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Purpose The aim of this study was to determine the risk of severe postoperative complications (SPCs) in patients with gastric cancer and to construct a nomogram based on independently related factors to identify high-risk patients.Methods We retrospectively analyzed 297 consecutive patients undergoing gastrectomy in this multicenter study. Sarcopenia was diagnosed by preoperative computed tomography of the L3 skeletal muscle area. Nutritional status was assessed according to the Global Leadership Initiative on Malnutrition criteria. According to the Clavien–Dindo classification system, SPCs were classified as C-D Grade ≥ IIIa. A nomogram consisting of the independent risk factors was constructed to quantify the individual risk of SPCs.Results Of the 297 patients analyzed in this study, 86 (28.96%) were diagnosed with malnutrition, 55 (18.52%) were diagnosed with sarcopenia, and 24 (8.08%) were diagnosed with SPCs. Patients who developed SPCs had longer hospital stays (SPCs vs. non-SPCs: 23 vs. 11 days, P P P P = 0.017), combined resection (P = 0.028), and duodenostomy (P = 0.001) independently predicted the occurrence of SPCs. The nomogram exhibited good discrimination, with a discriminant consistency index of 0.822, and the calibration was also excellent.Conclusions Sarcopenia, malnutrition, combined resection and duodenostomy are independent predictors of SPCs. Our nomogram exhibited good discrimination and was practical for identifying patients at high risk of SPCs.

Surfaces grafted with polyelectrolyte chains for excellent performance in protein antifouling are highly desired in many applications, such as biomedical implants and devices. In general, the adsorbing/resisting behaviors of proteins can be mainly attributed to the electrostatic interactions that are associated with the charge properties of proteins and polyelectrolytes. By coarse-grained molecular dynamics simulations, we examined the self-assembled structures of polyanion and polyzwitterion brushes as well as the interactions on negatively and positively charged proteins. We found that in addition to charges, the structural polarization induced by self-assembly with a certain charge distribution shows significant influences on protein behavior. The large-scale dipole-dipole interactions between brushes and proteins can dominate the behavior of proteins on the brushes under certain circumstances. To ensure simulation accuracy, we compared two models and found a polar Martini model that explicitly treats electrostatic interactions as long-ranged ones, giving a more reasonable structural description compared with the normal Martini model that truncates electrostatic interactions.

Longitudinal critically refracted (LCR) ultrasonic waves and magnetic Barkhausen noise (MBN) are two commonly used methods for measuring the residual stress of steel. Both of these methods have distinct advantages and disadvantages that need to be taken into consideration when selecting the most appropriate technique for measuring residual stress under specific circumstances. This issue is experimentally investigated in this paper by comparing the linearity, sensitivity and repeatability of these two measurement techniques for evaluating the stress within Q345 steel samples subjected to different levels of applied tensile stress. The time-of-flight (TOF) of LCR waves is demonstrated to conform almost perfectly with the applied stress in a linear relationship, while a similarly perfect confirmation is obtained for the root mean square (RMS) voltage of MBN signals to a quadratic curve. The results demonstrate that the RMS voltage of MBN signals is much more sensitive than the TOF of LCR waves to variations in surface stress, where the application of a 240 MPa tensile stress increases the RMS voltage of MBN signals by about 140% relative to that of the unstressed sample, while the TOF of LCR waves increases by less than 0.15% under corresponding conditions. Multiple testing of the same specimen demonstrates that MBN measurements more closely coincide than those of LCR waves. Therefore, MBN exhibits superior repeatability to LCR waves.

Chemically recyclable semi-fluorinated polymers are demonstrated for the first time, and the hydrophobicity, self-assembly, and post-polymerization functionalization of these polymers are explored.

The composition, sequence, length, and type of glycosidic linkages of polysaccharides profoundly affect their biological and physical properties. However, investigation of the structure-function relationship of polysaccharides is hampered by accessing well-defined polysaccharides in sufficient quantities. Here, we report a chemical approach to precision polysaccharides with native glycosidic linkages via living cationic ring-opening polymerization of 1,6-anhydrosugars. We synthesized well-defined polysaccharides with tunable molecular weight, low dispersity, and excellent regio- and stereoselectivity using a boron trifluoride etherate catalyst and glycosyl fluoride initiators. Computational studies revealed that the reaction propagated through the monomer alpha-addition to the oxocarbenium and was controlled by the reversible deactivation of the propagating oxocarbenium to form the glycosyl fluoride dormant species. Our method afforded a facile and scalable pathway to multiple biologically relevant precision polysaccharides, including D-glucan, D-mannan, and an unusual L-glucan. We demonstrated that catalytic depolymerization of precision polysaccharides efficiently regenerated monomers, suggesting their utility as a class of chemically recyclable materials with tailored thermal and mechanical properties.

The growing consumption of synthetic polymers and the accumulation of polymer waste have led to a pressing need for new routes to sustainable materials. Achieving a closed-loop polymer economy via chemical recycling to monomer (CRM) is one such promising route. Our group recently reported a new CRM system based on polymers prepared by ring-opening metathesis polymerization (ROMP) of trans-cyclobutane fused cyclooctene (tCBCO) monomers. This system offers several key advantages, including the ease of polymerization at ambient temperatures, quantitative depolymerization to monomers under mild conditions, and a broad range of functionalities and thermomechanical properties. Here, we outline detailed protocols for the preparation of tCBCO-based monomers and their corresponding polymers, including the preparation of elastic polymer networks and compression molding of linear thermoplastic polymers. We also outline the preparation of high ring strain E-alkene tCBCO monomers and their living polymerization. Finally, the procedures for the depolymerization of linear polymers and polymer networks are also demonstrated.

Background To evaluate the immune function of gastric cancer patients after single-incision laparoscopic distal gastrectomy (SIDG) or multiport laparoscopic distal gastrectomy (MLDG) guided by enhanced recovery after surgery (ERAS). Methods A retrospective cohort study was performed on 120 patients who underwent laparoscopic distal gastrectomy for gastric cancer. The patients were divided into two groups according to operation method: group A (MLDG) and group B (SIDG), both guided by ERAS concept. The indicators reflecting immune function and inflammation, such as CD3+, CD4+, CD8+ and NK cell count, CD4+/CD8+ cell ratios, IgA, IgM and IgG levels, C-reactive protein (CRP), total lymphocyte count (TLC) and neutrophil-to-lymphocyte ratio (NLR) were tested 3 days and 7 days after surgery. Results The skin incision length of patients in group B was significantly shorter than that in group A, but the operation time was significantly longer in group B than that in group A (P P P > 0.05). On the 7th day after surgery, the immune indexes of both groups recovered somewhat, approaching the preoperative level (P > 0.05). Inflammation indexes increased 3 days after surgery and decreased 7 days after surgery in both groups, among them the CRP level in group A was higher than that in group B (P Conclusion Compared with MLDG guided by ERAS, SIDG under the guidance of the ERAS concept has better cosmetic effect and similar effect on immune function of gastric cancer patients.

Polymers with low ceiling temperatures (Tc) are highly desirable as they can depolymerize under mild conditions, but they typically suffer from demanding synthetic conditions and poor stability. We envision that this challenge can be addressed by developing high-Tc polymers that can be converted into low Tc polymers on demand. Here, we demonstrate the mechanochemical generation of a low-Tc polymer, poly(2,5-dihydrofuran) (PDHF), from an unsaturated polyether that contains cyclobutane-fused THF in each repeat unit. Upon mechanically induced cycloreversion of cyclobutane, each repeat unit generates three repeat units of PDHF. The resulting PDHF completely depolymerizes into 2,5-dihydrofuran in the presence of a ruthenium catalyst. The mechanochemical generation of the otherwise difficult-to-synthesize PDHF highlights the power of polymer mechanochemistry in accessing elusive structures. The concept of mechanochemically regulating Tc of polymers can be applied to develop next-generation sustainable plastics.

A promising solution to address the challenges in plastics sustainability is to replace current polymers with chemically recyclable ones that can depolymerize into their constituent monomers to enable the circular use of materials. Despite some progress, few depolymerizable polymers exhibit the desirable thermal stability and strong mechanical properties of traditional polymers. Here we report a series of chemically recyclable polymers that show excellent thermal stability (decomposition temperature >370 °C) and tunable mechanical properties. The polymers are formed through ring-opening metathesis polymerization of cyclooctene with a trans-cyclobutane installed at the 5 and 6 positions. The additional ring converts the non-depolymerizable polycyclooctene into a depolymerizable polymer by reducing the ring strain energy in the monomer (from 8.2 kcal mol-1 in unsubstituted cyclooctene to 4.9 kcal mol-1 in the fused ring). The fused-ring monomer enables a broad scope of functionalities to be incorporated, providing access to chemically recyclable elastomers and plastics that show promise as next-generation sustainable materials.

Reachability queries processing has been extensively studied during the past decades. Many approaches have followed the line of designing 2-hop labels to ensure acceleration. Considering its index size cannot be bounded, researchers have proposed to use a part of nodes to construct partial 2-hop labels (p2HLs) to cover as much reachability information as possible. We achieved better query performance using p2HLs with a limited index size and index construction time. However, the adoption of p2HLs was based on intuition, and the number of nodes used to generate p2HLs was fixed in advance blindly, without knowing its applicability. In this paper, we focused on the problem of efficiently computing a reachability ratio (RR) in order to obtain RR-aware p2HLs. Here, RR denoted the ratio of the number of reachable queries that could be answered by p2HLs over the total number of reachable queries involved in a given graph. Based on the RR, users could determine whether p2HLs should be used to answer the reachability queries for a given graph and how many nodes should be chosen to generate p2HLs. We discussed the difficulties of RR computation and propose an incremental-partition algorithm for RR computation. Our rich experimental results showed that our algorithm could efficiently obtain the RR and the overall effects on query performance by different p2HLs. Based on the experimental results, we provide our findings on the use p2HLs for a given graph for processing reachability queries.

A maximal clique ( ${MC}$ ) is a complete subgraph satisfying that no other cliques can take it as their proper subgraph. Given an uncertain graph, the $top\text{-}K\,\,{MC}\text{s}$ enumeration problem studies how to return $k {MC}\text{s}$ with the highest rank value. Existing algorithms rank ${MC}\text{s}$ according to their probabilities, thus usually return ${MC}\text{s}$ with higher probabilities but less number of vertices, and fail to return large ${MC}\text{s}$ that convey more useful information. Considering this problem, this paper studies the problem of enumerating $top\text{-}K\,\,{MC}\text{s}$ . Our approach returns $k {MC}\text{s}$ with the most number of vertices satisfying that their probabilities $\geq \alpha $ , where each ${MC}$ is called an $\alpha $ - ${MC}$ , and computing $k$ largest $\alpha $ - ${MC}\text{s}$ is called as $(k,\alpha)$ - ${MC}\text{s}$ . We propose an efficient $(k,\alpha)$ - ${MC}\text{s}$ enumeration algorithm, $Top\text{-}KMC$ , which works in three steps, including partition, enumeration and verification. Here, partition means that we compute the set $\mathcal {M}$ of all ${MC}\text{s}$ without considering the probability information, as if the graph is partitioned into a set of subgraphs. Enumeration means that we compute $\alpha $ - ${MC}\text{s}$ from each ${MC}$ of $\mathcal {M}$ . As each such subgraph is an ${MC}$ , the cost of computing common neighbors for finding $\alpha $ - ${MC}\text{s}$ can be reduced. Verification means that we need to verify whether an $\alpha $ - ${MC}$ is a subgraph of another $\alpha $ - ${MC}$ . If not, it is an $\alpha $ - ${MC}$ ; otherwise, it is a useless $\alpha $ - ${MC}$ and should be removed. We further propose an optimized algorithm $Top\text{-}KMC+$ to reduce both time and space by merging the above three steps into a whole step. The experimental results on real datasets show that both $Top\text{-}KMC$ and $Top\text{-}KMC+$ can return $k$ largest $\alpha $ - ${MC}\text{s}$ efficiently.

A new biobased low dielectric resin derived from vanillin and guaiacol has been synthesized. Thanks to the low polarizability of hexafluorocyclobutyl units, this resin exhibits good dielectric properties with an average dielectric constant (Dk) of 2.67 and a dielectric dissipation factor (Df) of 2.9 × 10−3 at a frequency range from 0.15 MHz to 20 MHz. This resin also displays high dimensional stability with a coefficient of thermal expansion (CTE) of 46.3 ppm per °C from 25 °C to 180 °C and a glass transition temperature (Tg) of 243 °C. In addition, the polymer films on the silicon wafers also exhibit good uniformity, flatness, and high hydrophobicity, suggesting that this bio-based resin is suitable as an encapsulation for applications in the microelectronic industry.

Enhanced Recovery after Surgery has been proven effective for patients with gastrointestinal cancer. But radical enhanced recovery could also lead to adverse clinical outcomes. Compared with reports on the estimation of successful implementation of enhanced recovery, studies on risk factors of enhanced recovery failure are still lacking. A retrospective analysis was carried out on 102 patients in ERAS who underwent elective colon cancer surgery. This study included 102 patients with colon cancer between 2015 and 2019, defining enhanced recovery failure as postoperative length of stay over 10 days, stay in ICU over 24 h after surgery, reoperation, death, or unplanned readmission within 30 days after surgery. Univariate and multivariate analyses were performed to explore potential risk factors of failure. Aged ≥ 75, open operation, number of drainage tube over 1, re-urethral catheterization, and Clavien-Dindo grade over 2 were associated with ERAS failure, according to univariate analysis. Multivariate analysis showed that age ≥ 75 [OR 7.231; P = 0.009]; open operation (OR 3.599; P = 0.021); and number of drainage tube over 1 (OR 3.202; P = 0.020) were independent risk factors for ERAS failure. We found age ≥ 75, open operation, and number of drainage tube over 1 are independent risk factors associated with ERAS failure after colon cancer surgery.

Developing graphene-like two-dimensional materials naturally possessing a band gap has sparked enormous interest. Thanks to the inherent wide band gap and high mobility in the 2D plane, covalent organic frameworks containing triazine rings (t-COFs) hold great promise in this regard, whilst the synthesis of single-layer t-COFs remains highly challenging. Herein, we present the fabrication of a well-defined graphene-like t-COF on Au(111). Instead of single/multiple-step single-type reactions commonly applied for on-surface synthesis, distinct stepwise on-surface reactions, including alkynyl cyclotrimerization, C−O bond cleavage, and C−H bond activation, are triggered on demand, leading to product evolution in a controlled step-by-step manner. Aside from the precise control in sophisticated on-surface synthesis, this work proposes a single-atomic-layer organic semiconductor with a wide band gap of 3.41 eV.

Enhanced recovery after surgery programs has been applied extensively in laparoscopic colorectal surgery. However, several studies have found that some patients fail from ERAS programs. It is important to identify these patients so that remedial action can be taken in a timely manner. The aim of this study was to perform a systematic review of ERAS failure and related risk factors following laparoscopic colorectal surgery. A literature search of the PubMed, EMBASE, OVID, and Cochrane databases was performed. The search strategy involved terms related to ERAS, failure, and colorectal surgery. The main outcomes were definitions of ERAS failure and related risk factors. Seven studies including 1463 patients were analyzed. The definition of ERAS failure was mostly associated with a prolonged postoperative length-of-stay (poLOS). Twenty-four kinds of identified risk factors were divided into three parts, the operative part, the pathophysiological part, and the ERAS elements, of which operative factors including more intraoperative blood loss and longer operative duration were the most frequently identified. ERAS failure was mostly related to a prolonged poLOS, and operative factors were the most frequently identified risk factors for ERAS failure following laparoscopic colorectal surgery. These findings will help physicians to take remedial action in a timely manner. Nonetheless, high-quality randomized controlled trials following a standardized framework for evaluating ERAS programs are needed in the future.

Single-incision laparoscopic sleeve gastrectomy (SILSG) has been proposed as an alternative to conventional laparoscopic sleeve gastrectomy (CLSG) in obese patients. This study aims to compare the surgical outcomes of these two techniques. A meta-analysis of existing literature obtained through a systematic literature search in the PubMed, EMBASE, and Cochrane Library CENTRAL databases from 2009 to 2019 was conducted. Eleven articles including 1168 patients were analyzed. Patients in the SILSG group reported greater satisfaction with cosmetic scar outcomes than those in the CLSG group (SMD = 2.47, 95% CI = 1.10 to 3.83, P = 0.00). There was no significant difference between the SILSG group and the CLSG group regarding operative time, intraoperative estimated blood loss, conversion rate, intraoperative complications, length of hospital stay, postoperative analgesia, postoperative complications, excess weight loss (EWL), and improvements in comorbidities (P > 0.05). Compared to CLSG, SILSG resulted in improved cosmetic satisfaction and showed no disadvantages in terms of surgical outcomes; thus, SILSG can serve as an alternative to CLSG for obese patients. Nonetheless, high-quality randomized controlled trials (RCTs) with large study populations and long follow-up periods are needed.

Two flexible and colorless polymers are synthesized based on a phosphorus-containing derivative of a bio-based aromatic aldehyde (4-hydroxybenzaldehyde) by a thiol-ene reaction. Thanks to the high ...

Two fluoro-containing low dielectric polymers have been successfully prepared based on thermo-crosslinkable trifluorovinyl ether (TFVE) monomers with big tetrahedral units (adamantane and spirobifluorene). These polymers exhibit an average dielectric constant (Dk) of lower than 2.6, and the polymer with adamantane units displays the lowest Dk of 2.26 and an average dielectric loss (Df) of 1.14 × 10−3 at a range of frequencies from 1 to 10 MHz. In contrast, the polymer with spirobifluorene units displays a Dk of 2.54 and a Df of 1.53 × 10−3. Such results are attributed to the existence of intrinsic micropores produced by the big adamantane and spirobifluorene units in the polymers. Positron annihilation lifetime spectroscopy (PALS) indicates two different micropores in both the polymers, with sizes of 2.354/4.354 and 2.949/4.408 A, respectively. Because the polymer with adamantane units possesses bigger pore sizes, it shows a lower dielectric constant. These data mean that the polymer with adamantane units is suitable for use as encapsulation resins of integrated circuit (IC) dies for applications in the microelectronics industry.