are analog integrated. Coils with two different cross-section sizes have been fabricated, and their mutual inductances are calibrated. Sensors have been installed to measure halo currents in several different parts of both the upper divertor (tungsten) and lower divertor (graphite) at several toroidal locations. Initial measurements from disruptions show that the halo current diagnostics are working well.