Chirality-selective topological magnon phase transition induced by interplay of anisotropic exchange interactions in honeycomb ferromagnet.

A variety of distinct anisotropic exchange interactions commonly exist in one magnetic material due to complex crystal, magnetic and orbital symmetries. Here we investigate the effects of multiple anisotropic exchange interactions on topological magnon in a honeycomb ferromagnet, and find a chirality-selective topological magnon phase transition induced by a complicated interplay of Dzyaloshinsky-Moriya interaction and pseudo-dipolar interaction, accompanied by the bulk gap close and reopen with chiral inversion. Moreover, this novel topological phase transition involves band inversion at high symmetry pointsKandK', which can be regarded as a pseudo-orbital reversal, i.e. magnon valley degree of freedom, implying a new manipulation corresponding to a sign change of the magnon thermal Hall conductivity. Indeed, it can be realized in 4dor 5dcorrelated materials with both spin-orbit coupling and orbital localized states, such as iridates and ruthenates,etc.This novel regulation may have potential applications on magnon devices and topological magnonics.

Electronic structures and quantum capacitance of twisted bilayer graphene with defects based on three-band tight-binding model.

Twisted bilayer graphene (tBLG) with C vacancies would greatly improve the density of states (DOS) around the Fermi level (EF) and quantum capacitance; however, the single-band tight-binding model only considering pz orbitals cannot accurately capture the low-energy physics of tBLG with C vacancies. In this work, a three-band tight-binding model containing three p orbitals of C atoms is proposed to explore the modulation mechanism of C vacancies on the DOS and quantum capacitance of tBLG. We first obtain the hopping integral parameters of the three-band tight-binding model, and then explore the electronic structures and the quantum capacitance of tBLG at a twisting angle of θ = 1.47° under different C vacancy concentrations. The impurity states contributed by C atoms with dangling bonds located around the EF and the interlayer hopping interaction could induce band splitting of the impurity states. Therefore, compared with the quantum capacitance of pristine tBLG (∼18.82 µF cm-2) at zero bias, the quantum capacitance is improved to ∼172.76 µF cm-2 at zero bias, and the working window with relatively large quantum capacitance in the low-voltage range is broadened in tBLG with C vacancies due to the enhanced DOS around the EF. Moreover, the quantum capacitance of tBLG is further increased at zero bias with an increase of the C vacancy concentration induced by more impurity states. These findings not only provide a suitable multi-band tight-binding model to describe tBLG with C vacancies but also offer theoretical insight for designing electrode candidates for low-power consumption devices with improved quantum capacitance.

High-temperature magnetically topological candidate material Mn3Bi2Te6.

The Mn-Bi-Te family displaying magnetism and non-trivial topological properties has received extensive attention. Here, we predict that the antiferromagnetic structure of Mn3Bi2Te6with three MnTe layers is energetically stable and the magnetic energy difference of Mn-Mn is enhanced four times compared with that in the single MnTe layer of MnBi2Te4. The predicted Néel transition point is raised to 102.5 K, surpassing the temperature of liquid nitrogen. The topological properties show that with the variation of the MnTe layer from a single layer to three layers, the system transforms from a non-trivial topological phase to a trivial topological phase. Interestingly, the ferromagnetic state of Mn3Bi2Te6is a topological semimetal and it exhibits a topological transition from trivial to non-trivial induced by the magnetic transition. Our results enrich the Mn-Bi-Te family system, offer a new platform for studying topological phase transitions, and pave a new way to improve the working temperature of magnetically topological devices.

Chiral charge density wave induced by mirror symmetry breaking in kagome metal.

Kagome lattice provides a distinctive platform to investigate various correlated electron orders. Recently, an unconventional charge density wave (CDW) with novel chirality is observed in the kagome metalAV3Sb5(A= K, Rb, Cs), and the origin of which is still unclear. Here, using a tight-binding model and the mean-field method, we calculate the electron order in the quasi-two-dimensional kagome lattice with 1/3 electron filling, and show that the chiral CDW emerges under a set of parameters withC6rotational symmetry but without mirror symmetry. Physically, the reason why we choose this set of parameters is based on the possible tangential distortion of the kagome lattice. Our results provide a fresh insight to understand the microscopic origin of the unconventional CDW inAV3Sb5.

Topological magnons in one-dimensional ferromagnetic Su-Schrieffer-Heeger model with anisotropic interaction.

Topological magnons in a one-dimensional (1D) ferromagnetic Su-Schrieffer-Heeger (SSH) model with anisotropic exchange interactions are investigated. Apart from the intercellular isotropic Heisenberg interaction, the intercellular anisotropic exchange interactions, i.e. Dzyaloshinskii-Moriya interaction and pseudo-dipolar interaction, also can induce the emergence of the non-trivial phase with two degenerate in-gap edge states separately localized at the two ends of the 1D chain, while the intracellular interactions instead unfavors the topological phase. The interplay among them has synergistic effects on the topological phase transition, very different from that in the two-dimensional (2D) ferromagnet. These results demonstrate that the 1D magnons possess rich topological phase diagrams distinctly different from the electronic version of the SSH model and even the 2D magnons. Due to the low dimensional structural characteristics of this 1D topological magnonic system, the magnonic crystals can be constructed from bottom to top, which has important potential applications in the design of novel magnonic devices.

Investigation on the interlayer coupling and bonding in layered nitride-halides ThNF and ThNCl.

Motivated by recent experimental observation [N. Z. Wang, et al., Inorg. Chem., 2019, 58, 9897], we investigated the electronic properties and chemical bonding in layered nitride-halide compounds ThNF and ThNCl using first-principles calculations to illustrate the interlayer interaction. The energy gaps and chemical valences of both compounds are in agreement with experimental data. The crystal orbital Hamiltonian population (COHP) and charge density differential analysis show that interlayer chemical bonding plays a more important role than that van der Waals interactions in ThNF and ThNCl, in contrast to isostructural ZrNCl and HfNCl. These results explain why it is difficult to intercalate ThNF and ThNCl with charged particles, as observed in experiments.

The use of intra-aortic balloon pump in patients undergoing heart valve replacement: outcome and risk analysis.

BACKGROUND AND AIM OF THE STUDY: Intra-aortic balloon pump (IABP) in heart valve surgical patients is associated with a higher mortality than coronary artery bypass grafting (CABG). The study aim was to analyze the early outcome of heart valve surgical patients requiring IABP support, and to assess the risk factors for early mortality. METHODS: Among a cohort of 5,786 patients undergoing heart valve replacement without CABG, 81 (1.4%) required IABP support. Data from these latter patients were collected and analyzed retrospectively, and univariate and multivariate logistic regression were applied to identify risk factors for early mortality in patients requiring IABP support. RESULTS: IABP was inserted in 30 patients intraoperatively, and in 51 patients postoperatively. The overall mortality was 50.6%. Mortality in the intraoperative IABP subgroup was significantly lower than in the postoperative IABP subgroup (26.7% versus 64.7%, p = 0.001). The independent risk factors for early mortality were: age increasing by 10 years (OR 1.906, 95% CI: 1.165-3.116, p = 0.010) and pulmonary hypertension (OR 4.153, 95% CI: 1.380-12.499, p = 0.011). Intraoperative IABP insertion (OR 0.297, 95% CI: 0.100-0.876, p = 0.028) was identified as a protective factor compared to postoperative insertion. CONCLUSION: The mortality of patients requiring IABP support after heart valve replacement was high. The efficacy of intraoperative IABP insertion was better than a postoperative mandatory use. Clearly, more attention should be paid to older patients or those with pulmonary hypertension, who may benefit less from IABP.

Reinforced aortic root reconstruction for acute type A aortic dissection involving the aortic root.

OBJECTIVE: There are debates regarding the optimal approach for AAAD involving the aortic root. We described a modified reinforced aortic root reconstruction approach for treating AAAD involving the aortic root. METHODS: A total of 161 patients with AAAD involving the aortic root were treated by our modified reinforced aortic root reconstruction approach from January 1998 to December 2008. Key features of our modified approach were placement of an autologous pericardial patch in the false lumen, lining of the sinotubular junction lumen with a polyester vascular ring, and wrapping of the vessel with Teflon strips. Outcome measures included post-operative mortality, survival, complications, and level of aortic regurgitation. RESULTS: A total of 161 patients were included in the study (mean age: 43.3 1 15.5 years). The mean duration of follow-up was 5.1 1 2.96 years (2-12 years). A total of 10 (6.2%) and 11 (6.8%) patients died during hospitalization and during follow-up, respectively. Thirty-one (19.3%) patients experienced postoperative complications. The 1-, 3-, 5-, and 10-year survival rates were 99.3%, 98%, 93.8%, and 75.5%, respectively. There were no instances of recurrent aortic dissection, aortic aneurysm, or pseudoaneurysm during the entire study period. The severity of aortic regurgitation dramatically decreased immediately after surgery (from 28.6% to 0% grade 3-4) and thereafter slightly increased (from 0% to 7.2% at 5 years and 9.1% at 10 years). CONCLUSION: This modified reinforced aortic root reconstruction was feasible, safe and durable/effective, as indicated by its low mortality, low postoperative complications and high survival rate.

Reinforced aortic root reconstruction for acute type A aortic dissection involving the aortic root / Reconstrução da raiz da aorta reforçada para dissecção aguda da aorta tipo A envolvendo a raiz da aórtica

OBJECTIVE: There are debates regarding the optimal approach for AAAD involving the aortic root. We described a modified reinforced aortic root reconstruction approach for treating AAAD involving the aortic root. METHODS: A total of 161 patients with AAAD involving the aortic root were treated by our modified reinforced aortic root reconstruction approach from January 1998 to December 2008. Key features of our modified approach were placement of an autologous pericardial patch in the false lumen, lining of the sinotubular junction lumen with a polyester vascular ring, and wrapping of the vessel with Teflon strips. Outcome measures included post-operative mortality, survival, complications, and level of aortic regurgitation. RESULTS: A total of 161 patients were included in the study (mean age: 43.3 1 15.5 years). The mean duration of follow-up was 5.1 1 2.96 years (2-12 years). A total of 10 (6.2%) and 11 (6.8%) patients died during hospitalization and during follow-up, respectively. Thirty-one (19.3%) patients experienced postoperative complications. The 1-, 3-, 5-, and 10-year survival rates were 99.3%, 98%, 93.8%, and 75.5%, respectively. There were no instances of recurrent aortic dissection, aortic aneurysm, or pseudoaneurysm during the entire study period. The severity of aortic regurgitation dramatically decreased immediately after surgery (from 28.6% to 0% grade 3-4) and thereafter slightly increased (from 0% to 7.2% at 5 years and 9.1% at 10 years). CONCLUSION: This modified reinforced aortic root reconstruction was feasible, safe and durable/effective, as indicated by its low mortality, low postoperative complications and high survival rate.

OBJETIVO: Há um debate sobre a melhor abordagem para dissecção aguda da aorta tipo A (DAAA) envolvendo a raiz da aorta. Nós descrevemos abordagem aórtica reforçada modificada de reconstrução de raiz para o tratamento DAAA envolvendo a raiz da aorta. MÉTODOS: Um total de 161 pacientes com DAAA envolvendo a raiz da aorta foram tratados pelo nosso abordagem reforçada modificada da reconstrução da raiz da aorta de janeiro de 1998 a dezembro de 2008. As características-chave da nossa abordagem modificada foram a colocação de um remendo de pericárdio autólogo na falsa luz, forro do lúmen supravalvar com um anel vascular, poliéster e envolvimento dos vasos com tiras de teflon. A avaliação pós-operatória incluiu mortalidade, sobrevivência, complicações, e grau de insuficiência aórtica. RESULTADOS: Um total de 161 pacientes foram incluídos no estudo (média de idade: 43,3 1 15,5 anos). A duração média de acompanhamento foi de 5,1 1 2,96 anos (2-12 anos). Um total de 10 (6,2%) e 11 (6,8%) pacientes morreram durante a internação e durante o acompanhamento, respectivamente. Trinta e um (19,3%) pacientes apresentaram complicações pós-operatórias. A 1 -, 3 -, 5 -, e as taxas de sobrevivência de 10 anos foram 99,3%, 98%, 93,8% e 75,5%, respectivamente. Não houve casos de dissecção aórtica recorrente, aneurisma ou pseudoaneurisma da aorta durante o período de estudo. A gravidade da regurgitação aórtica diminuiu drasticamente logo após a cirurgia (de 28,6% para grau 0 de 3-4%) e, posteriormente, teve ligeiro aumento (de 0% a 7,2% em 5 anos e de 9,1% aos 10 anos). CONCLUSÃO: A reconstrução da raiz da aorta reforçada modificada é viável, segura e durável/eficaz, como indicado pelas baixas mortalidade e complicações pós-operatórias e taxa de sobrevivência elevada.

Band filling and correlation controlling electronic properties and magnetism in K(x)Fe(2-y)Se2: a slave boson study.

We investigate the electronic and magnetic properties of K(x)Fe(2-y)Se2 materials at different band fillings utilizing the multi-orbital Kotliar-Ruckenstein slave boson mean-field approach. We find that the ground state of KFe2Se2 is a paramagnetic (PM) bad metal with intermediate correlation, in contrast with the previous antiferromagnetic (AFM) results obtained by the local density approximation. Our PM metallic ground state suggests that KFe2Se2 is the parent phase of superconducting K(x)Fe(2-y)Se2, supporting a recent scanning tunneling spectroscopy experiment. For pure Fe2+-based systems, the ground state is a striped AFM (SAFM) metal with a spin density wave gap partially opened near the Fermi level. In comparison, for Fe3+-based compounds, besides SAFM, a Néel AFM metal without orbital ordering is observed, and an orbital selective Mott phase (OSMP) accompanied by an intermediate-spin to high-spin transition is also found, giving a possible scenario of an OSMP in K(x)Fe(2-y)Se2. These results demonstrate that the band filling and correlation control the Fermi surface topology, electronic state and magnetism in K(x)Fe(2-y)Se2.

A local risk prediction model for prolonged ventilation after adult heart valve surgery in a Chinese single center.

BACKGROUND AND AIM OF THE STUDY: The aim of this study was to develop a logistic risk prediction model for prolonged ventilation after adult heart valve surgery. MATERIALS AND METHODS: This is a retrospective observational study of collected data on 3965 consecutive patients older than 18 years, who had undergone heart valve surgery between January 2000 and December 2010. Data were randomly split into a development dataset (n = 2400) and a validation dataset (n = 1565). A multivariate logistic regression analysis was undertaken using the development dataset to identify independent risk factors for prolonged ventilation (defined as ventilation greater than 72 h). Performance of the model was then assessed by observed and expected rates of prolonged ventilation on the development and validation dataset. Model calibration and discriminatory ability were analyzed by the Hosmer-Lemeshow goodness-of-fit statistic and the area under the receiver operating characteristic (ROC) curve, respectively. RESULTS: There were 303 patients that required prolonged ventilation (7.6%). Preoperative independent predictors of prolonged ventilation are shown with odds ratio and P value as follows: (1) age, 1.9, P < .0001; (2) hypercholesterolemia, 5.3, P = .001; (3) renal failure, 18.2, P = .004; (4) previous cardiac surgery, 2.4, P = .0002; (5) left bundle branch block, 4.2, P = .011; (6) ejection fraction, 1.4, P = .003; (7) left ventricle weight, 1.5, P = .007; (8) New York Heart Association class III-IV, 1.8, P = .021; (9) critical preoperative state, 4.5, P < .0001; (10) tricuspid insufficiency, 1.2, P = .031; (11) concurrent CABG, 2.2, P = .019; and (12) concurrent other cardiac surgery, 2.1, P = .001. The Hosmer-Lemeshow goodness-of-fit statistic was not statistically significant in both development and validation dataset (P = .202 vs P = .291). The ROC curve for the prediction of prolonged ventilation in development and validation dataset was .789 and .710, respectively. CONCLUSIONS: We developed and validated a local risk prediction model for prolonged ventilation after adult heart valve surgery. This model can be used to calculate patient-specific risk by the logistic equation with an equivalent predicted risk at our center in future clinical practice.

Risk factors for postoperative recurrence of cardiac myxoma and the clinical managements: a report of 5 cases in one center and review of literature.

BACKGROUND: Recurrence or metastasis of myxomas is not rare and can lead to malignancy. We aimed to analyze the risk factors for postoperative cardiac myxoma recurrence and to summarize its clinical characteristics, treatments and classification. METHODS: The clinical data of 5 patients with recurrent cardiac myxoma were retrospectively analyzed and our clinical experience was summarized. Moreover, the relevant literatures were reviewed. RESULTS: All the five cases of primary myxomas were derived from atypical positions. One patient had early distant metastasis, one had family history, and two suffered malignant recurrence. The recurrence interval was (2.30 ± 2.16) years and the recurrent tumors were all found in different chambers from those of the corresponding primary tumors. Re-operation was performed after recurrence. One patient died of heart failure after malignant recurrence, and the other 4 cases had satisfactory therapeutic outcomes after re-operations. Our experience advocated a clinical classification of "typical" and "atypical" cardiac myxoma, the typical myxomas referred to the tumors locating at the left atria, with single pedicle, rooted at or around the fossa ovalis, involving no genetic causes, and the atypical myxomas included the familial tumors, tumors stemming from multiple chambers, rooted in abnormal positions of the left atrium, with evident genetic mutation, or with malignant tendency. CONCLUSIONS: Postoperative follow-up is of vital importance for patients with myxomas characterized by multi-chamber distribution, early distant metastasis, atypical origin, and family history. Once recurs, re-operation is necessary and should be performed immediately.

Influence of electronic correlations on orbital polarizations in the parent and doped iron pnictides.

Orbital polarization and electronic correlation are two essential aspects in understanding the normal-state and superconducting properties of multi-orbital FeAs-based superconductors. In this paper, we present a systematic study on the orbital polarization of iron pnictides from weak to strong Coulomb correlations within the Kotliar-Ruckenstein slave boson approach. The magnetic phase diagram of the two-orbital model for LaFeAsO clearly shows that a striped antiferromagnetic metallic phase with orbital polarization exists over a wide doping range, in addition to the Slater-type insulator, Mott insulator and paramagnetic phases. A reversal of the orbital polarization occurs in the intermediate correlation regime in the absence of the crystal field splitting; however, a small crystal field splitting considerably enhances the orbital polarization, and stabilizes the xz-type orbital order. We argue that the ferro-orbital polarization is characteristic of a density wave, and leads to a pseudogap-like behavior in the density of states.

Relation between zinc, copper, and magnesium concentrations following cardiopulmonary bypass and postoperative atrial fibrillation in patients undergoing coronary artery bypass grafting.

Atrial fibrillation is the most frequently encountered arrhythmia following cardiac surgery. Since the essential trace elements zinc, copper, and magnesium are suspected to have an effect on postoperative atrial fibrillation, the concentrations of these elements were determined by flame atomic absorption spectrophotometry in the plasma of 60 patients undergoing elective coronary artery bypass grafting. Blood samples were collected every 30 min during cardiopulmonary bypass and postoperatively. Plasma concentrations of copper, zinc, and magnesium were measured with flame atomic absorption spectrophotometry. All patients were monitored by continuous electrocardiography until they became outpatients or immediately after atrial fibrillation had taken place. Atrial fibrillation occurred in 13 of the 60 patients, corresponding to 21.7%. The zinc and copper concentrations at postoperative days 1 and 3 were significantly different (P < 0.05) between patients with and without atrial fibrillation. The concentrations of zinc following cardiopulmonary bypass recovered more slowly in patients with postoperative atrial fibrillation than in patients without it. Whether or not supplemental zinc could lower the incidence of postoperative atrial fibrillation should be evaluated in future prospective randomized clinical trials.

[Methods and results of surgical treatment for aortic root pathology due to Stanford A aortic dissection].

OBJECTIVE: To investigate the effectiveness of surgical approaches, outcomes and prognosis of aortic root pathology due to Stanford A aortic dissection. METHODS: Retrospective analysis the clinical data of 161 patients (122 male and 39 female, mean age of (44 ± 21) years) underwent surgical treatment for Stanford A aortic dissection between January 2001 and June 2011. There were 146 patients of acute aortic dissection and 15 patients of chronic aortic dissection. All the patients had aortic root pathologies that included commissural prolapsed in 140 cases, more than moderate aortic insufficiency in 75 cases, aortic sinus intima rupture in 15 cases, right and/or left coronary artery tearing in 8 cases, right and/or left coronary artery dissection in 16 cases, aortic root aneurysm in 31 cases. RESULTS: Aortic root replacement (Bentall procedures) were used in 72 cases, aortic root remodeling (including aortic valve replacement) in 80 cases, aortic root reimplantation (David procedure) in 9 cases. The cardiopulmonary bypass time was shorter in aortic root remodeling group ((193 ± 42) minutes) than the other two groups ((210 ± 61) minutes, (197 ± 34) minutes, F = 3.22, P = 0.04). The in-hospital mortality was 8.1% (13 cases), 5 cases (6.9%) in aortic root replacement group, 7 cases (8.8%) in aortic root remodeling group, 1 case in aortic root reimplantation. The cause of death included respiratory failure (4 cases), permanent neurological deficits (3 cases), multiple organ failure (4 cases), acute renal failure (2 cases). The survivors were followed up for 6 months to 6 years. There was no patient required reoperation for aortic root pathologies. There was no statistically significant difference between aortic root remodeling group and reimplantation group (P > 0.05). CONCLUSIONS: The surgical treatment for aortic root pathology due to Stanford A aortic dissection is challenging. Appropriate procedures according to the specialty of aortic root pathology can be performed with favorable functional results.

[Perioperative monitoring and control of hyperglycemia during deep hypothermic circulatory arrest].

OBJECTIVE: To observe the trend of change in perioperative blood glucose level in patients undergoing deep hypothermic circulatory arrest (DHCA), in order to evaluate the influencing factors of inciting hyperglycemia and the clinical effects of insulin control. METHODS: In the Department of Cardiothoracic Surgery of Changhai Hospital, 176 patients underwent aortic operation under DHCA from January 2000 to January 2010. Blood glucose, arterial blood gas and lactate levels were determined at four time points, including pre-cardiopulmonary bypass (CPB), pre-DHCA, post-DHCA, and at admission to intensive care unit (ICU). Hyperglycemia after surgery was controlled at the level of 6-8 mmol/L by intermittent subcutaneous injection or intravenous micropump injection of insulin. At the same time, the cumulative amount of insulin within 24 hours after surgery was recorded. RESULTS: The blood glucose (mmol/L) level at pre-DHCA time point was significantly higher than that of pre-CPB (9.62 ± 1.79 vs. 5.04 ± 1.401,P<0.05), and the blood glucose level was further elevated at the time point of post-DHCA (14.91 ± 2.36,P<0.01) and in-ICU (15.32 ± 2.47) compared with that of pre-CPB (P<0.01). The level of blood glucose elevation was positively correlated with blood lactate level. One hundred and thirty-four patients (76.1%) insulin was given with intravenous micropump due to poor effect of intermittent subcutaneous injection of insulin in controlling blood glucose. Among whom 30 patients (17.0%) developed the phenomenon of insulin resistance. Perioperative hyperglycemia during DHCA was associated with old age (≥ 50 years old), primary hypertension, serious aortic valve disease, diabetes or coronary heart disease, emergency operation, CPB time ≥ 3 hours and DHCA time ≥ 45 minutes. The cumulative amount of insulin within 24 hours after surgery was increased significantly. The results of blood glucose (mmol/L) in-ICU were as follows : age ≥ 50 years old or < 50 years old (18.66 ± 2.52 vs. 12.90 ± 2.27); hypertension with and without (18.98 ± 2.55 vs. 12.31 ± 2.34); serious aortic valve disease with and without (19.59 ± 2.95 vs. 12.13 ± 2.23); diabetes with and without (20.62 ± 1.76 vs. 11.75 ± 1.11); coronary heart disease with and without (19.77 ± 2.98 vs. 12.01 ± 2.02); emergency operation with and without (19.78 ± 1.97 vs. 12.23 ± 1.38); CPB time ≥ 3 hours or < 3 hours (19.86 ± 1.89 vs. 11.70 ± 1.15); DHCA time ≥ 45 minutes or < 45 minutes (19.92 ± 1.88 vs. 11.64 ± 1.12), and all of them should statistical difference (all P < 0.05). The cumulative amount of insulin (U) within 24 hours after surgery was as follows: age ≥ 50 years old or < 50 years old (169.5 ± 56.6 vs. 110.2 ± 38.5); hypertension with and without (171.6 ± 64.0 vs. 104.8 ± 34.3); aortic valve disease with and without (171.4 ± 36.8 vs. 109.4 ± 27.6); diabetes with and without (202.5 ± 46.7 vs. 100.4 ± 31.5); coronary heart disease with and without (178.5 ± 38.6 vs. 104.6 ± 26.4 ); emergency operation with and without (178.3 ± 35.7 vs. 102.7 ± 26.8); CPB time ≥ 3 hours or < 3 hours (168.6 ± 37.2 vs. 107.3 ± 27.5); DHCA time ≥ 45 minutes or < 45 minutes (172.5 ± 36.1 vs. 105.4 ± 28.7), and all of them showed significant statistical difference (all P < 0.05). and all of them showed significant statistical difference (all P < 0.05). CONCLUSION: DHCA may cause significant increase in perioperative blood glucose and lactate, and even may lead to insulin resistance. Patients often require continuous intravenous administration of large doses of insulin. Perioperative hyperglycemia during DHCA is related to many factors, which should be considered in control of blood glucose.

[Reoperative valve replacement in patients undergoing cardiac reoperation: a report of 104 cases].

OBJECTIVE: To review the experience of reoperative valve replacement for 104 patients. METHODS: From January 2002 to December 2009, 104 patients underwent heart valve replacement in reoperations, accounting for 2.92% of the total patient population (3557 cases) who had valve replacement during this period. In this group, 53 male and 51 female patients were included with a median age of 46 years (ranged from 13 to 72 years). The reasons of reoperation included 28 cases suffered from another valve lesion after valve replacement, 10 cases suffered from valve lesion after mitral valvuloplasty, 19 cases suffered from perivalvular leakage after valve replacement, 18 cases suffered from valve lesion after previous correction of congenital heart defect, 7 cases suffered from bioprosthetic valve decline, 10 cases suffered from prosthetic valve endocarditis, 9 cases suffered from dysfunction of machine valve, and 3 cases suffered from other causes. The re-operations were mitral and aortic valve replacement in 2 cases, mitral valve replacement in 59 cases, aortic valve replacement in 24 cases, tricuspid valve replacement in 16 cases, and Bentall's operation in 3 cases. The interval from first operation to next operation was 1 month-19 years. RESULTS: There were 8 early deaths from heart failure, renal failure and multiple organ failure (early mortality 7.69%). Major complications were intraoperative hemorrhage in 2 cases, re-exploration for mediastinal bleeding in 2 cases and sternotomy surgical site infection in 1 case. Complete follow-up (3 months-7 years and 2 months) was available for all patients. Two patients died, one patient died of intracranial hemorrhage, and another cause was unknown. CONCLUSION: Satisfactory short-term and long-term results can be obtained in reoperative valve replacement with appropriate timing of operation control, satisfactory myocardial protection, accurate surgical procedure and suitable perioperative treatment.

Association of single-nucleotide polymorphisms in toll-like receptor 5 gene with rheumatic heart disease in Chinese Han population.

This case-control study was carried out to investigate the association of single-nucleotide polymorphisms (SNPs) in toll-like receptor 5 (TLR5) gene and rheumatic heart disease (RHD) among the Chinese Han population. A group of 239 patients with RHD and 478 healthy controls were studied. Three tag single-nucleotide polymorphisms (tSNPs) in TLR5 gene (rs1640827, rs2353476, and rs5744140) were identified with microarray hybridization analysis. Significant differences were observed in the distribution of alleles and genotypes between the patients with RHD and the controls for either rs1640827 or rs2353476. Patients with RHD also have higher frequencies of CGC and CAC haplotypes. These findings indicate that the genetic variants of TLR5 gene might be associated with RHD in Chinese Han population.

[Surgical treatment of congenital quadricuspid aortic valve].

OBJECTIVE: To improve the understanding of congenital quadricuspid aortic valve (QAV), explore its echocardiographic diagnostic value and summarize the methods and outcomes of surgical treatments. METHODS: The clinical data of 11 QAV patients from January 2000 to December 2008 were retrospectively analyzed. There were 9 males and 2 females with a mean operative age of (32±16) years (range: 4-55). RESULTS: In 766 patients undergoing aortic valve surgery, 11 were of congenital quadricuspid aortic valve (1.4%); cardiac pathology: infective endocarditis (n=1), left superior vena cava (n=1), aortic aneurysm (n=1), mitral prolapse (n=1) and tricuspid insufficiency (n=1). The patients of congenital QAV deformity was diagnosed by echocardiography (n=7), misdiagnosed as single valve (n=1), misdiagnosed as bicuspid valve (n=1) and misdiagnosed as rheumatic heart disease (n=2). Type B (n=7), Type A (n=2), Type F (n=1) and Type G (n=1). Eleven patients underwent the procedure of aortic valve replacement. And the concomitant procedures were aortic root broadening (n=1), ascending aortoplasty (n=1), mitral valvuloplasty (n=1) and tricuspid valvuloplasty (n=1). CONCLUSION: Quadricuspid aortic valve is rare in clinical practice. And echocardiography plays an important diagnostic role. Surgical replacement of aortic valve is the first-line therapy for these patients.