From intermolecular interactions to structures and properties of a novel cocrystal explosive: a first-principles study.

By employing a first-principles method, we conducted a thorough study on a novel cocrystal explosive 1 : 1 NTO : TZTN and gained insight into the interaction-structure-property interrelationship. Mulliken bond orders, Hirshfeld surfaces, intermolecular binding energies, packing coefficients, and oxygen balance were calculated to analyze the intermolecular interactions and structures of the cocrystal explosive. The cocrystallization of NTO and TZTN molecules enhances the intermolecular binding force, which drives the synthesis of the cocrystal. However, the cocrystallization decreases the molecular packing density along the closest packed directions, which reduces the density by 10.5% and deteriorates the oxygen balance. All of these lead to a reduction in the detonation performance compared to NTO explosives. We have also proposed a new method to evaluate the impact sensitivity according to the lattice dynamics calculation. The cocrystal explosive has a lower impact sensitivity than TZTN but higher than NTO, which agrees well with experiments.

Combined treatment of ulinastatin and tranexamic acid provides beneficial effects by inhibiting inflammatory and fibrinolytic response in patients undergoing heart valve replacement surgery.

OBJECTIVE: To investigate the effect of ulinastatin and tranexamic acid administered alone or in combination on inflammatory cytokines and fibrinolytic system in patients undergoing heart valve replacement surgery during cardiopulmonary bypass (CPB). BACKGROUND: CPB-induced fibrinolytic hyperfunction and systemic inflammatory response syndrome (SIRS) are the leading causes responsible for the occurrence of postsurgical complications such as postsurgical cardiac insufficiency and lung injury, which may lead to an increase in postsurgical bleeding, prolongation of hospital stay, and increased costs. METHODS: One hundred twenty patients undergoing heart valve replacement surgery during CPB were randomly assigned into 4 groups of 30 patients each: blank control group (Group C), tranexamic acid group (Group T), ulinastatin group (Group U), and tranexamic acid-ulinastatin combination group (Group D). Physiological saline, tranexamic acid, ulinastatin, and a combination of tranexamic acid and ulinastatin were given to each group, respectively. Arterial blood was collected from the radial artery at 4 time points: after induction of anesthesia (T1), unclamping the ascending aorta (T2), and at 1 hour (T3) and 24 hours (T4) after CPB. The levels of plasma tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), neutrophil elastase (NE), and the concentrations of tissue plasminogen activator (t-PA) and α2-antiplasmin (α2-AP) were detected. The changes in the volume of pericardial mediastinal drainage after surgery were observed and recorded. RESULTS: The plasma TNF-α, IL-6, and NE levels significantly increased in patients from all 4 groups at time points of T2, T3, and T4 in comparison to those before CPB (P < .05), and the plasma TNF-α and IL-6 levels in groups U and D were significantly lower than those in the other 2 groups (P < .05). The plasma t-PA, α2-AP, and D-dimer concentrations significantly increased in patients from all 4 groups at T2 and T3 compared with those before CPB (P < .05), and the plasma t-PA and D-dimer concentrations were significantly lower in groups T and D than those in groups U and C (P < .05) at T2 and T3. The plasma α2-AP concentrations in groups T and D were significantly higher than those in Group C at T3 (P < .05). The volumes of pericardial mediastinal drainage per body surface area were significantly lower in groups T and D than those in Group C 6 hours after the surgery (P < .05). CONCLUSIONS: Ulinastatin inhibits the release of inflammatory medium and reduces the inflammatory response during CPB. Tranexamic acid can effectively inhibit the fibrinolytic hyperfunction caused by CPB and thus decreases postsurgical bleeding. In addition, it exhibits a minor anti-inflammatory response. As a consequence, a combined treatment of ulinastatin and tranexamic acid reduces postsurgical bleeding and shortens postoperative hospital stay in patients undergoing heart valve replacement surgery.

Auricular bean embedding improves urination in epidural labor analgesia: A single center randomized controlled study.

BACKGROUND: Acupoint buried beans on the auricle is a feasible method to prevent and treat postpartum urinary retention. OBJECTIVE: This study investigated the effect of auricular acupoint buried beans on postpartum urination and maternal and fetal outcomes following epidural analgesia for labor. METHODS: Two hundred forty primiparas underwent vaginal trial labor analgesia from May 2020 to January 2021 and were randomly placed into the intervention and control groups. Both groups received epidural labor analgesia. Maternal urination during labor, 2 h postpartum, and the time for first postpartum urination were recorded as primary outcomes, with maternal and infant outcomes documented as secondary results. Statistical analysis was performed using the independent sample t-test, non-parametric rank-sum, or chi-square test using the SPSS Statistics 25.0 software. RESULTS: Two hundred eight study participants were subsequently included in the results, i.e., 105 patients in the intervention group and 103 in the control group. The intervention group comprised a significantly lower number of patients with excessive residual urine volume at cervical dilatation of 5-6 cm (P< 0.05). The total postpartum score of the intervention group was lower than in the control group (P< 0.01), and the time to first urination was shorter compared with the control group (P< 0.05). In the intervention group, the time of labor analgesia, the duration of the first stage of labor, and the total labor time were shorter compared with the control group (P< 0.01). CONCLUSION: Auricular acupoint embedded beans can improve the urination status at cervical dilatation of 5-6 cm and 2 h postpartum, as well as significantly shorten the duration of labor.

[Acute kidney injury early after cardiac surgery with cardiopulmonary bypass: clinical analysis].

OBJECTIVE: To explore the occurrence of acute kidney injury (AKI) in early stage after cardiac surgery under cardiopulmonary bypass (CPB) and discuss the perioperative risk factors and its impact on clinical outcome. METHODS: Retrospective analysis was performed among 1472 adult patients undergoing cardiac surgery with CPB between January 2008 and April 2011. The postoperative occurrence of AKI following cardiac surgery was stratified according to the RIFLE criteria. And the perioperative risk factors of AKI and its impact on clinical outcome were analyzed. RESULTS: AKI occurred in 437 patients (29.7%) within 72 hours postoperation. Of these, 292 (19.8%) fulfilled AKI-Risk, 110 (7.5%) AKI-Injury and 35 (2.4%) AKI-Failure. Logistic regression analysis showed that age, hypertension, chronic renal insufficiency, reoperation, aortic surgery, CPB duration, intraoperative transfused erythrocyte volume and perioperative use of intra-aortic balloon pump were independent risk factors for AKI. A postoperative elevation of AKI level was associated with a prolonged duration of mechanical ventilation, intensive care unit stay, postoperative hospital stay, delayed extubation, extubation failure and death. Receiver operator characteristic (ROC) curve showed that AKI classification was a postoperative predictor of delayed extubation, extubation failure and death. CONCLUSION: As a common complication after cardiac surgery, AKI is associated with many perioperative risk factors. And the AKI classification is predicator of delayed extubation, extubation failure and death.

SERPINE1 Gene Is a Reliable Molecular Marker for the Early Diagnosis of Aortic Dissection.

With the acceleration of population aging, the detection rate of aortic dissection has increased. The incidence rate of aortic dissection has increased year by year and has become a serious threat to human health. However, the current clinical treatment of aortic dissection is mainly limited to surgery (including intracavity), but the complexity of the disease and the high risk of surgery seriously affect the overall treatment effect of the disease. Therefore, an in-depth study of the pathogenesis of aortic dissection and the development of early diagnosis methods is not only expected to control the development of aortic dissection but also to improve the existing clinical treatment effect. Based on the bioinformatics analysis of the related mRNA sequence data of aortic dissection in GEO database, the gene expression regulatory network of aortic dissection was constructed. Through the screening of key node genes, the key factors (molecular markers) that may affect the occurrence of aortic dissection were obtained, and their functions were tested in human aortic smooth muscle cells (HAoSMC). Finally, it was concluded that SERPINE1 gene is a reliable molecular marker for the early diagnosis of aortic dissection.

Transcriptomic responses of Saccharum spontaneum roots in response to polyethylene glycol - 6000 stimulated drought stress.

Drought is the abiotic factor that adversely affects plant growth, development survival, and crop productivity, posing a substantial threat to sustainable agriculture worldwide, especially in warm and dry areas. However, the extent of damage depends upon the crop growth stage, severity and frequency of the stress. In general, the reproductive growth phase is more sensitive to stresses causing a substantial loss in crop productivity. Saccharum spontaneum (L.) is the most variable wild relative of sugarcane with potential for use in sugarcane crop improvement programs. In the present study addresses the transcriptomic analysis of drought stress imposed by polyethylene glycol-6000 (PED-6000; w/v- 25%) on the root tip tissues of S. spontaneum GX83-10. The analysis of microarrays of drought-stressed roots was performed at 0 (CK), 2 (T2), 4 (T4), 8 (T8) and 24 h (T24). The analyzed data were compared with the gene function annotations of four major databases, such as Nr, KOG/COG, Swiss-Prot, and KEGG, and a total of 62,988 single-gene information was obtained. The differently expressed genes of 56237 (T4), 59319 (T8), and 58583 (T24), among which CK obtained the most significant number of expressed genes (35920) as compared to T24, with a total of 53683 trend genes. Gene ontology (GO) and KEGG analysis were performed on the 6 important trends, and a total of 598 significant GO IDs and 42 significantly enriched metabolic pathways. Furthermore, these findings also aid in the selection of novel genes and promoters that can be used to potentially produce crop plants with enhanced stress resistance efficiency for sustainable agriculture.

Effect of subzero-balanced ultrafiltration on lung gas exchange capacity after cardiopulmonary bypass in adult patients with heart valve disease.

OBJECTIVES: This study was conducted to evaluate the effect of a new ultrafiltration technique--the subzero-balanced ultrafiltration (SBUF)--on lung gas exchange capacity after cardiopulmonary bypass (CPB) in adult patients with heart valve disease. BACKGROUND: Attenuation of lung gas exchange capacity is one of the most common manifestations of an inflammatory response after CPB. METHODS: Ninety-four patients who required CPB for cardiac surgery were randomized into 2 groups according to whether they received SBUF. Gas exchange capacity expressed as the oxygen index (OI), the respiratory index (RI), and the alveolar-arterial oxygen pressure difference (P(A-a)O2) were measured after intubation (T1), at the termination of CPB (T2), on admission to the intensive care unit (ICU) (T3), at postoperative hour 6 (T4), and at postoperative hour 12 (T5). RESULTS: There were no significant differences in gas exchange capacity between the 2 groups at T1, T4, and T5. CPB produced significant changes in OI, RI, and P(A-a)O2 in the control group, whereas these changes were not significantly different in the study group. The OI in the study group was significantly higher at T2, and RI and P(A-a)O2 were significantly lower at T2 and T3. In the study group, the intubation time was shorter, and the transfusion volume within 24 hours postoperatively was less. The 2 groups were comparable with respect to the incidence of respiratory complications, length of stay in the ICU, duration of hospital stay, need for infusions of inotropic agents, and drainage volumes within 24 hours postoperatively. CONCLUSIONS: SBUF during CPB can produce an immediate improvement in lung gas exchange capacity, which may effectively minimize pulmonary dysfunction in adult patients undergoing cardiac surgery.

[Prosthesis-patient mismatch in the mitral valve position: the initial result of a single-institutional observational study in China].

OBJECTIVE: To analysis the causes of valve prosthesis-patient mismatch (PPM) after mitral valve replacement in Chinese patients. METHODS: Consecutive 100 patients for elective mitral valve replacement from January 2009 to June 2009 were enrolled and followed for this study. There were 37 males and 63 females. The mean age at operation was (52 ± 9) years (ranging 32 to 76 years). The predominant mitral valve lesion was stenosis in 60 patients, regurgitation in 14 patients and mixed in 26 patients. Among them, 63 patients were combined tricuspid valve regurgitation. Mitral valve effective orifice area was measured by Doppler echocardiography in 100 patients who received mitral valve replacement and indexed for body surface area (EOAI). PPM was defined as not clinically significant if the EOAI was above 1.2 cm(2)/m(2), as moderate if it was >0.9 and ≤ 1.2 cm(2)/m(2), and as severe if it was ≤ 0.9 cm(2)/m(2). By using the criteria, all 100 patients were classified to two groups: PPM group and no PPM group. The clinical characteristic of the patients between the two groups was compared to determine the causes of PPM and the predictors of outcomes after mitral valve replacement, such as the gender, age, valve prosthesis type, size, body surface area, and mitral valve lesion, et al. RESULTS: Of the 100 patients after MVR, 52 (52.0%) had significant PPM, 51 (51.0%) had moderate PPM, and 1 (1.0%) had severe PPM. In comparison to patients in no PPM group, patients in PPM group had a significantly larger body surface area [(1.76 ± 0.17) m(2) vs. (1.59 ± 0.13) m(2), P < 0.01] and higher prevalence of male gender (55.8% vs. 16.6%, P < 0.01). The other preoperative and operative data were similar in both groups, such as the valve prosthesis type, size, and mitral valve lesion, et al. There were no significant differences in postoperative Doppler-echocardiographic data of cardiac structure and heart function between the two groups (P > 0.05). CONCLUSIONS: The higher incidence of PPM in mitral valve position was in male or large body surface area patients. At the time of operation, surgeons should consider the related factors, such as the patient's gender and body surface area, et al. A larger prosthesis size might be implanted to avoid PPM in mitral valve position.

[The empirical study on paracrine communication of bone marrow mesenchymal stem cells].

OBJECTIVE: To study the influence of (60)Co gamma exposure on paracrine effect of marrow mesenchymal stem cells (MSC). To evaluate the function and construction after early stage of acute myocardial infarction (AMI) by injection of supernatant liquid. To discuss the mechanism of prarcrine communication initially. METHODS: MSC were radiated by (60)Co gamma with different dosage. The culture solution was collected peri-irradiation. The changes of Vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), Interleuki-1beta (IL-1beta) in supernatant liquid were checked by ELISA. Using a rat model of AMI, the supernatant liquid and control medium were injected intramyocardially and intraperitoneally according to the project. After 4 weeks, the cardiac dimension and functions were assessed, the microvessel density were detected. RESULTS: Three cytokines decreased significantly after irradiation, with the increasing in dosage of irradiation, the secretory volume of cytokines decreased greatly. When compared with the control group (group A 6.6 +/- 0.6) and medium group (group C 5.7 +/- 0.7), the microvessel density in supernatant liquid group (group B 10.8 +/- 2.9) increased obviously, contributing to improvement in cardiac function and dimension. (Left ventricular internal dimension in diastolic (LVDd) postoperation: A 8.1 mm +/- 1.5 mm, B 7.0 mm +/- 1.5 mm, C 7.7 mm +/- 1.1 mm; Eject fraction (EF) postoperation: A 43.8% +/- 8.9%, B 51.5% +/- 7.8%, C 45.6% +/- 8.1%. CONCLUSIONS: (60)Co gamma radiation exposure can degrade MSC' ability of paracrine communication. The paracrine effect which should take important role in improving the cardiac function after AMI. The mechanism of prarcrine is complex, neovascularization is the important link.

[Clinical analyses of cardiovascular operations in patients with severe dilated left ventricle].

OBJECTIVE: To explore the perioperative features of surgical treatment in valvular patients with severe dilated left ventricle and investigate the structural changes of left ventricle and its correlation with cardiac functions. METHODS: A total of 126 patients with severe dilated left ventricle underwent mitral valve and/or aortic valve operation from January 2003 to December 2008, including mitral valve replacement (MVR) (n = 27), mitral valvuloplasty (MVP) (n = 13), aortic valve replacement (AVR) (n = 51), AVR+MVR (n = 25) and AVR + MVP (n = 10). There were 79 males and 47 females with a mean age of (52 ± 13) years old. The mean pathological course was (18 ± 12) years. The pathological changes were mainly of aortic and/or mitral incompetence. The concomitant procedures included Bentall procedure (n = 6), coronary artery bypass grafting (n = 3), tricuspid valvuloplasty (n = 58) and left atrial folding (n = 62). RESULTS: The perioperative mortality was 3.17% (4/126). Two died of multiple organ failure (MOF) secondarily to severe low-output syndrome while another 2 died of sudden ventricular fibrillation. Forty-six (36.5%) patients suffered from ventricular arrhythmia during the earlier postoperative period and they required a venous injection of lidocaine and/or amiodarone. Fourteen (11.1%) patients suffered from severe low-output syndrome. Among them, 4 patients were resuscitated with an intra-aortic balloon pump for another 4 - 6 days. And 26 (20.6%) cases were complicated with multiple organ failure. The echocardiographic examinations showed that left ventricular dimensions decreased significantly at Days 7 - 14 postoperatively and progressively at Months 6 - 12 postoperatively. Left ventricular end-diastolic diameter (LVEDD) was (77 ± 6) mm preoperatively and (63 ± 12) mm (Days 7 - 14), (58 ± 10) mm (Months 6 - 12) postoperatively (P < 0.01). The contractile function of left ventricle temporarily decreased during the early postoperative stage and improved gradually afterwards. But it was not restored to normal range even until 6 - 12 m post-operation. Ejection fraction was 49% ± 12% preoperatively and 42% ± 9% (Days 7 - 14), 51% ± 7% (Months 6 - 12) postoperatively (P < 0.01). Left ventricular fraction shortness was 28% ± 7% preoperatively and 25% ± 4% (Days 7 - 14), 29% ± 5% (Months 6 - 12) postoperatively (P < 0.05). CONCLUSION: For the patients with severe dilated left ventricle, cardiovascular operation can achieve an excellent outcome through a rigorous perioperative regiment. The prevention and treatment of postoperative ventricular arrhythmia should be emphasized. The dimension of left ventricle decreases progressively during the early postoperative period. There is a postoperative decline of cardiac functions.

[Surgical treatment of isolated right-sided infective endocarditis].

OBJECTIVE: To analyze the surgical treatment and outcomes of isolated right-sided infective endocarditis. METHODS: From January 1994 to February 2009, 28 patients with isolated right-sided infective endocarditis underwent operation whose clinical data was retrospectively reviewed. There were 18 male and 10 female, age ranged from 10 to 72 years with a mean of 38 years. All of the patients presented intermittent fever, 14 patients presented heart failure (NYHA class III or IV), 25 patients had a history of pulmonary embolism or pneumonia, 18 patients had positive culture; 27 patients had intra-cardiac vegetations confirmed by echocardiogram. All the operations were performed under cardiopulmonary bypass. Antibiotic therapy continued for another 2 to 3 weeks after surgery. RESULTS: One patient had underwent re-operation due to mediastinal bleeding, 2 patients needed mechanical ventilation for more than 1 week after surgery, renal dysfunction occurred in 3 patients. After surgery, 11 patients presented with mild or moderate tricuspid regurgitation before discharge. One patient (3.6%) died in hospital after surgery due to severe infection and multi-organ failure, the other 27 patients were cured and discharged. Patients were followed up for 6 months to 15 years.NYHA class decreased in all patients, and the symptoms of heart failure improved significantly after surgery. No recurrent case was found. CONCLUSIONS: Surgery is an effective treatment for isolated right-sided infective endocarditis with congenital heart disease or right heart implants. Good outcomes are observed in these settings.

[Analysis on the risk factors of intracardial thrombus after prosthetic valve replacement: a 1-year follow-up study].

OBJECTIVE: To analysis the risk factors predicting intracardial thrombus after prosthetic valve replacement. METHODS: The clinical data of 29 cases from January 2005 to April 2009 with intracardial thrombus after prosthetic valve replacement during a 1-year follow-up was retrospectively analyzed. There were 11 male and 18 female, aged from 12 to 70 years with a mean of 48 years. The risk factors of intracardial thrombus were examined by univariate and multivariate analysis. RESULTS: Univariate analysis found that bioprosthetic valve replacement, anticoagulation using aspirin, valve replacement at mitral position, atrial fibrillation, preoperative and postoperative internal diameter of left atrium, postoperative fibrinogen were predict factors of intracardial thrombus after prosthetic valve replacement (P < 0.05). Logistic regression analysis showed valve replacement at mitral position (OR = 9.815, P < 0.05), atrial fibrillation (OR = 5.267, P < 0.05), preoperative internal diameter of left atrium (OR = 4.529, P < 0.05) were significant risk factors of intracardial thrombus after prosthetic valve replacement. CONCLUSIONS: Valve replacement at mitral position, atrial fibrillation, and preoperative internal diameter of left atrium are the correlated risk factors of intracardial thrombus after prosthetic valve replacement. Anticoagulation after prosthetic valve (especially bioprosthetic valve) replacement should be standardized to prevent intracardial thrombus formation.

Short-term and mid-term effects of radiofrequency ablation in mitral valve surgery in patients with different left atrial sizes.

BACKGROUND: To evaluate the efficacy of atrial fibrillation radiofrequency ablation (AFRA) in patients with chronic valvular atrial fibrillation (AF) with different left atrial sizes [left atrial diameter (LAD) >45 or ≤45 mm]. METHODS: Between May 2016 and January 2019, 264 patients who underwent cardiac operations with modified bipolar AFRA in the Department of Cardiovascular Surgery, PLA General Hospital, were enrolled. The clinical data of the patients were analysed, and inclusion and exclusion criteria were implemented. A propensity score was given for two groups of different left atrial sizes: group A (75 patients with LAD >45 mm) and group B (75 patients with LAD ≤45 mm). Preoperative general data, operative indicators, postoperative mortality, complications, and sinus rhythm recovery were analysed and compared between the two groups. RESULTS: The rates of sinus rhythm recovery in group A (LAD >45 mm) at 1 week, 6 months, 1 year, and 2 years after surgery were 84.0%, 81.33%, 73.33%, and 69.33%, respectively, compared with 90.67.0%, 88.00%, 86.67%, and 84.00% at 1 week, 6 months, 1 year, and 2 years after surgery, respectively, in group B (LAD ≤45 mm). The difference between the two groups was statistically significant at the two points in time of 1 year, and 2 years (P<0.05). Warfarin anticoagulation, the standard therapy, was applied after surgery. No new cerebrovascular events occurred in either group during short- and medium-term postoperative follow-up. CONCLUSIONS: Mitral valve surgery using improved Cox-Maze IV bipolar radiofrequency ablation was effective in treating chronic long-term persistent valvular AF and had an excellent sinus rhythm recovery rate. However, the larger the LAD, the less likely a patient was to maintain sinus rhythm as time passed after surgery.

[The empirical study in transplantation of bone marrow mesenchymal stem cells for acute myocardial infarction].

OBJECTIVE: To study the effect of (60)Co gamma ray on proliferation and differentiation potency of MSC. To evaluate the function of heart after early stage of acute myocardial infarction (AMI) in rats by transplantation of MSC. METHODS: Irradiated MSC was cultured with the method of adherent culture, the ability of its proliferation was detected by Methyl thiazolyl tetrazolium (MTT) shade selection test. The express of Cardiac troponin T (C-TNT) and beta-myosin heavy chain (beta-MHC) in MSC were detected by Reverse transcriptase-polymerase chain reaction (RT-PCR), which was induced by 5-azacytidine. Using a rat model of AMI, irradiated and unirradiated MSC were transplanted into myocardium after infarction. At 4 weeks, the cardiac dimension and functions were assessed by echocardiography and hemodynamics, the microvessel density were detected after VIII factor immunohistochemistry stain. RESULTS: The ability of proliferation in 4Gy group was depressed. C-TNT and beta-MHC expressed somewhat in unirradiated group. When compared with the control group (6.6 +/- 0.6), the microvessel density in both transplanted groups (12.7 +/- 2.2, 11.5 +/- 2.1) increased, contributing to improvement in cardiac function and dimension. CONCLUSION: MSC with or without differentiation potency can improve cardiac function equally at the early stage of AMI.

[Structural and functional changes of postoperative small left ventricle patients].

OBJECTIVE: To explore the perioperative features of surgical treatment in valvular patients with small left ventricle, and investigate the postoperative early structural changes of left ventricle and its correlation with cardiac function. METHODS: A total of 51 patients with small left ventricle underwent mitral valve replacement from January 2003 to August 2008. There were 7 males and 44 females with mean age of (48 +/- 5) years old. The mean pathologic course was (18 +/- 9) years old. The concomitant procedures included aortic valve replacement in 6 cases, coronary artery bypass grafting in 1 case, tricuspid valvular plasty in 48 cases, left atrial thrombi scavenging in 36 cases, and left atrium folding in 42 cases. RESULTS: The perioperative mortality was 3.9% (2/51). Fourteen patients (27.5%) suffered from severe low-output syndrome in the earlier period postoperatively. Among them, 5 patients needed secondary cardiopulmonary bypass (CPB) to assist circulation, with the result of 1 patient died of weaning off CPB unsuccessfully, 1 patient revived with intra-aortic balloon pump assisted for another 2 d after termination of CPB and another 1 patient died of multiple organ failure (MOF) 10 d later. Eleven cases complicated with MOF. Five patients complicated with ventricular arrhythmia. The echocardiographic examinations showed that the left ventricular dimensions didn't expand significantly postoperatively at 7 to 14 d postoperatively. Left ventricular end-diastolic diameter (LVEDD) was (36.5 +/- 3.2) mm preoperatively and (38.6 +/- 5.3) mm postoperatively (P > 0.05). Preoperative LVEDD index (LVEDDI) was (45.9 +/- 3.8) ml/m(2) and postoperative LVEDDI was (48.2 +/- 7.4) ml/m(2) (P > 0.05). The contract function of left ventricle was improved postoperatively but with no statistical significance. Ejection fraction was 48.6% +/- 6.7% preoperatively and 52.8% +/- 8.3% postoperatively. Left ventricular fraction shortness was 25.5% +/- 3.3% preoperatively and 27.1% +/- 1.3% postoperatively. CONCLUSIONS: For the patients with small left ventricle usually, the postoperative emphases should be put on the management of low output syndrome. The decreased dimension of left ventricle doesn't expand in the early period after valvular operation.

Revealing Solid Properties of High-energy-density Molecular Cocrystals from the Cooperation of Hydrogen Bonding and Molecular Polarizability.

In the domain of high-energy-density materials, the understanding to physico-chemical properties has long been primarily based on molecular structures whereas the crystal packing effect that significantly affects solid properties has been seldom involved. Herewith we predict the solid properties of six novel energetic cocrystals by taking into account of the crystal packing effect using a quantum chemistry method. We discover that the hydrogen bonding causes an increase in the molecular polarizability and their cooperation significantly changes the solid-state nature of the cocrystals compared to the pristine crystal and the gas counterparts. For example, stabilizing the multi-component molecular association by increasing the binding energy by 19-41% over the pristine crystals, improving the detonation performance by 5-10% and reducing the sensitivity to external stimuli compared to their pure crystal or gas counterparts. Therefore, the solid nature of the cocrystal is not a simple combination of the pure crystalline properties of its components and the heterogeneous molecular coupling effects must be considered to design improved functional cocrystals.

Stabilization of the Dual-Aromatic cyclo-N5- Anion by Acidic Entrapment.

Pentazole anion, the best candidate for full-nitrogen energetic materials, can be isolated only from acidic solution for unclear reasons, which hinders the high-yield realization of a full-nitrogen substance with higher energy density. Herein, we report for the first time the discovery of the dual aromaticity (π and σ) of cyclo-N5-, which makes the anion unstable in nature but confers additional stability in acidic surroundings. In addition to the usual π-aromaticity, similar to that of the prototypical benzene, five lone pairs are delocalized in the equatorial plane of cyclo-N5-, forming additional σ-aromaticity. It is the compatible coexistence of the inter-lone-pair repulsion and inter-lone-pair attraction within the σ-aromatic system that makes the naked cyclo-N5- highly reactive to electrophiles and easily broken. Only in sufficiently acid solution can the cyclo-N5- become unsusceptible to the electrophilic attack and gain extra stability through the formation of hydrogen-bonded complex from surrounding electrophiles; otherwise, the cyclo-N5- cannot be productively isolated. The dual aromaticity discovered in cyclo-N5- is expected to be universal for pnictogen five-membered ring systems.

Structural, mechanical properties, and vibrational spectra of LLM-105 under high pressures from a first-principles study.

In this work, we report the structure, mechanical properties, and vibrational spectra of 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105), an energetic molecular crystal, with a first-principles method based on density functional theory (DFT) using the recentely developped HASEM package. The elastic constants, acoustic velocity, and parameters of equations of state were calculated, and the predicted ordering of stiffness constants is C 33 (38.5 GPa) > C 11 (24.0 GPa) > C 22 (17.7 GPa). We also investigated the structure and equation of state of LLM-105 under hydrostatic pressure up to 100 GPa. The predicted structures are in good agreement with experimental results available from ambient pressure to 20 GPa. Under compressions, the LLM-105 crystal exhibits anisotropic compressibility, with a highly incompressible response along the a-axis and c-axis. It is worth noting that there is a sudden change in the lattice parameters and change rate of volume at ~30 GPa. Based on the intermolecular interaction analysis and vibrational spectra, a phase transition at the hydrostatic pressure of ~30 GPa is predicted.

[Mean flow of saphenous vein graft and its influencing factors in patients performed coronary artery bypass grafting].

OBJECTIVE: To analyze the mean blood flow of saphenous vein (SV) graft and it's influencing factors in off-pump coronary artery bypass grafting by using transit-time flowmeter (TTFM). METHODS: Three hundred and twenty-six patients were studied. After all anastomoses were completed, and hemo-dynamic status was stable, TTFM was utilized to measure and record the SV flow wave, pulsatility index (PI), value of mean flow, diastolic and systolic peak flow, vascular resistance, insufficiency ratio and mean blood pressure. The standard conditions of good graft status to define the normal mean flow included good diastolic augmentation of blood wave, PI less than 5, intraoperative and postoperative no significant change in electrocardiogram, and smoothly postoperative recovery. RESULTS: Total mean flow calculated from that of all patients was (39 +/- 23) ml/min (10-153 ml/min). Majority mean value (60.1%, 196/326) was in the range of 20-50 ml/min. Statistics showed that mean flow was significantly related to vascular resistance and diastolic peak flow and PI rather than the other factors (r was -0.95, 0.77 and -0.51 respectively). CONCLUSIONS: For the patients, over 15 ml/min mean flow of SV graft is acceptable, and over 35 ml/min is satisfactory. The diastolic peak flow and vascular resistance are two important factors influencing mean flow.