Iterated Clique Reductions in Vertex Weighted Coloring for Large Sparse Graphs.

The Minimum Vertex Weighted Coloring (MinVWC) problem is an important generalization of the classic Minimum Vertex Coloring (MinVC) problem which is NP-hard. Given a simple undirected graph G=(V,E), the MinVC problem is to find a coloring s.t. any pair of adjacent vertices are assigned different colors and the number of colors used is minimized. The MinVWC problem associates each vertex with a positive weight and defines the weight of a color to be the weight of its heaviest vertices, then the goal is the find a coloring that minimizes the sum of weights over all colors. Among various approaches, reduction is an effective one. It tries to obtain a subgraph whose optimal solutions can conveniently be extended into optimal ones for the whole graph, without costly branching. In this paper, we propose a reduction algorithm based on maximal clique enumeration. More specifically our algorithm utilizes a certain proportion of maximal cliques and obtains lower bounds in order to perform reductions. It alternates between clique sampling and graph reductions and consists of three successive procedures: promising clique reductions, better bound reductions and post reductions. Experimental results show that our algorithm returns considerably smaller subgraphs for numerous large benchmark graphs, compared to the most recent method named RedLS. Also, we evaluate individual impacts and some practical properties of our algorithm. Furthermore, we have a theorem which indicates that the reduction effects of our algorithm are equivalent to that of a counterpart which enumerates all maximal cliques in the whole graph if the run time is sufficiently long.

Nickel-Catalyzed Markovnikov-Selective Hydrodifluoromethylation of Alkynes Using BrCF2 H.

A Markovnikov-selective hydrodifluoromethylation of alkynes with BrCF2 H via nickel catalysis is described. This protocol proceeds via a migratory insertion of nickel hydride to alkyne followed by a CF2 H-coupling, enabling straightforward access to diverse branched CF2 H-alkenes with high efficiency and exclusive regioselectivity. The mild condition applies to a wide array of aliphatic and aryl alkynes with good functional group compatibility. Mechanistic studies are presented to support the proposed pathway.

Catalyst-Free Intermolecular Sulfonyl/Fluoromethyl Heteroarylation of Vinyl Ethers via Visible-Light-Induced Charge Transfer.

We report a visible-light-induced three-component sulfonyl-heteroarylation of vinyl ethers with sulfinates and five-membered heteroaryl chlorides. This protocol proceeds via electron-donor-acceptor (EDA) complexes between sulfinates and heteroaryl chlorides, giving ß-sulfonyl alkyl five-membered heteroarenes with high efficiency and excellent regioselectivity under mild and catalyst-free conditions. Utilization of CF3 SO2 Na or CF2 HSO2 Na as coupling partners further achieves three-component fluoromethyl-arylation of vinyl ethers, furnishing a series of valuable CF3 /CF2 H-incorporated alkyl heterocycles under mild conditions.

Molecular signatures of circulating melanoma cells for monitoring early response to immune checkpoint therapy.

A subset of patients with metastatic melanoma have sustained remissions following treatment with immune checkpoint inhibitors. However, analyses of pretreatment tumor biopsies for markers predictive of response, including PD-1 ligand (PD-L1) expression and mutational burden, are insufficiently precise to guide treatment selection, and clinical radiographic evidence of response on therapy may be delayed, leading to some patients receiving potentially ineffective but toxic therapy. Here, we developed a molecular signature of melanoma circulating tumor cells (CTCs) to quantify early tumor response using blood-based monitoring. A quantitative 19-gene digital RNA signature (CTC score) applied to microfluidically enriched CTCs robustly distinguishes melanoma cells, within a background of blood cells in reconstituted and in patient-derived (n = 42) blood specimens. In a prospective cohort of 49 patients treated with immune checkpoint inhibitors, a decrease in CTC score within 7 weeks of therapy correlates with marked improvement in progression-free survival [hazard ratio (HR), 0.17; P = 0.008] and overall survival (HR, 0.12; P = 0.04). Thus, digital quantitation of melanoma CTC-derived transcripts enables serial noninvasive monitoring of tumor burden, supporting the rational application of immune checkpoint inhibition therapies.

Biventricular function after Ebstein anomaly repair from a single-center echocardiography study.

OBJECTIVE: We aimed to examine biventricular remodeling and function after Ebstein anomaly (EbA) surgical correction using echocardiographic techniques, particularly, the relations between the biventricular changes and the EbA types. METHODS: From April 2015 to August 2022, 110 patients with EbA were included in this retrospective study based on the Carpentier classification. Echocardiography assessments during the preoperative, early, and mid-term postoperative periods were performed. RESULTS: The 54 patients with types A and B EbA were included in group 1, whereas the 56 patients with types C and D were in group 2. Seventy-eight patients underwent surgical correction of EbA. The median age at operation was 8.8 years. During the mid-term follow-up, only 9.1% of the patients had moderate or severe tricuspid regurgitation. Right ventricular (RV) systolic function worsened in group 2 at discharge (fractional area change: 27.6 ± 11.2 vs. 35.4 ± 11.5 [baseline], P < 0.05; global longitudinal strain: -10.8 ± 4.4 vs. -17.9 ± 4.7 [baseline], P = 0.0001). RV function slowly recovered at a mean of 12 months of follow-up. Regarding left ventricular (LV) and RV systolic function, no statistical difference was found between before and after surgery in group 1. CONCLUSION: A high success rate of surgical correction of EbA, with an encouraging durability of the valve, was noted. Biventricular systolic function was maintained fairly in most patients with types A and B postoperatively. A late increase in RV systolic function after an initial reduction and unchanged LV systolic function were observed in the patients with types C and D postoperatively.

Effects of pre-operative oral carbohydrates on insulin resistance and postoperative recovery in diabetic patients undergoing coronary artery bypass grafting: study protocol for a prospective, single-blind, randomized controlled trial.

BACKGROUND: Preoperative carbohydrates (CHO) supplement has been widely investigated in nondiabetic patients undergoing a variety of surgeries. It has been proved that preoperative CHO could alleviate postoperative insulin resistance (IR) and improve patients' well-being in nondiabetic patients. However, it remains controversial whether preoperative CHO could yield similar effects in diabetic patients. Till now, seldom has the administration of preoperative CHO been investigated in diabetic patients and there are limited studies reporting IR and postoperative recovery of diabetic patients undergoing cardiac surgery. METHODS AND ANALYSIS: We present a prospective, single-center, single-blind, randomized, no-treatment controlled trial of preoperative CHO on diabetic patients undergoing off-pump coronary artery bypass grafting (OPCAB). A total of 62 patients will be enrolled and randomized to either Group CHO or Group control (CTRL). Patients in Group CHO will consume CHO fluid containing 50 g carbohydrates orally the evening before surgery (20:00-24:00) while their counterparts in Group CTRL will be fasted after 20:00 the evening before surgery. The primary endpoint is postoperative IR assessed via homeostasis model assessment (HOMA). The secondary endpoints are postoperative levels of potential mediators relating to IR including inflammatory factors and stress reaction characterized by serum cortisol. Exploratory endpoints are in-hospital clinical endpoints. Continuous variables will be compared by Student's t-test or Mann-Whitney U test. Categorical variables will be compared with χ2 test or Fisher's exact test. All tests in the present study are two-tailed and P<0.05 is considered statistically significant. All analyses will be performed with R 4.0.4. DISCUSSION: This is the first prospective randomized controlled trial of preoperative CHO in diabetic patients undergoing cardiac surgery, with the hypothesis that preoperative CHO could improve postoperative IR and promote postoperative recovery. The research may assist in improving the clinical outcomes of diabetic patients undergoing OPCAB. TRIAL REGISTRATION: The trial has been prospectively registered with ClinicalTrials.gov ( https://register. CLINICALTRIALS: gov ) and Chinese Clinical Trial Registry ( http://www.chictr.org.cn ). Registry number is NCT05540249 and ChiCTR2000029664 respectively. Registered on Sept. 14, 2022. CLINICAL TRIALS UNIT: Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.

Surgical treatment for primary mitral valve tumor: a 25-year single-center experience.

OBJECTIVE: Primary mitral valve (MV) tumor is a rare lesion, and to date, there have been few larger surgical series of MV tumors. We retrospectively analyzed 11 cases of primary MV tumors regarding clinical and pathological features, surgical procedure and long-term outcomes. METHODS: From November 1983 to December 2008, we operated on 11 patients (age 36.3 ± 17.7 years, weight 55.4 ± 11.2 kg) with primary MV tumors. Symptoms were cardiac in 8 cases (72.7%) and neurologic in 3 (26.3%). Surgical procedures included en bloc excision and MV repair in 8 cases and tumor resection and MV replacement in 3. No radiotherapy or chemotherapy was given to patients with malignant tumors. RESULTS: Pathological diagnosis was papillary fibroelastoma in 3 cases, myxoma in 3, lymphangioma in 1, lipoma in 1, hemangioma in 1 and sarcoma in 2. No early deaths or complications occurred. Late death occurred in 2 patients with sarcoma 1 year postoperatively. At the latest follow-up, with a maximum of 25 years (mean 10.6 ± 8.8), the 9 survivors were in New York Heart Association functional class I with normal MV function and no echocardiographic evidence of local recurrence. CONCLUSIONS: The majority of primary MV tumors are benign. They can cause cardiac or neurologic symptoms and should be excised as soon as a diagnosis is made. For benign tumors, valve-sparing resection and valve repair are often possible with excellent long-term outcomes. The prognosis of malignant MV tumors is poor.

Surgical management of double-orifice tricuspid valve.

BACKGROUND AND AIM OF THE STUDY: Double-orifice tricuspid valve (DOTV) is a very rare cardiac malformation. We sought to describe our experience with surgical management of this defect in three cases. MATERIAL AND METHODS: Between September 2008 and October 2010, three patients (one male, two females) with DOTV were treated at our institute. They were 62, 20, and 32 years of age, respectively. The diagnosis of DOTV was made during the operation for other congenital cardiac malformations including partial atrioventricular septum defect, tetralogy of Fallot, and Ebstein's anomaly. The DOTV was regurgitant in all (moderate in one case and mild in two cases) without stenosis. Surgical management included tricuspid valve annuloplasty in two cases and suture of the accessory orifice in one case. Associated malformations were simultaneously corrected. RESULTS: Echocardiography after the surgery revealed good coaptation of the tricuspid valve with trivial regurgitation and no tricuspid stenosis. No operative complication or late deaths occurred. All three patients were asymptomatic on follow-up. CONCLUSIONS: The occurrence of the DOTV is extremely rare and it is difficult to diagnose by echocardiography. It is always associated with other congenital cardiac malformations that determine patient outcome.

Repair of a ventricular septal defect in a patient with left lung agenesis.

Congenital heart disease combined with lung agenesis is extremely rare. We report a case of a 5-year-old female with a ventricular septal defect (VSD) and left lung agenesis with severe pulmonary hypertension who underwent successful closure of the VSD.

Surgical treatment of partial anomalous pulmonary venous connection misdiagnosed as atrial septal defect underwent transcatheter occlusion: A case report.

This case highlights the importance of coordinating with cardiopediatricians or congenitalists in the evaluation and treatment of ASD.

Zero→Two-Dimensional Metal Nanostructures: An Overview on Methods of Preparation, Characterization, Properties, and Applications.

Metal nanostructured materials, with many excellent and unique physical and mechanical properties compared to macroscopic bulk materials, have been widely used in the fields of electronics, bioimaging, sensing, photonics, biomimetic biology, information, and energy storage. It is worthy of noting that most of these applications require the use of nanostructured metals with specific controlled properties, which are significantly dependent on a series of physical parameters of its characteristic size, geometry, composition, and structure. Therefore, research on low-cost preparation of metal nanostructures and controlling of their characteristic sizes and geometric shapes are the keys to their development in different application fields. The preparation methods, physical and chemical properties, and application progress of metallic nanostructures are reviewed, and the methods for characterizing metal nanostructures are summarized. Finally, the future development of metallic nanostructure materials is explored.

Zwitterionic Hydrogel-Impregnated Membranes with Polyamide Skin Achieving Superior Water/Salt Separation Properties.

Support-free nonporous membranes have emerged as a new material platform for osmotic pressure-driven processes due to its insusceptibility to internal concentration polarization (ICP). Herein, we demonstrate high-performance membranes of zwitterionic hydrogels impregnated in porous membranes with a skin layer of highly cross-linked polyamides on both sides prepared by gel-liquid interfacial polymerization (GLIP). Such a configuration eliminates the pores and thus ICP, while the thin polyamide layer provides high salt rejection but negligible resistance to the water transport compared with the hydrogels. The polyamide skin layers are characterized using scanning electron microscopy and atomic force microscopy. The effect of the hydrogel compositions and polyamide formation conditions on the water/salt separation properties is thoroughly investigated. Example membranes show water permeance and salt rejection comparable to state-of-the-art commercial forward osmosis membranes and essentially no ICP.

Results of Left Ventricular Reconstruction With and Without Mitral Valve Surgery.

BACKGROUND: This study aims to compare the midterm outcomes of left ventricular reconstruction with those of left ventricular reconstruction plus mitral valve surgery in patients with left ventricular aneurysm due to anterior myocardial infarction and moderate mitral regurgitation. METHODS: A total of 523 patients (75 who underwent left ventricular reconstruction plus mitral valve surgery and 448 who underwent left ventricular reconstruction) with concomitant moderate mitral regurgitation were included in the study population. All-cause mortality was considered the primary endpoint. Major adverse cardiovascular and cerebrovascular events, including death, myocardial infarction, stroke, and subsequent mitral valve surgery, were considered secondary endpoints. Multivariable proportional hazards Cox regression models were used to assess the associations between groups and outcomes. In the sensitivity analysis we excluded patients who did not undergo coronary artery bypass graft and repeated the statistical analysis above. RESULTS: The median follow-up time among all patients was 41 months. There was no significant difference between the left ventricular reconstruction plus mitral valve surgery and the left ventricular reconstruction groups with regard to all-cause mortality (P = .208) and major adverse cardiovascular and cerebrovascular events (P = .817) after adjustment for covariates. In the sensitivity analysis there was no significant difference between the left ventricular reconstruction plus mitral valve surgery and left ventricular reconstruction groups with regard to all-cause mortality (P = .158) and major adverse cardiovascular and cerebrovascular events (P = .651) after adjustment for covariates. CONCLUSIONS: The clinical outcomes of left ventricular reconstruction are comparable with those of left ventricular reconstruction plus mitral valve surgery in patients with left aneurysm and moderate mitral regurgitation.

Diagnosis, operation, recurrence, metastasis, and death: a case of primary cardiac rhabdomyosarcoma.

We present a case report of a 48-year-old man with a huge left atrial rhabdomyosarcoma who presented as severe mitral stenosis and accepted emergency surgery. Two years later, a pathologic fracture revealed osseous metastasis, and intracardiac recurrence was detected by echocardiography. The patient died of multiple organ failure in the end. This case is an unusual presentation of complete course of cardiac rhabdomyosarcoma (CR) from diagnosis, operation, recurrence, and metastasis to death. Although primary CR is highly lethal, operation should be indicated to clarify the diagnosis, relieve symptoms, and improve short-term survival.

Outcomes of Ebstein's Anomaly Patients Treated with Tricuspid Valvuloplasty or Tricuspid Valve Replacement: Experience of a Single Center.

BACKGROUND: The incidence of Ebstein's anomaly is extremely low, and except for the Mayo Clinic, no cardiac center has reported on a sufficient number of patients. The aim of our study was to report the outcomes of Ebstein's anomaly patients treated with tricuspid valvuloplasty (TVP) or tricuspid valve replacement (TVR). METHODS: TVP or TVR was performed in 245 patients from July 2006 to April 2016. We reviewed patients' records and contacted patients via outpatient service and over the telephone. RESULTS: The mean follow-up time was 43.6 ± 32.6 months, and 224 (91.4%) patients underwent follow-up. The mean operative age was 31.2 ± 15.7 years. TVR was performed in 23 patients, and TVP was performed in 201 patients. The 30-day mortality rate was 1.3%, and the overall survival rate was 97.9% at 5 and 10 years. The early mortality rate of the TVP group was lower than that of the TVR group (0.5% vs. 8.7%, P = 0.028), and the overall mortality rate of the TVP group was lower than that of the TVR group, without statistical significance (1.0% vs. 8.7%). After propensity score matching, the rates of mortality and New York Heart Association class ≥ III were lower in the TVP group than those in the TVR group without statistical significance. Seven patients with Type B Wolff-Parkinson-White (WPW) syndrome underwent one-stage surgery, and arrhythmias disappeared. Six patients suffered from episodes of left ventricular outflow tract obstruction (LVOTO) during surgery. Severe LVOTO could be treated with reoperation of the atrialized right ventricle. CONCLUSIONS: Ebstein's anomaly patients treated with TVP or TVR can experience optimal outcomes with midterm follow-up. However, TVP should be the first-choice treatment. Optimal outcomes can be obtained from one-stage operation in patients with Type B WPW syndrome. Severe LVOTO during surgery might be related to improper operation of the atrialized right ventricle.

Congenital absence of anterior papillary muscle of the tricuspid valve and surgical repair with artificial chordae.

We report the case of a 26-year old woman who underwent successful tricuspid valve repair for the absence of the anterior papillary of the tricuspid valve. Preoperative echocardiography revealed grade IV tricuspid valve regurgitation, caused by congenital absence of the anterior papillary muscle and prolapse of the anterior leaflet. Tricuspid valve repair was performed using artificial chords consisting of two polytetrafluoroethylene sutures and a concomitant ring annuloplasty. Postoperative echocardiography revealed mild tricuspid valve regurgitation. This approach represented a safe and effective technique for tricuspid valve repair in congenital absence of papillary muscle.

A preoperative and intraoperative predictive model of prolonged intensive care unit stay for valvular surgery.

BACKGROUND AND AIM OF THE STUDY: In developing countries, the costs of intensive care unit (ICU) stay are very high for patients after valve surgery. In addition, patients with a prolonged ICU stay have a poor prognosis compared to those with a short ICU stay. The study aim was to develop a specific risk model and to use a logistic EuroSCORE model to predict prolonged ICU stay after valve surgery. METHODS: A total of 507 consecutive patients undergoing valve surgery were studied using univariate and multivariate analyses. Prolonged ICU stay was defined as five days or more. Stepwise logistic regression analysis was used to identify the risk factors for prolonged ICU stay. These variables were then used to calculate a prognostic score (S) and a predicted probability (P) for prolonged ICU stay. A receiver operating characteristic (ROC) curve was calculated to measure the prognostic value of the new risk model and logistic EuroSCORE model. Sensitivity and specificity analysis were used for evaluation. RESULTS: Multivariate logistic regression analysis showed that age > or = 65 years, left ventricular ejection fraction (LVEF) < or = 50%, cardiothoracic ratio (CTR) > or = 0.68, previous cardiac surgery, maximal voluntary ventilation (MVV) observed/predicted < 71% and repeat cardiopulmonary bypass (CPB) during surgery were risk factors. Mitral valve surgery reduced the risk of prolonged ICU stay. Observed probabilities compared well with predicted probabilities. The ROC curve produced an area under the curve (AUC) value of 0.81 for prolonged ICU stay. Based on predicted probability, patients were classified as low-risk (0 < or = P < 10%), intermediate-risk (10% < or = P < 20%), high-risk (20% < or = P < 40%) and very high-risk (> or = 40%) groups. A P-value > or = 40% was used as a cut-off point for the prognostic test. The specificity of this test was 97%, sensitivity 32%, positive predictive value 62%, negative predictive value 89%, positive likelihood ratio 10.67, and negative likelihood ratio 0.70. The ROC curve of a logistic EuroSCORE model gave an AUC value of 0.66 for prolonged ICU stay. CONCLUSION: The study results showed that individual patients undergoing valve surgery could be stratified according to their risk factors for prolonged ICU stay. High-risk patients may require more careful preoperative and postoperative management to reduce postoperative mortality, morbidity, the length of ICU stay, and therefore the cost of valve surgery.

[Surgical treatment of giant coronary artery aneurysm].

OBJECTIVE: To discuss the clinical features and surgical treatments of giant coronary artery aneurysm (CAA). METHODS: From July 1996 to October 2004, 6 giant CAA patients were underwent surgery at Fuwai hospital. Three cases were underwent CAA resection, 2 concomitant coronary bypass, 3 reconstruction. The giant CAA was often combined with other cardiac diseases. Four cases underwent additional procedures of fistula closure, 3 aortic valve replacements, 2 aortoplasty and 1 thrombus cleaning at the same time. RESULTS: All patients recovered uneventfully. The mean of cardiopulmonary bypass time was (144 +/- 26) min (range 67 to 207 min). Aortic cross clamping time was (104 +/- 21) min (range 56 to 172 min). Patients follow-up time occurred from 8 to 87 months (mean of 48 months). All patients were free of symptoms during follow-up. None of the patients died during the follow-up period and none of the CAA recurred. CONCLUSIONS: The giant CAA is a serious cardiovascular disease, early diagnosis and surgical treatment are mandatory.

Genomic Instability Is Induced by Persistent Proliferation of Cells Undergoing Epithelial-to-Mesenchymal Transition.

TGF-ß secreted by tumor stroma induces epithelial-to-mesenchymal transition (EMT) in cancer cells, a reversible phenotype linked to cancer progression and drug resistance. However, exposure to stromal signals may also lead to heritable changes in cancer cells, which are poorly understood. We show that epithelial cells failing to undergo proliferation arrest during TGF-ß-induced EMT sustain mitotic abnormalities due to failed cytokinesis, resulting in aneuploidy. This genomic instability is associated with the suppression of multiple nuclear envelope proteins implicated in mitotic regulation and is phenocopied by modulating the expression of LaminB1. While TGF-ß-induced mitotic defects in proliferating cells are reversible upon its withdrawal, the acquired genomic abnormalities persist, leading to increased tumorigenic phenotypes. In metastatic breast cancer patients, increased mesenchymal marker expression within single circulating tumor cells is correlated with genomic instability. These observations identify a mechanism whereby microenvironment-derived signals trigger heritable genetic changes within cancer cells, contributing to tumor evolution.