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Variable stoichiometry co-crystals are important in solid-state supramolecular chemistry as they allow studies of structure-property relationships while permitting the synthesis of new scaffolds using identical synthons. In this work, we extend the concept of variable stoichiometry co-crystals into the realm of pillararene chemistry and show that this permits the rational construction of a diverse set of supramolecular structures in the solid state. Specifically, we report a series of variable stoichiometry co-crystals based on pillar[

The modernized private tutoring in China appeared in the 1990s and then grew at full speed to become one of the world’s most extensive shadow education systems. Since 2010, the industry has entered an era of deepening institutionalization and capitalization. This paper, through the narrative of an expert tutor, illuminates his experiences of tutoring and managing in this industry from 2010 to 2020 in Mainland China. The narrative was constructed through the tutor’s chronological reflection, which was stimulated by various electronic files he produced during the tutoring period and his ongoing conversations with former colleagues. In making sense of his narrative, the researchers have discussed a neglected phenomenon, three shining points, six gray areas, and four developmental stages of shadow education to demonstrate the industry features and evolution. Through discussing these issues, this paper finds its originality in illustrating at a micro level the industry’s operational mechanism, such as tutor training, curriculum, instruction, and after-class management, from a unique perspective of a tutoring practitioner and entrepreneur.

The transformations of CO2 molecules into valuable products are of increasing interest due to the negative impact of anthropogenic CO2 emissions on global warming. The CO2-to-methanol hydrogenation is an economically profitable reaction of carbon fixation, but it still steps away from widespread industrialization because of the lack of efficient and selective catalysts. Recently, single-atom alloy (SAA) catalysts have been developed to work remarkably in CO2 hydrogenation reactions. Doping isolated single atoms into metallic catalyst can dramatically alter the catalytic performance of the host. We have performed a screening discovery on Ru and 6 RuX (X = Fe, Co, Ni, Cu, Ir and Pt) SAAs using density functional theory (DFT) computations. We considered 13 possible elementary reactions in 4 possible reaction pathways on Ru and all RuX surfaces. In the computed mechanisms, we found that the formation of *H2COOH and *HCOO intermediates plays a critical role in determining catalysts’ activities. Doping Co and Pt isolated single atoms into Ru surface can thermodynamically and kinetically facilitate these intermediates formation processes, eventually promoting the production of methanol. The combination of weak binding and enhanced charge redistribution on RuCo and RuPt surfaces give them improved catalytic activities over pure Ru. This work will ultimately facilitate the discovery and development of SAAs for CO2 to methanol, serving as guidance to experiments and theoreticians alike.

Supramolecular polymers, generated by connecting monomers through noncovalent interactions, have received considerable attention over the past years, as they provide versatile platforms for developing diverse aesthetically pleasing polymeric structures with promising applications in a variety of fields, such as medicine, catalysis, and sensing. In the development of supramolecular polymers, macrocyclic hosts play a very important role. Benefiting from their abundant host-guest chemistry and self-assembly characteristics, macrocycles themselves or their host-guest complexes can self-assemble to form well-ordered supramolecular polymeric architectures including pseudopolyrotaxanes and polyrotaxanes. The integration of these topological structures into supramolecular polymeric materials also imbues them with some unforeseen functions. Current interest in macrocycle-based supramolecular polymers is mostly focused on the development of supramolecular soft materials in solution or gel-state, in which the dynamic nature of noncovalent interactions endows supramolecular polymers with a wealth of "smart" properties, such as multiresponsiveness and self-repair capabilities. While preparation of macrocycle-derived supramolecular polymers in the solid state is a relatively challenging but intriguing prospect, they are an important part of the field of supramolecular polymers. On one hand, the construction of macrocycle-based solid-state supramolecular polymers enables us to obtain new materials with novel properties and functions such as mechano-responsiveness. On the other hand, the molecular structures and arrangements in these materials are well-identified by X-ray crystallography techniques, offering a direct visual representation of the supramolecular polymerization process. The analysis of the role of noncovalent interactions in these architectures allows us to design more sophisticated and elegant supramolecular polymers in a highly rationalized and controllable manner. This Account serves to summarize the research progress on macrocycle-based solid-state supramolecular polymers (MSSPs), including the contributions toward this field made by our group. For constructing MSSPs, the key point is to control noncovalent interactions. Thus, in this Account, we primarily classify these MSSPs by different noncovalent interactions involved to connect the monomers, including metal-ligand interactions, host-guest interactions, π···π stacking, and halogen bonding. These noncovalent interactions are highly associated with the structures and functions of the resultant MSSPs. For instance, using metal-ligand interactions as driving forces, metal clusters can be introduced in MSSPs which afford systems with solid-state luminescence or proton conduction properties; supramolecular polymerization using macrocycle-based host-guest interactions can modulate the molecular arrangement of some specific molecules in the solid state, which further influences their solid-state properties; π···π stacking interactions and halogen bonding give chemists more choice to design MSSPs with various elements. The role of macrocyclic hosts in MSSPs is also revealed in these descriptions. Finally, the remaining challenges are identified for further development of future prospects. We hope that this Account can inspire new discoveries in the realm of supramolecular functional systems and offer new opportunities for the construction of supramolecular architectures and solid-state materials.

Bone scaffolds require both good bioactivity and mechanical properties to keep shape and promote bone repair. In this work, T-ZnOw enhanced biphasic calcium phosphate (BCP) scaffolds with triply periodic minimal surface (TPMS)-based double-layer porous structure were fabricated by digital light processing (DLP) with high precision. Property of suspension was first discussed to obtain better printing quality. After sintering, T-ZnOw reacts with β-tricalcium phosphate (β-TCP) to form Ca19Zn2(PO4)14, and inhibits the phase transition to α-TCP. With the content of T-ZnOw increasing from 0 to 2 wt%, the flexural strength increases from 40.9 to 68.5 MPa because the four-needle whiskers can disperse stress, and have the effect of pulling out as well as fracture toughening. However, excessive whiskers will reduce the cure depth, and cause more printing defects, thus reducing the mechanical strength. Besides, T-ZnOw accelerates the deposition of apatite, and the sample with 2 wt% T-ZnOw shows the fastest mineralization rate. The good biocompatibility has been proved by cell proliferation test. Results confirmed that doping T-ZnOw can improve the mechanical strength of BCP scaffolds, and keep good biological property, which provides a new strategy for better bone repair.

Control of toxic or carcinogenic disinfection byproduct (DBP) formation in drinking water is critical in an effort to improve drinking water safety and safeguard public health, due to the elevation...

In recent years, amorphous bioglass is used to improve the bioactivity of HA (Ca10(PO4)6(OH)2). Nevertheless, bioglass crystallizes and reacts with the matrix to form a complex phase composition during sintering, resulting in an unclear mechanism for tailoring the properties of HA bioceramics. In this work, TPMS structural HA ceramics fabricated by digital light processing (DLP) were doped by akermanite (Ca2MgSi2O7) to better tailor the porosity, bioactivity and mechanical strength. After sintering above 1000 °C, Mg2+ ions from akermanite substitute Ca2+ ions in HA, leading to the decomposition of HA into β-TCP. This process increases the porosity of bioceramics. Additionally, liquid phases sintering caused by akermanite gives rise to the densification and enhancement of grain bonding, thereby reinforcing the mechanical strength of scaffolds. For in vitro bioactivity, as the content of akermanite increases from 0 wt.% to 20 wt.%, carbonated hydroxyapatite firstly deposits onto the surfaces of scaffolds and then disappears, because excessive Mg2+ prevent the hydroxyapatite crystallization. Finally, bioceramics with 5 wt.% and 10 wt.% of akermanite and sintering at 1100 °C exhibit a high porosity of over 80% and an appropriate compressive strength of over 2 MPa, while achieving an enhanced in vitro bioactivity and good biocompatibility. After optimization, this kind of porous scaffolds can be well applied to the repair of cancellous bone defect.

Yao Li,1,* Xin Yang,1,* Jie Sun,2 Yangyang Zhao,3 Qi Zhou,3 Bin Hua1 1Breast Center, Department of Thyroid-Breast-Hernia Surgery, Department of General Surgery, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, People’s Republic of China; 2Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People’s Republic of China; 3The Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, People’s Republic of China*These authors contributed equally to this workCorrespondence: Bin HuaBreast Center, Department of Thyroid-breast-hernia Surgery, Department of General Surgery, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, People’s Republic of ChinaTel +86-10-85136127Fax +86-10-65132969Email huabinbjh@126.comPurpose: Invasive breast carcinoma (BC) is the most common malignant breast tumor. Most lymph node-negative (LN−) early-stage BC patients usually have a good prognosis, but 7% of patients still develop metastasis after surgery. It is not yet clear how to screen candidates with poorer prognosis in LN− early-stage patients, so that they can receive intensive therapy. Hence, we expect to identify a prognostic biomarker to assess postoperative metastasis in LN− early-stage BC patients.Patients and Methods: Screening and verifying of candidate genes by gene expression profiling of LN− early-stage BC samples (n = 640) from 3 independent public datasets. Univariable and multivariable Cox regression analyses showed the relation between the candidate genes and postoperative metastasis. Distant metastasis-free survival (DMFS) analysis was performed to examine the prognostic significance. Quantitative real-time polymerase chain reaction (qRT-PCR) assays were performed to examine ADAMTS8 expression and prognostic association in our clinical samples (n = 25).Results: In the discovery cohort (TCGA and GSE20685 datasets), we found that ADAMTS8 tend to be low expression in LN− early-stage BC, and low ADAMTS8 expression was associated with postoperative metastasis and shortened DMFS. Moreover, the above finding was confirmed in the validation cohort (GSE6538 dataset). Lower ADAMTS8 expression was related to poorer prognostic clinical stage and PAM50 subtypes and shorter DMFS. Gene enrichment analysis indicated that ADAMTS8 may be correlated with BC metastasis. qRT-PCR assays of our clinical tumor sample showed that patients with low ADAMTS8 expression seem to be prone to developing metastasis and have a shorter DMFS time.Conclusion: Our research shows that low ADAMTS8 expression is associated with postoperative metastasis and shortened DMFS in LN− early-stage BC patients, which suggests that ADAMTS8 may be a potential prognostic marker for postoperative metastasis in LN− early-stage BC patients.Keywords: ADAMTS8, lymph node-negative early-stage invasive breast carcinoma, distant metastasis-free survival, biomarker

Objective To detect the extracellular hydrogen ion (H+) flux of breast cancer tissue explants using noninvasive microtest technology (NMT) and assess how this flux correlates with the molecular subtype. Further more, we preliminarily explored the possibility of applying NMT as a treatment prescreening tool for predicting how docetaxel will affect tissue responses. Methods This study enrolled 30 breast cancer patients who underwent surgery in the Department of Breast Surgery at Beijing Hospital, Beijing, China. Tumor samples and the corresponding normal samples were excised from surgical specimens with a size of approximately 0.5 cm3. The NMT system was used to detect the H+ flux of tumor samples and corresponding normal samples. Then, the NMT system was used to assess the changes in H + flux after the tumor samples were treated with 10 mg/L docetaxel. Results All the samples produced stable H + flux that could be measured in real time. In 26 cases, we found that tumor samples exhibited stable and robust efflux of H+, whereas in the corresponding normal samples, we measured significant differences with H+ influx or mild efflux (cancer samples: 0.336 ± 0.307 pmol/cm− 2/sec− 1 vs. normal samples: -0.067 ± 0.131, p +, there were 4 luminal A type, 11 luminal B type, 6 HER2-positive type and 5 triple-negative type. Triple-negative tumors had a higher rate of H + efflux compared with luminal A, luminal B and HER2 positive tumors (p = 0.016, p = 0.018, p = 0.008). Among the 4 tumor samples that were treated with docetaxel, 3 samples showed inhibition of H + efflux by 50.5%, 28.8% and 8.3%, while efflux increased by 30.0% in 1 sample. Conclusion NMT can detect the H + flux of breast cancer tissue in real time. The H + flux of tumor samples was significantly different from that of normal samples. After treatment with docetaxel, the H + flux of tumor samples showed definite changes.

Background:More than half of Chinese patients with hormone receptor positive (HR+) ductal carcinoma in situ (DCIS) are treated with mastectomy, and usually subjected to postoperative endocrine therapy (ET). Given that long-term ET can cause severe adverse effects it is important to determine the beneficial effect and safety of post-mastectomy ET on the disease-free survival (DFS) and adverse events in patients with HR+ DCIS.Methods:To explore beneficial effect and safety of post-mastectomy ET in patients with HR+ DCIS, we performed a multicenter, population-based study. This retrospective study analyzed the DFS and adverse events in 1037 HR+ DCIS Chinese patients with or without post-mastectomy ET from eight breast centers between 2006 and 2016. The median follow-up time period was 86 months.Results:There were 791 DCIS patients receiving ET (ET group). Those patients were followed up for a median of 86 months (range, 60–177 months). There were 23 cases with tumor recurrence or distant metastasis. There were similar 5-year DFS rates and DFS between the ET and non-ET groups, even for those with high-risk factors. Conversely, 37.04% of patients suffered from adverse events after ET, which were significantly higher than those in the non-ET group.Conclusions:ET after mastectomy did not benefit patients with HR+ DCIS for their DFS, rather increased adverse events in those patients. Therefore, ET after mastectomy may not be recommended for patients with HR+ DCIS, even for those with high-risk factors, such as multifocal, microinvasive, and higher T stage.Funding:This study was supported by grants from Outstanding Scientific Fund of Shengjing Hospital (201803) and Outstanding Young Scholars of Liaoning Province (2019-YQ-10).

Liposomes and polymersomes, typical vesicular drug delivery systems (DDSs), have faced some limitations in cancer theranostics. Suprasomes, supramolecular vesicles assembled from amphiphiles linked by noncovalent interactions, show potential as new generation of vesicular DDSs. We construct suprasomes based on host-guest recognition, by which the desired functions can be integrated into carriers without tedious synthesis. Photothermally active host-guest complex is formed between a functional guest and pillar[5]arene, which further self-assembles into hollow suprasomes. A supramolecular nanomedicine is developed by encapsulating cisplatin in the suprasomes. The obtained cisplatin@Suprasomes achieve excellent anticancer efficacy and anti-metastasis combining chemotherapy and photothermal therapy, which ablate the tumors without relapse and metastasis. This work demonstrates the facile functionalization of suprasomes, holding promise as alternatives to liposomes and polymersomes.

Silica ceramic cores have played an important part in the manufacture of hollow blades due to their excellent chemical stability and moderate high-temperature mechanical properties. In this study, silica-based ceramics were prepared with Al2O3 addition by stereolithography, and the influence of Al2O3 content on mechanical properties of the silica-based ceramics was investigated. The Al2O3 in silica-based ceramics can improve the mechanical properties by playing a role as a seed for the crystallization of fused silica into cristobalite. As a result, with the increase of Al2O3 content, the linear shrinkage of the silica-based ceramics first decreased and then increased, while the room-temperature flexural strength and the high-temperature flexural strength first increased and then decreased. As the Al2O3 content increased to 1.0 vol%, the linear shrinkage was reduced to 1.64% because of the blocked viscous flow caused by Al2O3. Meanwhile, the room-temperature flexural strength and the high-temperature flexural strength were improved to 20.38 and 21.43 MPa with 1.0 vol% Al2O3, respectively, due to the increased α-cristobalite and β-cristobalite content. Therefore, using the optimal content of Al2O3 in silica-based ceramics can provide excellent mechanical properties, which are suitable for the application of ceramic cores in the manufacturing of hollow blades.

Background Low human epidermal growth factor receptor 2 (HER2) expression is an emerging concept in breast cancer that is defined as immunohistochemistry (IHC) 1 + or IHC 2 + and negative in situ hybridization (ISH) but has been poorly investigated. The aim of our study was to determine the frequency of low HER2 expression among HER2-negative breast cancers and compare the clinicopathological features and prognosis of HER2-low patients with those of HER2-zero patients. Methods We collected the data of 684 patients with primary HER2-negative breast cancer who underwent surgery between January 2012 and September 2021 from our self-built database. Clinicopathological features, recurrence-free interval (RFI) and breast cancer-specific survival (BCSS) were compared between HER2-low and HER2-zero (IHC 0) patients. Results Among the 684 patients, 512 (74.9%) patients had low HER2 expression, and 172 (25.1%) patients had zero HER2 expression. The average age was 57.7 ± 12.6 years, 472 (69.0%) patients were aged P P P = 0.028) and P = 0.000). Multivariate Cox regression analysis showed that low HER2 expression was a low-risk factor for RFI (HR: 0.531, 95% CI: 0.292–0.967, P = 0.038) but had no influence on BCSS (P = 0.272). Conclusions HER2-low tumors had a higher proportion of HR positivity and a lower rate of histological grade III than HER2-zero tumors. Low HER2 expression seemed to be a protective factor for RFI, especially in patients with HR + and those younger than 65 years.

BackgroundMore than half of Chinese patients with hormone receptor positive (HR+) ductal carcinoma in situ (DCIS) are treated with mastectomy, and usually followed by endocrine therapy (ET). Given that long-term ET can cause severe adverse effects it is important to determine the beneficial effect and safety of adjuvant ET after mastectomy on the disease-free survival (DFS) and adverse events in patients with HR+ DCIS.MethodsTo explore beneficial effect and safety of ET after mastectomy in patients with HR+ DCIS, we performed a multicenter, population-based study. This retrospective study analyzed the DFS and adverse events in 1037 HR+ DCIS Chinese patients with or without post-mastectomy ET from eight Breast Centers between 2006-2016. The median follow-up time was 86 months.ResultsThere were 791 DCIS patients receiving ET (ET group). Those patients were followed-up for a median of 86 months (range, 60-177 months). There were 23 cases with tumor recurrence or distant metastasis. There were similar 5-year DFS rates and DFS between the ET and non-ET groups, even for those with high risk factors. Conversely, 37.04% of patients suffered from adverse events after ET, which were significantly higher than those in the non-ET group.ConclusionET after mastectomy did not benefit patients with HR+ DCIS for their DFS, rather increased adverse events in those patients. Therefore, ET after mastectomy may not be recommended for patients with HR+ DCIS, even for those with high-risk factors, such as multifocal, microinvasive and higher T stage.FundingThis study was supported by grants from Outstanding Scientific Fund of Shengjing Hospital (201803) and Outstanding Young Scholars of Liaoning Province (2019-YQ-10).

Gallium nitride (GaN)-on-diamond technology offers key parameters of high thermal conductivity, high power density, high electrical resistivity and small form factor at both the device and system levels, making GaN-on-diamond power amplifier devices very attractive for high-power radio-frequency (RF) applications, such as commercial base stations, satellite communications and defence applications. Current GaN-on-diamond integration technology involves either a diamond growth process or a diamond bonding process, both of which require precise interface engineering with appropriate interfacial layers. While such interfacial layers are of vital importance to make high-quality GaN-on-diamond integration possible, they also contribute to a large portion of the effective thermal boundary resistance (TBReff) at the interface, which has to be minimized to justify the benefit of GaN-on-diamond technology compared with the mainstream GaN on silicon carbide (SiC) technology. In this paper, we review the ongoing effort to develop interface engineering processes that position GaN-on-diamond as a promising technology for enabling the next generation of power devices.