Aromaticity in Fully π-Conjugated Multicyclic Macrocycles.

The research on aromaticity has mainly focused on monocyclic [n]annulene-like systems or polycyclic aromatic hydrocarbons. For fully π-conjugated multicyclic macrocycles (MMCs), the electronic coupling between the individual constitutional macrocycles would lead to unique electronic structures and aromaticity. The studies on MMCs, however, are quite limited, presumably due to the great challenges to design and synthesize a fully π-conjugated MMC molecule. Herein, we report the facile synthesis of two MMCs (2TMC and 3TMC) in which two and three thiophene-based macrocycles are fused together by employing both intramolecular and intermolecular Yamamoto coupling reactions of a properly designed precursor (7). The monocyclic macrocycle (1TMC) was also synthesized as a model compound. The geometry, aromaticity, and electronic properties of these macrocycles at different oxidation states were investigated by X-ray crystallographic analysis, NMR, and theoretical calculations, which disclosed how the constitutional macrocycles interplay with each other and lead to unique aromatic/antiaromatic character. This study provides new insights into the complex aromaticity in MMC systems.

Deep Learning With an Attention Mechanism for Differentiating the Origin of Brain Metastasis Using MR images.

BACKGROUND: Brain metastasis (BM) is a serious neurological complication of cancer of different origins. The value of deep learning (DL) to identify multiple types of primary origins remains unclear. PURPOSE: To distinguish primary site of BM and identify the best DL models. STUDY TYPE: Retrospective. POPULATION: A total of 449 BM derived from 214 patients (49.5% for female, mean age 58 years) (100 from small cell lung cancer [SCLC], 125 from non-small cell lung cancer [NSCLC], 116 from breast cancer [BC], and 108 from gastrointestinal cancer [GIC]) were included. FIELD STRENGTH/SEQUENCE: A 3-T, T1 turbo spin echo (T1-TSE), T2-TSE, T2FLAIR-TSE, DWI echo-planar imaging (DWI-EPI) and contrast-enhanced T1-TSE (CE T1-TSE). ASSESSMENT: Lesions were divided into training (n = 285, 153 patients), testing (n = 122, 93 patients), and independent testing cohorts (n = 42, 34 patients). Three-dimensional residual network (3D-ResNet), named 3D ResNet6 and 3D ResNet 18, was proposed for identifying the four origins based on single MRI and combined MRI (T1WI + T2-FLAIR + DWI, CE-T1WI + DWI, CE-T1WI + T2WI + DWI). DL model was used to distinguish lung cancer from non-lung cancer; then SCLC vs. NSCLC for lung cancer classification and BC vs. GIC for non-lung cancer classification was performed. A subjective visual analysis was implemented and compared with DL models. Gradient-weighted class activation mapping (Grad-CAM) was used to visualize the model by heatmaps. STATISTICAL TESTS: The area under the receiver operating characteristics curve (AUC) assess each classification performance. RESULTS: 3D ResNet18 with Grad-CAM and AIC showed better performance than 3DResNet6, 3DResNet18 and the radiologist for distinguishing lung cancer from non-lung cancer, SCLC from NSCLC, and BC from GIC. For single MRI sequence, T1WI, DWI, and CE-T1WI performed best for lung cancer vs. non-lung cancer, SCLC vs. NSCLC, and BC vs. GIC classifications. The AUC ranged from 0.675 to 0.876 and from 0.684 to 0.800 regarding the testing and independent testing datasets, respectively. For combined MRI sequences, the combination of CE-T1WI + T2WI + DWI performed better for BC vs. GIC (AUCs of 0.788 and 0.848 on testing and independent testing datasets, respectively), while the combined MRI approach (T1WI + T2-FLAIR + DWI, CE-T1WI + DWI) could not achieve higher AUCs for lung cancer vs. non-lung cancer, SCLC vs. NSCLC. Grad-CAM helped for model visualization by heatmaps that focused on tumor regions. DATA CONCLUSION: DL models may help to distinguish the origins of BM based on MRI data. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.

Efficacy of treatment based on TKIs in combination with PD-1 inhibitors for unresectable recurrent hepatocellular carcinoma.

BACKGROUND AND OBJECTIVE: The recurrence occurs within 5 years in up to 70% of hepatocellular carcinoma (HCC) patients who received radical liver resection, and most patients are no longer suitable for repeat surgery. There are limited treatment options for unresectable recurrent HCC. This study aimed to explore the potential efficacy of treatment based on TKIs in combination with PD-1 inhibitors for unresectable recurrent HCC. METHODS: Forty-four patients with unresectable recurrent HCC after radical surgery between January 2017 and November 2022 were retrospectively collected and screened. All patients received the combination therapy of tyrosine kinase inhibitors (TKIs) and programmed cell death protein 1 (PD-1) inhibitors, and 18 of these patients received trans-arterial chemoembolization (TACE) or TACE combined with radiofrequency ablation (RFA). Two patients who received TKIs in combination with PD-1 inhibitors eventually obtained repeat surgery, with one patient undergoing a repeat hepatectomy and one patient receiving a liver transplant. RESULTS: The median survival for these patients was 27.0 months (95% confidence interval [CI] 21.2, 32.8), with a 1-year overall survival (OS) rate of 83.6% (95% CI 77.9%, 89.3%). Median progression-free survival (PFS) was 15.0 months (95.0% CI 12.1, 17.9), with a 1-year PFS rate of 77.0% (95% CI 70.6%, 83.4%). The two patients who underwent repeat surgery had a survival time of 34 and 37 months after the combined treatment with no recurrence, respectively, as of November 2022. CONCLUSION: The combination of TKIs and PD-1 inhibitors for unresectable recurrent HCC is effective and can prolong the survival of patients in this group.

Long-term survival and portal vein patency with novel PVTT surgery approach in advanced HCC patients with Vp3/4 PVTT following combination therapy of TKIs and PD-1 inhibitors.

BACKGROUND: It is controversial whether patients with hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) should undergo salvage surgery following the combination therapy of tyrosine kinase inhibitors (TKIs) and programmed cell death protein 1 (PD-1) inhibitors. This study aimed to elucidate the efficiency and safety of salvage surgery following combination therapy, while also summarizing a novel surgical approach for Vp3/4 PVTT. METHODS: Between April 2019 and December 2022, a consecutive series of unresectable HCC patients with PVTT who received salvage surgery following combination therapy were enrolled. Evaluation included perioperative and long-term follow-up outcomes. The complete removal of Vp3/4 PVTT was achieved using a novel surgical approach characterized by "longitudinal incision and transverse suturing" and "angle-to-straight conversion". RESULTS: Forty patients including 22 patients with Vp3 and 18 patients with Vp4 were included. Long-term follow-up showed similar rates of portal vein patency (Vp3: 95.5%, Vp4:94.4%, p = 0.900), and 3-year portal vein patency rates were 95.0%. There were no significant differences observed in combination therapy-related adverse events (p = 0.253) and perioperative complications (p = 0.613) between the Vp3 and Vp4 groups. The recurrence patterns were similar between the two groups (p = 0.131). There were no significant differences in overall survival (OS) and recurrence-free (RFS) survival between the Vp3 and Vp4 groups (OS p = 0.457, RFS p = 0.985). Patients who achieved a pathological complete response had significantly better RFS (p = 0.011). CONCLUSION: Salvage surgery after combination therapy demonstrated favorable efficacy and safety. The novel surgical approach for PVTT can effectively achieve complete removal of PVTT and ensured long-term portal vein patency.

Self-Assembly of a Purely Organic Bowl in Water via Acylhydrazone Formation.

A bowl-shaped molecule can be self-assembled by condensing a triscationic hexaaldehyde compound and three equiv. of a dihydrazide linkers in pure water. The molecular bowl is thus composed of a triscationic π-electron deficient platform, as well as a hexagonal rim that contains six acylhydrazone functions. When the counteranions are chloride, the solid-state structure reveals that this molecular bowl undergoes dimerization via N-H···Cl hydrogen bonds, forming a cage-like dimer with a huge inner cavity. This molecular bowl can employ its cavity to accommodate a hydrophobic guest, namely 1-adamantanecarboxylic acid in aqueous media.

Comparison of survival benefit between salvage surgery after conversion therapy versus surgery alone for hepatocellular carcinoma with portal vein tumor thrombosis: a propensity score analysis.

BACKGROUND: Salvage surgery after conversion therapy with a combination of tyrosine kinase inhibitor and anti-programmed death-1 antibody has shown improved survival benefits in patients with hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT). We aimed to compare the survival benefits in a retrospective cohort of patients with HCC with PVTT who underwent salvage surgery after conversion therapy and surgery alone. METHODS: From January 2015 to October 2021, we selected patients diagnosed with HCC with PVTT who underwent liver resection at Chinese PLA General Hospital. The primary endpoint in the comparison of survival benefits between conversion therapy and surgery-alone groups was recurrence-free survival. Propensity score matching was applied to reduce any potential bias in the study. RESULTS: The 6-, 12-, and 24-month recurrence-free survival rates in the conversion and surgery alone groups were 80.3% vs 36.5%, 65.4% vs 29.4%, and 56% vs 21%, respectively. On multivariable Cox regression analyses, conversion therapy significantly reduced HCC-related mortality and HCC recurrence rates compared with surgery alone. CONCLUSIONS: For patients with HCC with PVTT, surgery after conversion therapy is in relationship with increased survival in comparison with surgery alone.

Facile Synthesis of a Fully Fused, Three-Dimensional π-Conjugated Archimedean Cage with Magnetically Shielded Cavity.

The synthesis of molecular cages consisting of fully fused, π-conjugated rings is rare due to synthetic challenges including preorganization, large strain, and poor solubility. Herein, we report such an example in which a tris-2-aminobenzophenone precursor undergoes acid-mediated self-condensation to form a truncated tetrahedron, one of the 13 Archimedean solids. Formation of eight-membered [1,5]diazocine rings provides preorganization and releases the strain while still maintains weak π-conjugation of the backbone. Thorough characterizations were performed by X-ray, NMR, and UV-vis analysis, assisted by theoretical calculations. The cage exhibits a rigid backbone structure with a well-defined cavity that confines a magnetically shielded environment. The solvent molecule, o-dichlorobenzene, is precisely encapsulated in the cavity at a 1:1 ratio with multiple π···π, C-H···π, and halogen···π interactions with the cage skeleton, implying its template effect for the cage closing reaction. Our synthetic strategy opens the opportunity to access more complex, fully fused, three-dimensional π-conjugated cages.

A Self-Assembled Homochiral Radical Cage with Paramagnetic Behaviors.

Condensation of an inherently C3 -symmetric polychlorotriphenylmethyl (PTM) radical trisaldehyde with tris(2-aminoethyl)amine (TREN) yields a [4+4] tetrahedral radical cage as a racemic pair of homochiral enantiomers in 75 % isolated yield. The structure was characterized by X-ray crystallography, confirming the homochirality of each cage framework. The homochirality results from intramolecular [CH⋅⋅⋅π] and hydrogen-bonding interactions within the cage framework. The four PTM radicals in a cage undergo weak through-space coupling. Magnetic measurements demonstrated that each cage bears 3.58 spins.

Self-Assembly of a Purely Covalent Cage with Homochirality by Imine Formation in Water.

Self-assembly of host molecules in aqueous media via metal-ligand coordination is well developed. However, the preparation of purely covalent counterparts in water has remained a formidable task. An anionic tetrahedron cage was successfully self-assembled in a [4+4] manner by condensing a trisamine and a trisformyl in water. Even although each individual imine bond is rather labile and apt to hydrolyze in water, the tetrahedron is remarkably stable or inert due to multivalence. The tetrahedral cages, as well as its neutral counterparts dissolved in organic solvent, have homochirality, namely that their four propeller-shaped trisformyl residues adopt the same rotational conformation. The cage is able to take advantage of hydrophobic effect to accommodate a variety of guest molecules in water. When a chiral guest was recognized, the formation of one enantiomer of the cage became more favored relative to the other. As a consequence, the cage could be produced in an enantioselective manner. The tetrahedron is able to maintain its chirality after removal of the chiral guest-probably on account of the cooperative occurrence of intramolecular forces that restrict the intramolecular flipping of phenyl units in the cage framework.

Self-Assembly in Water with N-Substituted Imines.

Imine synthesis has enjoyed a long history as the dynamic covalent reaction of choice for the construction of purely covalent molecular architectures. In organic solvents, the formation of imine bonds is reversible but leads to thermodynamically stable products. In the presence of water, however, imine bonds are labile, a fact which limits their utility as mediators of self-assembly in aqueous and biological media. In this Review, we discuss water-compatible dynamic covalent bonds based on N-substituted imine derivatives, namely hydrazones and oximes, for the self-assembly of metal-free organic architectures with well-defined structures. The reasons why hydrazones and oximes are more robust in water than their parent imines are explained. Recent progress in the self-assembly, characterization, and design principles of a variety of complex molecules including macrocycles, cages, catenanes, and knots in aqueous media is highlighted. Emerging applications for these molecules, including guest recognition and separations, are also discussed.

Stabilizing the Naphthalenediimide Radical within a Tetracationic Cyclophane.

Organic radicals are of importance in developing smart materials that have paramagnetic and/or near-infrared optical properties. Their practical applications, however, are limited by the labile nature of the radicals. Here, we demonstrate that by using a tetracationic cyclophane, namely, cyclobis(4,4'-(1,4-phenylene)bispyridine-p-phenylene) (ExBox4+), to encapsulate a naphthalenediimide (NDI) guest, the redox properties of NDI can be modulated. In organic solvents such as MeCN or DMF, ExBox4+ is able to provide the surrounding Coulombic attraction to the NDI•- radical anion and therefore enhance its stability toward oxidation. In water, NDI•- is prone to dimerization, forming its (NDI•-)2 dimer. Under UV-light irradiation, the (NDI•-)2 dimer is observed to disproportionate and yield the dianionic NDI2-. ExBox4+ is able to encapsulate the NDI•- radical anion and prevent its dimerization, and as a consequence, the radical anion is protected from further reduction in a noncovalent manner. We believe that our strategy of modulating the redox properties of NDI by either host-guest recognition or mechanical interlocking can aid and abet the development of radical-based materials, which could be employed in pursuit of applications in many areas, such as transporting spin and charges.

Controllable Self-Assembly of Macrocycles in Water for Isolating Aromatic Hydrocarbon Isomers.

A series of purely organic macrocycles and catenanes can be self-assembled by condensing a cationic bisaldehyde compound with a series of dihydrazide linkers in weakly acidic water. On one hand, the macrocycles could be generated as the predominant products under the condition of low concentration or less polar media. In the presence of a guest template, these macrocycles could even be obtained in close to quantitative yields, allowing them to be isolated as pure solid products without the need for chromatographic purification. On the other hand, [2]catenanes could be obtained as the major products in more concentrated solutions or more polar media where hydrophobic effects are enhanced. Once purified, both macrocycles and catenanes exhibit remarkable kinetic stability in both the solid state and neutral aqueous solution at room temperature. By means of selective host-guest recognition, one of the macrocyclic products is capable of resolving a pair of hydrocarbon isomers, namely phenanthrene and anthracene, which have similar properties and can hardly be separated by commonly used approaches.

Precursor Control over the Self-Assembly of Organic Cages via Imine Condensation.

A series of tetrahedral cages and triangular prisms have been self-assembled by condensing ostensibly analogous trisformyl precursors with tris or bisamino linkers under the nominally reversible reaction conditions in the manner of either [4 + 4] or [2 + 3], respectively. We observed that the conformations of the trisformyl precursors have great impact on the self-assembly pathway and product yields. More specifically, a rigid and planar precursor favors the formation of prisms while a more twisted one favors tetrahedron. As a comparison, a more flexible precursor, which is able to adopt both relatively planar and twisted conformations, is capable of producing both prisms and tetrahedrons in relatively high yields. Both experimental and theoretical results indicate that the self-assembly preference is ascribed to subtle variations in the level of π-π and CH-π interactions that act as the driving forces for the formation of prisms and tetrahedrons, respectively.

Dynamic Covalent Self-Assembly Based on Oxime Condensation.

Oxime, whose dynamic nature was reported to be switchable between ON/OFF by tuning the acidity, is employed in a novel type of dynamic covalent approach that is amenable to use in water for self-assembly of purely organic molecules with complex topology. In strongly acidic conditions, the dynamic nature of oxime is turned ON, allowing occurrence of error-checking and therefore a catenane and a macrocycle self-assembled in high yields. In neutral conditions, oxime ceases to be dynamic, which helps to trap the self-assembled products even when the driving forces of their formation are removed. We envision that this switchable behaviour might help, at least partially, to resolve a commonly encountered drawback of dynamic covalent chemistry, namely that the intrinsic stability of the self-assembled products containing dynamic bonds, such as imine or hydrazone, are often jeopardized by their reversible nature.

Trapping White Phosphorus within a Purely Organic Molecular Container Produced by Imine Condensation.

Three tetrahedral organic cages have been obtained by condensing a triamino linker with a set of three ostensibly analogous triformyl precursors. Despite the large number of imine bonds formed, the corresponding cages were obtained in exceptionally high yields. Both theory and experimental results demonstrate that intramolecular CH⋅⋅⋅π interactions within all of the cage frameworks play an important role in abetting the condensations and contributing to the near-quantitative synthetic yields. The three cages of this study exhibit high thermodynamic and kinetic stability. A variety of small neutral guest molecules with complementary sizes and geometries may be used as templates in the cage forming reactions. Among the guests that may be used in this way is white phosphorus (P4 ), whose inherent reactivity towards oxygen is almost fully attenuated when bound within one of the cages.

A Two-Step Synthetic Strategy toward Monodisperse Colloidal CdSe and CdSe/CdS Core/Shell Nanocrystals.

CdSe magic-size clusters with close-shell surface and fixed molecular formula are well-known in the size range between ∼1 and 3 nm. By applying high concentration of cadmium alkanoates as ligands, a conventional synthetic system for CdSe nanocrystals was tuned to discriminate completion from initiation of atomic flat facets. This resulted in ∼4-13 nm CdSe nanocrystals with hexahedral shape terminated with low-index facets, namely three (100), one (110), and two (111) facets. These low-symmetry (Cs group with single mirror plane) yet monodisperse hexahedra were found to be persistent not only in a broad size range but also under typical synthetic temperatures for growth of both CdSe and CdS. Atomic motion on the surface of the nanocrystals under enhanced ligand dynamics initiated intraparticle ripening without activating interparticle ripening, which converted the hexahedral nanocrystals to monodisperse spherical ones. This new synthetic strategy rendered optimal color purity of photoluminescence (PL) of the CdSe and CdSe/CdS core/shell nanocrystals, with the ensemble PL peak width comparable with that of a corresponding single dot.

Characterization of prostatic cancer lesion and gleason grade using a continuous-time random-walk diffusion model at high b-values.

Background: Distinguishing between prostatic cancer (PCa) and chronic prostatitis (CP) is sometimes challenging, and Gleason grading is strongly associated with prognosis in PCa. The continuous-time random-walk diffusion (CTRW) model has shown potential in distinguishing between PCa and CP as well as predicting Gleason grading. Purpose: This study aimed to quantify the CTRW parameters (α, ß & Dm) and apparent diffusion coefficient (ADC) of PCa and CP tissues; and then assess the diagnostic value of CTRW and ADC parameters in differentiating CP from PCa and low-grade PCa from high-grade PCa lesions. Study type: Retrospective (retrospective analysis using prospective designed data). Population: Thirty-one PCa patients undergoing prostatectomy (mean age 74 years, range 64-91 years), and thirty CP patients undergoing prostate needle biopsies (mean age 68 years, range 46-79 years). Field strength/Sequence: MRI scans on a 3.0T scanner (uMR790, United Imaging Healthcare, Shanghai, China). DWI were acquired with 12 b-values (0, 50, 100, 150, 200, 500, 800, 1200, 1500, 2000, 2500, 3000 s/mm2). Assessment: CTRW parameters and ADC were quantified in PCa and CP lesions. Statistical tests: The Mann-Whitney U test was used to evaluate the differences in CTRW parameters and ADC between PCa and CP, high-grade PCa, and low-grade PCa. Spearman's correlation of the pathologic grading group (GG) with CTRW parameters and ADC was evaluated. The usefulness of CTRW parameters, ADC, and their combinations (Dm, α and ß; Dm, α, ß, and ADC) to differentiate PCa from CP and high-grade PCa from low-grade PCa was determined by logistic regression and receiver operating characteristic curve (ROC) analysis. Delong test was used to compare the differences among AUCs. Results: Significant differences were found for the CTRW parameters (α, Dm) between CP and PCa (all P<0.001), high-grade PCa, and low-grade PCa (α:P=0.024, Dm:P=0.021). GG is correlated with certain CTRW parameters and ADC(α:P<0.001,r=-0.795; Dm:P<0.001,r=-0.762;ADC:P<0.001,r=-0.790). Moreover, CTRW parameters (α, ß, Dm) combined with ADC showed the best diagnostic efficacy for distinguishing between PCa and CP as well as predicting Gleason grading. The differences among AUCs of ADC, CTRW parameters and their combinations were not statistically significant (P=0.051-0.526). Conclusion: CTRW parameters α and Dm, as well as their combination were beneficial to distinguish between CA and PCa, low-grade PCa and high-grade PCa lesions, and CTRW parameters and ADC had comparable diagnostic performance.

Differentiation of Lung Metastases Originated From Different Primary Tumors Using Radiomics Features Based on CT Imaging.

RATIONALE AND OBJECTIVES: To explore the feasibility of differentiating three predominant metastatic tumor types using lung computed tomography (CT) radiomics features based on supervised machine learning. MATERIALS AND METHODS: This retrospective analysis included 252 lung metastases (LM) (from 78 patients), which were divided into the training (n = 176) and test (n = 76) cohort randomly. The metastases originated from colorectal cancer (n = 97), breast cancer (n = 87), and renal carcinoma (n = 68). An additional 77 LM (from 35 patients) were used for external validation. All radiomics features were extracted from lung CT using an open-source software called 3D slicer. The least absolute shrinkage and selection operator (LASSO) method selected the optimal radiomics features to build the model. Random forest and support vector machine (SVM) were selected to build three-class and two-class models. The performance of the classification model was evaluated with the area under the receiver operating characteristic curve (AUC) by two strategies: one-versus-rest and one-versus-one. RESULTS: Eight hundred and fifty-one quantitative radiomics features were extracted from lung CT. By LASSO, 23 optimal features were extracted in three-class, and 25, 29, and 35 features in two-class for differentiating every two of three LM (colorectal cancer vs. renal carcinoma, colorectal cancer vs. breast cancer, and breast cancer vs. renal carcinoma, respectively). The AUCs of the three-class model were 0.83 for colorectal cancer, 0.79 for breast cancer, and 0.91 for renal carcinoma in the test cohort. In the external validation cohort, the AUCs were 0.77, 0.83, and 0.81, respectively. Swarmplot shows the distribution of radiomics features among three different LM types. In the two-class model, high accuracy and AUC were obtained by SVM. The AUC of discriminating colorectal cancer LM from renal carcinoma LM was 0.84, and breast cancer LM from colorectal cancer LM and renal carcinoma LM were 0.80 and 0.94, respectively. The AUCs were 0.77, 0.78, and 0.84 in the external validation cohort. CONCLUSION: Quantitative radiomics features based on Lung CT exhibited good discriminative performance in LM of primary colorectal cancer, breast cancer, and renal carcinoma.

Factors influencing the prognosis patients with Barcelona Clinic Liver Cancer stage C hepatocellular carcinoma undergoing salvage surgery after conversion therapy.

Background: The aim of this study was to investigate the prognostic factors influencing the outcome of patients with Barcelona Clinic Liver Cancer stage C hepatocellular carcinoma (HCC) receiving salvage surgery after conversion therapy based on tyrosine kinase inhibitors (TKIs) and anti-programmed death-1 (PD-1) antibodies. Methods: From June 2018 to December 2022, patients receiving salvage surgery after conversion therapy based on PD-1 and TKIs at the Faculty of Hepato-Pancreato-Biliary Surgery, Chinese PLA General Hospital were retrospectively recruited for this study. Overall survival (OS) and recurrence-free survival (RFS) were observed as the primary end point in the Cox analysis of prognostic factors among this study. Results: The 6- and 12-month RFS rates were 77.0% and 64.8%, respectively, while the 6-, 12-, 24-, and 36-month OS rates were 98.4%, 93.4%, 76.8%, and 69.8%, respectively. The median OS and RFS were not reached. On multivariable Cox regression analyses, low serum alpha fetoprotein (AFP) level (≤20 ng/mL) after conversion therapy [hazard ratio (HR) 0.186, 95% CI: 0.039-0.887; P=0.035) and microvascular invasion (MVI) grade II (HR 3.054, 95% CI: 1.000-9.329; P=0.050) were independent factors associated with a higher OS and RFS. Conclusions: For patients with Barcelona Clinic Liver Cancer stage C (BCLC-C) HCC, lower AFP level after conversion therapy (<20 ng/mL) and MVI II were associated with a higher OS and lower RFS rate, respectively.

The sharp structural switch of covalent cages mediated by subtle variation of directing groups.

It is considered a more formidable task to precisely control the self-assembled products containing purely covalent components, due to a lack of intrinsic templates such as transition metals to suppress entropy loss during self-assembly. Here, we attempt to tackle this challenge by using directing groups. That is, the self-assembly products of condensing a 1:2 mixture of a tetraformyl and a biamine can be precisely controlled by slightly changing the substituent groups in the aldehyde precursor. This is because different directing groups provide hydrogen bonds with different modes to the adjacent imine units, so that the building blocks are endowed with totally different conformations. Each conformation favors the formation of a specific product that is thus produced selectively, including chiral and achiral cages. These results of using a specific directing group to favor a target product pave the way for accomplishing atom economy in synthesizing purely covalent molecules without relying on toxic transition metal templates.