Oncological prognosis and morbidity of hepatectomy in elderly patients with hepatocellular carcinoma: a propensity score matching and multicentre study.

PURPOSE: With increasing life expectancy, the number of elderly patients (≥ 65 years) with hepatocellular carcinoma (HCC) has steadily increased. Hepatectomy remains the first-line treatment for HCC patients. However, the prognosis of hepatectomy for elderly patients with HCC remains unclear. METHODS: Clinical and follow-up data from 1331 HCC patients who underwent surgery between 2008 and 2020 were retrospectively retrieved from a multicentre database. Patients were divided into elderly (≥ 65 years) and non-elderly (< 65 years) groups, and PSM was used to balance differences in the baseline characteristics. The postoperative major morbidity and cancer-specific survival (CSS) of the two groups were compared and the independent factors that were associated with the two study endpoints were identified by multivariable regression analysis. RESULTS: Of the 1331 HCC patients enrolled in this study, 363 (27.27%) were elderly, while 968 (72.73%) were not. After PSM, 334 matched samples were obtained. In the propensity score matching (PSM) cohort, a higher rate of major morbidity was found in elderly patients (P = 0.040) but the CSS was similar in the two groups (P = 0.087). Multivariate analysis revealed that elderly age was not an independent risk factor associated with high rates of major morbidity (P = 0.117) or poor CSS (P = 0.873). The 1-, 3- and 5-year CSS rates in the elderly and non-elderly groups were 91.0% versus 86.2%, 71.3% versus 68.8% and 55.9% versus 58.0%, respectively. Preoperative alpha fetoprotein (AFP) level, Child‒Pugh grade, intraoperative blood transfusion, extended hemi hepatectomy, and tumour diameter could affect the postoperative major morbidity and preoperative AFP level, cirrhosis, Child‒Pugh grade, macrovascular invasion, microvascular invasion (MVI), satellite nodules, and tumor diameter were independently and significantly associated with CSS. CONCLUSION: Age itself had no significant effect on the prognosis of elderly patients with HCC after hepatectomy. Hepatectomy can be safely performed in elderly patients after cautious perioperative management.

Why Are There so Many Plant Species That Transiently Flush Young Leaves Red in the Tropics?

Delayed greening of young leaves is a ubiquitous and visually striking phenomenon in the tropics. Here, we investigated the potential ecological functions of red coloration patterns in young leaves. To detect any protective function of the red coloration on the young leaves, leaf damage by insect herbivores was recorded in the field. To determine capacity for chemical defense, the concentrations of tannins and anthocyanins were measured in both young and mature leaves. To test the hypothesis that anthocyanins function as photo-protective molecules, chlorophyll content, maximum photochemical efficiency of PSII (F v /Fm ), non-photochemical quenching (NPQ), and effective quantum yield of PSII (ΦPSII ) were measured in the field. Phylogenetic relationships were analyzed to test the relationary significance of the occurrence of redness in young leaves. Compared to the coloration in non-red leaves, young red leaves had significant higher anthocyanins and tannins content and lower herbivore damages. Young, red leaves had the lowest Fv /Fm values, which were significantly lower than those of non-red leaves. NPQ values in young red leaves were comparable to those of other groups. Although young red leaves had high ΦPSII , these values were significantly lower than those of the other three groups. The results suggest that the red coloration of young leaves protects them from insect herbivory primary by chemical defense through high concentrations of tannins and anthocyanins. Additionally, low Fv /Fm values in young red leaves indicate that anthocyanins might not be functioning as light attenuators to compensate for insufficient photo-protection mediated by NPQ. And finally, red coloration in young leaves is predominantly a result of adaptation to heavy herbivory stress but without significant intrinsic phylogenetic relationship of plant species.

Thermodynamic rules for zeolite formation from machine learning based global optimization.

While the [TO4] tetrahedron packing rule leads to millions of likely zeolite structures, there are currently only 252 types of zeolite frameworks reported after decades of synthetic efforts. The subtle synthetic conditions, e.g. the structure-directing agents, pH and the feed ratio, were often blamed for the limited zeolite types due to the complex kinetics. Here by developing machine learning global optimization techniques, we are now able to establish the global potential energy surface of a typical zeolite system, Si x Al y P z O2H y-z with 12 T atoms (T: Si, Al and P) that is the general formula shared by CHA, ATS, ATO and ATV zeolite frameworks. After analyzing more than 106 minima data, we identify thermodynamic rules on energetics and local bonding patterns for stable zeolites. These rules provide general guidelines to classify zeolite types and correlate them with synthesis conditions. The machine learning based atomistic simulation thus paves a new way towards rational design and synthesis of stable zeolite frameworks with desirable compositions.

Donor-Acceptor Conjugated Macrocycles: Synthesis and Host-Guest Coassembly with Fullerene toward Photovoltaic Application.

Electron-rich (donor) and electron-deficient (acceptor) units to construct donor-acceptor (D-A) conjugated macrocycles were investigated to elucidate their interactions with electron-deficient fullerene. Triphenylamine and 4,7-bisthienyl-2,1,3-benzothiadiazole were alternately linked through acetylene, as the donor and acceptor units, respectively, for pentagonal 3B2A and hexagonal 4B2A macrocycles. As detected by scanning tunneling microscopy, both D-A macrocycles were found to form an interesting concentration-controlled nanoporous monolayer on highly oriented pyrolytic graphite, which could effectively capture fullerene. Significantly, the fullerene filling was cavity-size-dependent with only one C70 or PC71BM molecule accommodated by 3B2A, while two were accommodated by 4B2A. Density functional theory calculations were also utilized to gain insight into the host-guest systems and indicted that the S···π contact is responsible for stabilizing these host-guest systems. Owing to the ellipsoidal shape of C70, C70 molecules are standing or lying in molecular cavities depending on the energy optimization. For the 3B2A/PC71BM blended film, PC71BM was intercalated into the cavity formed by the macrocycle 3B2A and provided excellent power conversion efficiency despite the broad band gap (2.1 eV) of 3B2A. This study of D-A macrocycles incorporating fullerene provides insights into the interaction mechanism and electronic structure in the host-guest complexes. More importantly, this is a representative example using D-A macrocycles as a donor to match with the spherical fullerene acceptor for photovoltaic applications, which offer a good approach to achieve molecular scale p-n junctions for substantially enhanced efficiencies of organic solar cells through replacing linear polymer donors by cyclic conjugated oligomers.

Pre-activation of mesenchymal stem cells with TNF-α, IL-1ß and nitric oxide enhances its paracrine effects on radiation-induced intestinal injury.

Conditioned medium from mesenchymal stem cells (MSC-CM) may represent a promising alternative to MSCs transplantation, however, the low concentrations of growth factors in non-activated MSC-CM hamper its clinical application. Recent data indicated that the paracrine potential of MSCs could be enhanced by inflammatory factors. Herein, we pre-activated bone-marrow-derived MSCs under radiation-induced inflammatory condition (MSC(IEC-6(IR))) and investigated the evidence and mechanism for the differential effects of MSC-CM(IEC-6(IR)) and non-activated MSC-CM on radiation-induced intestinal injury (RIII). Systemic infusion of MSC-CM(IEC-6(IR)), but not non-activated MSC-CM, dramatically improved intestinal damage and survival of irradiated rats. Such benefits may involve the modulation of epithelial regeneration and inflammation, as indicated by the regeneration of intestinal epithelial/stem cells, the regulation of the pro-/anti-inflammatory cytokine balance. The mechanism for the superior paracrine efficacy of MSC(IEC-6(IR)) is related to a higher secretion of regenerative, immunomodulatory and trafficking molecules, including the pivotal factor IGF-1, induced by TNF-α, IL-1ß and nitric oxide partially via a heme oxygenase-1 dependent mechanism. Together, our findings suggest that pre-activation of MSCs with TNF-α, IL-1ß and nitric oxide enhances its paracine effects on RIII via a heme oxygenase-1 dependent mechanism, which may help us to maximize the paracrine potential of MSCs.

Reactivity Descriptor in Solid Acid Catalysis: Predicting Turnover Frequencies for Propene Methylation in Zeotypes.

Recent work has reported the discovery of metal surface catalysts by employing a descriptor-based approach, establishing a correlation between a few well-defined properties of a material and its catalytic activity. This theoretical work aims for a similar approach in solid acid catalysis, focusing on the reaction between propene and methanol catalyzed by Brønsted acidic zeotype catalysts. Experimentally, the ammonia heat of adsorption is often used as a measure of the strength of acid sites. Using periodic DFT calculations, we show that this measure can be used to establish scaling relations for the energy of intermediates and transition states, effectively describing the reactivity of the acid site. This allows us to use microkinetic modeling to predict a quantitative relation between the ammonia heat of adsorption and the rate of propene methylation from first principles. We propose that this is the first step toward descriptor-based design of solid acid catalysts.

Origin of Oxide sensitivity in gold-based catalysts: a first principle study of CO oxidation over Au supported on monoclinic and tetragonal ZrO2.

The catalytic performance of Au/oxide catalysts can vary significantly upon the change of oxide species or under different catalyst preparation conditions. Due to its complex nature, the physical origin of this phenomenon remains largely unknown. By extensive density functional theory calculations on a model system, CO oxidation on Au/ZrO2, this work demonstrates that the oxidation reaction is very sensitive to the oxide structure. The surface structure variation due to the transformation of the oxide phase or the creation of structural defects (e.g., steps) can greatly enhance the activity. We show that CO oxidation on typical Au/ZrO2 catalysts could be dominated by minority sites, such as monoclinic steps and tetragonal surfaces, the concentration of which is closely related to the size of oxide particle. Importantly, this variation in activity is difficult to understand following the traditional rules based on the O2 adsorption ability and the oxide reducibility. Instead, electronic structure analyses allow us to rationalize the results and point toward a general measure for CO + O2 activity, namely the p-bandwidth of O2, with important implications for Au/oxide catalysis.

Effective tuning of HOMO and LUMO energy levels by p-n diblock and triblock oligomer approaches.

A novel series of oligomers consisting of thiophene as a p-type unit and oxadiazole as an n-type unit were separately synthesized. On the basis of the characterization of photophysical and electrochemical properties, the structure-property relationships of the oligomers were investigated. Cyclic voltammogram studies showed that changing the number of thiophene and oxadiazole units could effectively modulate the electronic properties of the p-n diblock and triblock oligomers. The effect of molecular regiochemistry on electronic properties is also investigated. The observed electronic properties were consistent with theoretical calculations. These systems serve as excellent examples, demonstrating the band gap control principle in the p-n heterostructure oligomers.