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Promoting the advancement of the structure and function of metastable substances is challenging but worthwhile. In particular, how to harness the entangled state and evolution path of labile porous structures has been at the forefront of research in molecular self-assembly. In this work, the metastable structures of polyoxovanadate-based metal-organic polyhedra (VMOPs) can be manually regulated, including separation of the interlocked aggregate by a ligand-widening approach as well as transformation from a tetrahedral to capsule-like scaffold via a vertice-remodeling strategy. In these processes, intra- and intermolecular π···π and C-H···π interactions have been recognized as the primary driving forces. Besides being responsible for commanding the structural evolvement of VMOPs, such weak interactions were able to program their spatial arrangements and hence the adsorption performances for dye and iodine. The successful use of such a weak force-dominated design concept beacons a feasible route for customization of the function-oriented metastable structures. Separation and transformation of the interlocked metastable VMOPs have been achieved via the respective ligand-widening approach and vertice-remodeling strategy. Not only their structures but also adsorption features could be well regulated by such a weak force-dominated design concept.

Given the limitations of micromechanical experiments and molecular dynamics simulations, the normal compression process of clay aggregates was simulated under different vertical pressures ( P ), numbers of particles, loading methods, and environments by a Gay-Berne potential model. On the basis of the variations of particle orientation and the distribution of stacks, the evolution of deformation and stresses was elucidated. The results showed that the effects of the pressure level and loading environment on the deformation were significant. In the range of 0.1-10 MPa, the changes in the void ratio were essentially the evolution of the distribution of stacks determined by attractive short-range van der Waals interactions. The deformation under constant pressure was larger than that under step loading. Because the interactions between clay particles were mainly controlled by mechanical force when in the range of 40-100 MPa, the void ratios under various loading conditions were consistent. It was also found that changes in three-dimensional stresses during compression were dependent on those of the distribution of stacks. In the vacuum environment, owing to the lateral movement of interlocked small stacks, the horizontal stress decreased. The lateral pressure coefficients ( k ) were greater in an atmospheric environment because the anisotropic particle orientation was relatively less obvious. In the range of 10-100 MPa, when the loading path became longer, k was similar in vacuum but became smaller in an atmosphere. If the initial loading pressure was increased, the number of large stacks sharply increased and the anisotropy was significant in a vacuum environment, which was less prone to lateral expansion. In contrast, more consistent particle arrangements were maintained in an atmosphere. This work will be conducive to explaining experimental observations of long-term ripening.

Background: Owing to the cytotoxic effect, it is challenging for clinicians to decide whether post-operative adjuvant therapy is appropriate for a non-small cell lung cancer (NSCLC) patient. Radiomics has proven its promising ability in predicting survival but research on its actionable model, particularly for supporting the decision of adjuvant therapy, is limited., Methods: Pre-operative contrast-enhanced CT images of 123 NSCLC cases were collected, including 76, 13, 16, and 18 cases from R01 and AMC cohorts of The Cancer Imaging Archive (TCIA), Jiangxi Cancer Hospital and Guangdong Provincial People's Hospital respectively. From each tumor region, 851 radiomic features were extracted and two augmented features were derived therewith to estimate the likelihood of adjuvant therapy. Both Cox regression and machine learning models with the selected main and interaction effects of 853 features were trained using 76 cases from R01 cohort, and their test performances on survival prediction were compared using 47 cases from the AMC cohort and two hospitals. For those cases where adjuvant therapy was unnecessary, recommendations on adjuvant therapy were made again by the outperforming model and compared with those by IBM Watson for Oncology (WFO)., Results: The Cox model outperformed the machine learning model in predicting survival on the test set (C-Index: 0.765 vs. 0.675). The Cox model consists of 5 predictors, interestingly 4 of which are interactions with augmented features facilitating the modulation of adjuvant therapy option. While WFO recommended no adjuvant therapy for only 13.6% of cases that received unnecessary adjuvant therapy, the same recommendations by the identified Cox model were extended to 54.5% of cases (McNemar's test p = 0.0003)., Conclusions: A Cox model with radiomic and augmented features could predict survival accurately and support the decision of adjuvant therapy for bettering the benefit of NSCLC patients., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Chan, Ding, Shao, Huang, Hui, Cho, Wong, Tong, Chiu, Huang and Zhou.)

There was rapid growth of telehealth practice during the COVID-19 outbreak in 2020. In surgery, there were beneficial effects in terms of saving time and avoiding physical contact between healthcare professionals and patients when using telehealth in the delivery of perioperative care. As telehealth is gaining momentum, the evolving ethical and medico-legal challenges arising from this alternative mode of doctor-patient interaction cannot be underestimated. With reference to the "Ethical Guidelines on Practice of Telemedicine" issued by the Medical Council of Hong Kong and some published court and disciplinary cases from other common law jurisdictions, this article discusses relevant ethical and medico-legal issues in telehealth practice with emphasis on the following areas: duty of care; communication and contingency; patient-centred care and informed consent; limitations and standard of care; keeping medical records, privacy, and confidentiality; and cross-territory practice. Whilst existing ethical and legal obligations of practicing medicine are not changed when telehealth is used as opposed to in-person care, telehealth practitioners are advised to familiarize themselves with the ethical guidelines, to keep abreast of the medico-legal developments in this area, and to observe the licensure requirements and regulatory regimes of both the jurisdiction where they practice and where their patients are located., (© 2021 College of Surgeons of Hong Kong.)

Objective: To compare the applied value of the pressure aggravation test and breath aggravation test in the diagnosis of early acute appendicitis., Methods: A total of 101 cases with epigastralgia, middle or upper abdomen pain, disease duration within 6 hours undergoing pressure aggravation test and breath aggravation test respectively in our hospital between October 2010 and December 2012 were prospectively enrolled. By comparing with the postoperative pathological diagnosis (early acute appendicitis and other abdominal pain), the sensitivity and specificity of these two tests were calculated. Through analyzing the receiver operating characteristic (ROC) curve, the diagnostic value of early acute appendicitis was evaluated., Results: Fifty-two cases of early acute appendicitis and 49 cases of other abdominal pain were diagnosed by postoperative pathologic results. The sensitivity and specificity of the pressure aggravation test were 87.5% and 72.1% and of the breath aggravation test were 53.8% and 83.7% respectively. The area under the ROC curve of the pressure aggravation test was 0.786 (95% CI: 0.693-0.878), similar to that of the breath aggravation test (0.688, 95% CI: 0.583-0.792)., Conclusion: The pressure aggravation test has higher value to diagnose early acute appendicitis, while the breath aggravation test has better specificity.

The kinetics of aggregation of two pyromellitamide gelators, tetrabutyl- (C4) and tetrahexyl-pyromellitamide (C6), in deuterated cyclohexane has been investigated by small angle neutron scattering (SANS) for up to 6 days. The purpose of this study was to improve our understanding of how self-assembled gels are formed. Short-term (< 3 h) time scales revealed multiple phases with the data for the tetrabutylpyromellitamide C4, indicating one-dimensional stacking and aggregation corresponding to a multifiber braided cluster arrangement that is about 35 Å in diameter. The corresponding tetrahexylpyromellitamide C6 data suggest that the C6 also forms one-dimensional stacks but that these aggregate to a thicker multifiber braided cluster that has a diameter of about 62 Å. Over a longer period of time, the radius, persistence length, and contour length all continue to increase in 6 days after cooling. These data suggest that structural changes in self-assembled gels occur over a period exceeding several days and that fairly subtle changes in the structure (e.g., tail-length) can influence the packing of molecules in self-assembled gels on the single-to-few fiber bundle stage.

The gelation and aggregation properties of a newly synthesized structurally simplified tetrahexyl pyromellitamide 2 have been studied and compared to the previously reported tetra(ethylhexanoate) pyromellitide 1, indicating that the ester groups in the latter significantly impede its aggregation. Morphology studies (AFM and TEM) on the aggregates formed by tetrahexyl pyromellitamide 2 in cyclohexane revealed highly uniform aggregates with different dimensions at different starting concentrations, suggesting that this molecule aggregates in a hierarchical fashion from a one-dimensional supramolecular polymer through hollow tubes or compressed helices to a network structure and then to a gel. This hypothesis is further supported by viscosity measurements that indicate a crossover point where individual supramolecular fibers get entangled at concentrations above ca. 3 mM in cyclohexane. Addition of 1 equiv of tetraalkylammonium salts of chloride or bromide, however, caused the viscosities of these pyromellitamide solutions to drop by a factor of 2-3 orders of magnitude, demonstrating the sensitivity of these aggregates to the presence of small anions. The sensitivity to anions does depend on the solubility of the salts used as small anion salts with little solubility in cyclohexane did not show this effect. Time-dependent viscosity studies showed that the aggregation of pyromellitamide 2 follows an exponential rate law, possibly related to the columnar rearrangements that are associated with the observed 6 angstroms contraction in d spacing in the XRD pattern of these gels. These results, particularly on the importance of kinetics of aggregation of self-assembled pyromellitamide gels, will be useful for future development of related materials for a number of applications, including tissue engineering and drug delivery.

Zebrafish Alk8 is a novel type I TGFbeta family member receptor that functions in Bmp signaling pathways to direct dorsoventral patterning of the early embryo. Both alk8 mRNA and protein is expressed in a variety of tissues, including teeth, eye, heart, blood, notochord, muscle, neural tissues, and neural crest cells (NCC's). Previous functional analyses, performed by microinjection of constitutively active (CA) and dominant negative (DN) alk8 mRNAs, revealed early developmental requirements for alk8. The alk8 gene is expressed ubiquitously as a maternal mRNA, and later exhibits more restricted zygotic gene expression. To identify regulatory elements directing the temporospatial expression of alk8, we characterized fluorescence in transgenic zebrafish lines containing alk8 promoter/green fluorescent protein (GFP) reporter constructs. This approach identified transgenic alk8(2.6):GFP lines that first expressed GFP in early stage 1A oocytes, and maintained GFP expression throughout the embryo only for the first 72 hours of development. Analysis of the nucleotide sequence of the 2.6 kb alk8 promoter element provides insight into the regulation of maternal alk8 gene expression. Significantly, the identified maternal alk8 promoter is one of only two maternal-specific promoter elements that have been described to date.