1T-CrO2 monolayer: a high-temperature Dirac half-metal for high-speed spintronics.

Two-dimensional (2D) materials with complete spin-polarization, high-speed conduction electrons, large Curie temperatures and robust ferromagnetic ground states are desirable for spintronic applications. Based on first-principles calculations, we demonstrate that the 1T-CrO2 monolayer is an intrinsic 3d ferromagnetic Dirac half metal (DHM) with two symmetry protected Dirac cones near the Fermi level. The Fermi velocities (3.21 × 105 m s-1 and 4.85 × 105 m s-1) of the Dirac cones are in the same order as that of graphene, indicating its excellent transport properties. Its 2.48 eV half-metallic gap is large enough to prevent the spin-flip transition. Moreover, the two Dirac cones are robust against biaxial strain of up to ±4%. The robust ferromagnetism is mainly contributed by the 3d states of Cr and its Curie temperature is up to 507 K. Our results indicate that the ferromagnetic 1T-CrO2 monolayer is a promising candidate for high temperature, high efficiency spintronics applications.

[Long-term outcome comparison of ostial/shaft lesions in unprotected left main coronary artery treated by PCI or CABG].

Objective: To evaluate long-term clinical outcomes of consecutive patients treated with coronary artery bypass grafting (CABG) and percutaneous coronary intervention(PCI) with drug-eluting stents(DES) for ostial/shaft lesions in unprotected left main coronary artery(ULMCA). Method: A total of 259 patients with isolated ostial/midshaft lesions in unprotected left main coronary artery were enrolled consecutively who received DES implantation or underwent CABG between January 2003 and July 2009 in Beijing Anzhen Hospital. The endpoints of the study were death, repeat revascularization, myocardial infarction (MI) and stroke. Time to the primary endpoint was evaluated according to the Kaplan-Meier method, and the log-rank test was applied to compare the incidence of the endpoint. Adjusted risks for adverse outcomes were compared by multivariate Cox proportional hazard regression analyses. Results: A total of 259 patients were included, including 149 in PCI group and 110 in CABG group. And 193(74.5%) cases were males.The age was (61.4±9.8) years old. The median follow-up was 10.1 years (interquartile range 8.3 to 11.2 years) in the overall patients. There were no significant difference for the incidence of death [37.0% vs. 43.1% ，P=0.143] , MI [34.0% vs. 19.4% ，P=0.866], stroke [6.4% vs. 11.7% ， P=0.732], repeart revascularization [33.6% vs. 39.9% ，P=0.522] between PCI group and CABG group before multivariate adjusting，according to the incidence calculated with Kaplan-Meier. After adjusting covariates such as age, left ventricular ejection fraction（LVEF） and serum creatine with multivariate Cox hazard regression model, there was still no significant difference between the two groups. Conclusions: PCI with DES is as effective and safe as CABG in patients with left main ostium/shaft lesion during a median follow-up of 10.1 years.

[Surgical treatment for type Stanford A aortic dissection with Kommerell's diverticulum].

Objective: To examine the outcomes of surgical treatment in patients of type Stanford A aortic dissection with Kommerell's diverticulum. Methods: From January 2009 to August 2017, patients of type Stanford A aortic dissection with Kommerell's diverticulum who underwent the Sun procedure were enrolled. Patient demographic, preoperative, intraoperative, early morbidity and mortality data were collected from medical and electronic patient records. Clinical follow-up data, including late morbidity and mortality, were obtained by telephone interview with the patient. Results: A total of 13 patients (11 males and 2 females; mean age 47 years) were included. The mean maximum diameter of Kommerell's diverticulum was (21.8±7.7) mm. The Kommerell's diverticulum was repaired by direct suture of the orifice in 3 patients, ligation of the aberrant right subclavian artery in 9 patients, and suture and ligation in 1 patient, respectively. No perioperative death occurred. One patient underwent a reexploration for bleeding. There were 2 late deaths: unknown reason in 1 patient and septic shock secondary to renal abscess in 1 patient. Reintervention was performed in one patient for a persistent type Ⅱ endoleak. Conclusions: The Sun procedure with femoral artery cannulation for cardiopulmonary bypass, unilateral carotid artery cannulation for selective cerebral perfusion and ligation of aberrant right subclavian artery on the right side of the trachea is an appropriate therapeutic strategy for patients of type Stanford A aortic dissection with Kommerell's diverticulum.

Identification of Ground Intrusion inUnderground StructuresBased on Distributed Structural Vibration Detected by Ultra-Weak FBG Sensing Technology.

It is challenging for engineers to timely identify illegal ground intrusions in underground systems such as subways. In order toprevent the catastrophic collapse of subway tunnels from intrusion events, this paper investigated the capability of detecting the ground intrusion of underground structures based on dynamic measurement of distributed fiber optic sensing. For an actual subway tunnel monitored by the ultra-weak fiber optic Bragg grating (FBG)sensing fiber with a spatial resolution of five meters, a simulated experiment of the ground intrusion along the selected path was designed and implemented, in which a hydraulic excavator was chosen to exert intrusion perturbations with different strengths and modes at five selected intrusion sites. For each intrusion place, the distributed vibration responses of sensing fibers mounted on the tunnel wall and the track bed were detected to identify the occurrence and characteristics of the intrusion event simulated by the discrete and continuous pulses of the excavator under two loading postures. By checking the on-site records of critical moments in the intrusion process, the proposed detection approach based on distributed structural vibration responses for the ground intrusion can detect the occurrence of intrusion events, locate the intrusion ground area, and distinguish intrusion strength and typical perturbation modes.

Strong anisotropic nodal lines in the TiBe family.

Using first-principles calculations and k·p model analysis, we find that Dirac nodal lines (DNLs) exist in low energy band structures of real materials of the body-centered cubic TiBe family. The nodal lines are protected by mirror reflection symmetries of the systems. The anisotropic electronic state interaction around the Fermi level produces a strong anisotropic quasi-square shape nodal line in the systems. Moreover, all the systems demonstrate drumhead surface states spanning a large energy window showing their potential in terms of high temperature superconductivity. The slight gap induced by spin-orbit coupling (SOC) indicates that materials of the TiBe family are promising candidates for future experimental studies on nontrivial topological semimetals.

[Clinical and pathological features and mutational types of WT1 mutation-associated nephropathy].

Objective: To explore the clinical and pathological features and mutational types and their relations with WT1 mutation-associated nephropathy (WT1MAN). Methods: The clinical and pathological data and the results of WT1 mutation analysis of the cases from Nanfang Hospital of Southern Medical University, Sun Yat-sen Memorial Hospital and The First Affiliated Hospital of Sun Yat-sen University whom we recruited recently and reported during the last ten years were analyzed. Results: Totally, 20 cases (6 males and 14 females), included 5 newly diagnosed cases, were recruited. (1) Ten children were diagnosed with Denys-Drash syndrome (DDS): The median onset age of proteinuria was 1 year and 7 months. Diffuse mesangial sclerosis (DMS) were revealed in 3 cases, minimal lesions (MCD) in 4 cases, and focal segmental glomerulosclerosis (FSGS) in 1 case; renal pathology was not available in the other 2 cases. Glomerular basement membrane (GBM) thickening was observed in 2 cases. Calcineurin inhibitors (CNIs) were administered in 5 cases, complete remission of proteinuria was observed in 3 cases, partial remission in the other 2 cases. Genetic analysis revealed that six cases had WT1 missense mutation, 3 had nonsense mutation, and 1 had frameshift mutation. (2) Two cases were diagnosed with Frasier syndrome (FS): proteinuria was observed at 1 year and 1 month of age and 1 year and 9 months of age, respectively. FSGS with GBM layering were observed in both cases. They progressed to ESRD at 1 year and 6 months of age and 6 years and 6 months of age, respectively. CNI was tried in 1 case with partial proteinuria remission. Both patients were detected to have WT1 splice mutation. (3) Isolated nephropathy (IN) was observed in 8 cases: three had splice mutation, 5 had missense mutation. Of the 3 patients with splice mutation, one was found to have nephropathy and renal failure at the age of 5 months. The other two cases (1 was FSGS and another MCD), both had GBM layering. CNIs were tried on both of them, one got partial remission with normal renal function at the age of fourteen years, the other one had no response and entered ESRD at the age of 6 years and 9 months. Of the 5 cases with missense mutation, 3 had DMS, 2 of them entered ESRD within 6 months of age, another case had DMS entered ESRD at 9 years of age. One case with FSGS, was treated with CNIs and got complete remission. Conclusions: Slow progression (7/10) nephropathy was observed in DDS patients. Missense mutation (11/20) was the most common type of WT1 variants, followed by splice mutation (5/20) in this group of patients. Early onset nephropathy (4/5), rapid progression (4/5) and GBM layering (4/4) wereobserved in patients with splice mutation. CNI was effective in reducing or even eliminating proteinuria in WT1 MAN patients (8/9).

Laminin associated with BMP7 as potential secondary astrocytic glioma fiber differentiation targets.

OBJECTIVE: To investigate the activation of the BMP7 and laminin pathway is associated with glioma cell proliferation and differentiation. PATIENTS AND METHODS: We enrolled 65 patients with primary operable glioma. Laminin and BMP7 protein expression and its subcellular localization were studied by immunofluorescence. RESULTS: We detected a higher level of BMP7 expression in glioma tissue in patients with a lower grade of glioma who had a lower eosinophil count. Compared to patients with a higher grade of glioma, we observed a lower level of laminin expression in patients with a lower grade of glioma. CONCLUSIONS: Our data indicated a potential link between eosinophil counts and the expression levels of laminin and BMP7 in glioma differentiation.

[Reoperation for residual aneurysm of coronary anastomosis after Bentall procedure].

Objective: To introduce a new operative method for residual aneurysm of coronary anastomosis after Bentall procedure. Methods: Between March 2011 and December 2012, six patients in Beijing Anzhen Hospital with residual aneurysm of coronary anastomosis (CT showed goldfish eye sign at the openings of coronary) after Bentall procedure underwent the operation of concentric circular patch procedure under cardiopulmonary bypass. Femoral artery, right atrium and upper right pulmonary artery cannulation were used for cardiopulmonary bypass, and the artificial vessel was transected after cardiac arrest. A concentric circular patch was pruned, whose outside diameter was slightly larger than the aneurysm and the inside diameter was equal to the openings of coronary. The outer edge of the patch was anastomosed to the outer edge of the aneurysm (opening of artificial vessel in primary surgery) with 4-0 prolene. The inner edge of the patch was anastomosed to the openings of coronary with 5-0 prolene. Results: All patients had clinical recovery. Postoperative CT demonstrated the disappearance of residual aneurysm during follow-up (the goldfish eye sign disappeared). Conclusion: The concentric circular patch procedure is a feasible treatment for residual aneurysm of coronary anastomosis.

[Experience of Sun's procedure for chronic type B dissection with aortic arch involvement].

Objective: To study the surgical treatment of chronic type B dissection with aortic arch involvement using Sun's procedure. Methods: Between February 2009 and December 2015, 29 patients [20 males, 9 females, with a mean age of (41±12) years, range 24-64 years] with type B dissection with aortic arch involvement underwent Sun's procedure. Sixteen patient had a history of hypertension. Marfan syndrome was observed in 9 cases, coronary artery disease in 3 cases, mitral regurgitation in 3 patients, cerebrovascular disease in one patient. Twenty-two patients suffered proximal aortic arch disease, 4 cases experienced history of aortic root procedure and 2 subjects had history of pregnancy. Four patients had aortic arch malformation. Results: One case suffered from massive cerebral infarction after surgery and died in another hospital. Concomitant procedures included mitral valve replacement in 3 cases, coronary artery bypass grafting in 3 patients, reconstruction of the right aberrant subclavian artery in one patient. Ventilator support exceeding 24 hours obseved in 2 patients. One of them recieved continuous renal replacement therapy and recovered before discharge. Spinal cord injury was obseved in one case, brain infarction in one patient and pericardial drainage in one case. Two patients required tracheotomy. During 12-94 (43±23) months' follow-up, thoracoabdominal aortic replacment was performed in 4 patients, thoracic endovascular aortic repair (TEVAR) in 2 subjects and repair of perivalvular leakage in one patient. Conclusions: Sun's procedure obtained satisfactory results in patients with chronic type B dissection with aortic arch involvement. Concomitant repair of proximal aortic arch lesions and distal type B dissection can be adopted using Sun's procedure.

[Surgical treatment of aortic dissection with lower extremity ischemia].

Objective: To explore the clinical outcome of the surgical treatment for aortic dissection with lower extremity ischemia. Methods: Between March 2009 and April 2013, 14 patients with type A aortic dissection and lower extremity ischemia underwent Sun's procedure in Beijing Anzhen Hospital. Ascending aorta-iliac artery bypass, ascending aorta-femoral artery bypass, femoral-femoral artery bypass and axillary -femoral artery bypass were performed on some severe patients at the same time. Results: Two death occurred, and the others were improved or recovered from symptoms. Follow-up was complete with an average time of 24 months and no aortic relevant complications occurred. Conclusion: As for patients with type A aortic dissection and lower extremity ischemia, simultaneous radical femoral artery bypass procedure is effective in improving their survival rate and quality of life.

[Progress and challenge of Stanford type A aortic dissection in China].

In recent 20 years, the rapid development of acute Stanford type A aortic dissection in China has been mainly due to three aspects: (1) the refined classification of aortic dissection based on Stanford classification, (2) right axillary artery canal and selective cerebral perfusion technology become basic cardiopulmonary bypass strategy for Stanford type A aortic dissection, and (3) total aortic arch replacement and descending aortic stent graft surgery (Sun's surgery) become the standard treatment of Stanford type A aortic dissection. However, there are still many problems in the diagnosis and treatment of aortic dissection in China, such as: (1) unstandardized, lack of comprehensive guidelines of aortic dissection, (2) immature, perioperative organ protection and intraoperative blood protection technology remains a big flaw, and (3) it takes a long time to get patient prepared for surgery. In conclusion, as to the issue of the management of acute Stanford type A aortic dissection, there will be a long way for Chinese doctors to go. Peers should pay more attention to this problem and take more efforts, so that the outcome of acute Stanford type A aortic dissection surgical patients can be improved.

[Progress of problems related to the reconstruction of aortic arch in acute type A aortic dissection].

Aortic arch reconstruction is one of the most challenging operations in aortic surgery. Anatomical abnormalities of the aortic arch, including bovine aortic arch, aberrant right subclavian artery, and single vertebral artery have direct impact on the choice of surgical procedures and methods of brain protection.The risk of aortic arch reconstruction and the difficulty of operation, it is possible to avoid the injury of patients by strictly grasping the indication of operation. Intraoperative arterial cannulation and brain protection strategies are directly related to the success of the operation. This article makes a brief review of the above problems in the reconstruction of the aortic arch, hoping to be helpful to the cardiovascular surgeon.

[Focal segmental glomerulosclerosis after renal transplantation in a child with ANCA-associated glomerulonephritis: case report and literature review].

Objective: To study the clinical features and treatment of focal segmental glomerulosclerosis (FSGS) after renal transplantation in a child with ANCA-associated glomerulonephritis. Method: The clinical and pathological data of the patient treated in the Department of Pediatrics as well as in the Department of Organ Transplantation in November 2015 in the First Affiliated Hospital of Sun Yat-sen University, who was diagnosed with de novo FSGS after renal transplantation with a primary disease ANCA-associated glomerulonephritis, was analyzed retrospectively. Reports on "ANCA-associated glomerulonephritis" "(renal OR kidney) transplantation" "focal segmental glomerular sclerosis" were searched and reviewed. Result: A ten years old female was definitely diagnosed with ANCA-associated glomerulonephritis on the 81st day after the onset of primary ANCA associated glomerulonephritis. Because of progressive decline of renal function, a hemodialysis period for 7 months was administered following the pulsed methylprednisolone as well as cyclophosphamide treatment. The renal transplantation was then carried out 18 months later, the renal function recovered 7 days later while proteinuria reappeared 28 days after renal transplantation. Based on the anti-rejection treatment, 3 times pulsed methylprednisolone administration did not make difference on reducing the proteinuria and then a renal biopsy was conducted and the transplanted kidney proved to be a newly developed FSGS. Consequently, plasma exchange therapy was administrated. When the plasma exchange course finished, the proteinuria decreased significantly (from 3.270 g/24 h to 0.370 g/24 h). No reports were retrieved either in Chinese databases or at PubMed as well as Medline databases. Conclusion: FSGS appears in transplanted kidney in patient with a primary renal disease as ANCA associated glomerulonephritis with early proteinuria after transplantation as well as negative P-ANCA and MPO. Pathology of renal biopsy revealed FSGS while the pathology of other recipient was not FSGS. The patient had no response to pulsed methylprednisolone therapy. Instead, plasma exchange therapy was an alternative also effective treatment for de novo FSGS in transplanted kidney.

Analysis of risk factors of type a aortic dissection (TAAD) operation of frozen elephant trunk and total arch replacement.

OBJECTIVE: To investigate the incidence and risk factors of acute renal failure (ARF) after operation of frozen elephant trunk and total arch replacement for acute thoracic aortic aneurysm and dissection (TAAD) with mild hypothermic circulatory arrest (MHCA), and to analyze the long-term survival rate of the patients with ARF. PATIENTS AND METHODS: From February 2009 to March 2015, patients with acute TAAD accepted operation of frozen elephant trunk and total arch replacement were enrolled. Those patients who were treated with renal replacement treatment (RRT) before the operation were excluded. The age, gender, cardiovascular disease history, preoperative serum creatinine and extracorporeal circulation duration in operation were recorded. On the basis of requiring RRT after TAAD operation, the patients were divided into ARF group and non-ARF group. The risk factors of ARF after TAAD operation were assessed by univariate and multivariate analysis. After completion of clinical follow-up, Kaplan-Meier curve was drawn to analyze five-year survival. RESULTS: A total of 524 patients were included in the study. 51 cases of them got postoperative ARF. The incidence was 9.7%. The mortality rate of ARF group in the hospital was significantly higher than non-ARF group (25.5% vs. 3.6%; p<0.001). Univariate analysis showed that there was statistically significant difference in the age, gender, hypertension history, preoperative serum creatinine ≥200 µmol/L, extracorporeal circulation duration ≥260 min and combined with coronary artery bypass surgery simultaneously (p<0.05). Multiple logistic regression analysis showed that there were three independent risk factors of ARF after the operation, including hypertension (p=0.031, OR=2.377), preoperative serum creatinine ≥200 µmol/L (p=0.005, OR=4.451) and extracorporeal circulation duration ≥260 min (p=0.002, OR=3.295). The total five-year survival rate of ARF group after the operation was 56%. There was no statistically significant difference in the five-year survival rate between preoperative serum creatinine ≥200 µmol/L group and <200 µmol/L group (p>0.05). CONCLUSIONS: The incidence of ARF after the operation was 9.7%. Preoperative serum creatinine ≥200 µmol/L, hypertension history and extracorporeal circulation duration ≥260 min were independent risk factors of ARF after the operation. The five-year survival rate of ARF after the operation was 56%. The preoperative serum creatinine level had no influence on the postoperative long-term survival.

[Clinical features and gene mutation analysis of 13 Chinese juvenile patients with nephronophthisis].

Objective: To explore the clinical features and pathogenic gene mutation of juvenile nephronophthisis (NPHP) in Chinese patients. Method: Clinical data and blood samples of 27 juvenile NPHP patients from 25 families who were initially clinically diagnosed in six hospitals in Guangdong province were collected. NPHP1 homozygous deletions were detected in all patients. Sequencing of NPHP1 gene was performed when homozygous deletions were not found in patients without eye involvement. In patients with eye involvement, NPHP5 sequencing was carried out initially and subsequently NPHP10 gene and NPHP1 when there were no NPHP5 gene mutation found. Result: Diagnosis was confirmed in 13 patients by renal pathology and (or) gene sequencing, including four boys and nine girls with a median onset age of 8.5(0.1-12.8) years. Seven of the 13 patients had a normal routine urine test and six patients had mild to moderate proteinuria. None had persistent hematuria. The estimated glomerular filtration rate of the 13 patients was (12.7±10.7) ml/(min·1.73 m2) at the time of diagnosis. Renal cysts were found in only five patients by iconography. Decreased renal size was observed in nine cases and normal renal size in four patients. Renal pathology was available in five patients, renal cysts formation at the cortical-medullar area, thickening and laying tubular basement membrane, were observed. Two of the thirteen children had eye involvement, one had liver impairment and one had growth retardation. NPHP1 gene defects were detected in seven patients with a mutation rate of 25.9%, and large homozygous deletions were observed in three patients. Four patients had single point mutations, i. e. compound heterozygous mutations (c.13 C>T and c. 1520+ 5 G>A) in one patient; homozygous mutation in three patients, two patients were siblings from the same pedigree harbored c. 1756 C>T and the other one harbored c. 1298delA. NPHP5 gene homozygous mutation was found in one pedigree. The fourteen children without renal pathology and whose genetic tests were negative shared similar clinical features with the thirteen patients whose diagnosis were confirmed by gene mutation and (or) renal pathology. Conclusion: The onset of juvenile NPHP is insidious. Urine and renal iconography changes are mild or negative. The ratio of NPHP1 mutant patient is similar with previous reports, but the proportion of NPHP1 gene homozygous deletions is much lower and all of the NPHP1 gene single point mutations detected in this research were novel, which indicates a genetic discrepancy existed between Chinese NPHP patients and the western ones.

Two Dimensional Antiferromagnetic Chern Insulator: NiRuCl6.

Density functional theory (DFT) and Berry curvature calculations show that quantum anomalous Hall effect (QAHE) can be realized in two-dimensional(2D) antiferromagnetic (AFM) NiRuCl6. The results indicate that NiRuCl6 behaves as an AFM Chern insulator and its spin-polarized electronic structure and strong spin-orbit coupling (SOC) are responsible for the QAHE. By tuning SOC, we found that the topological property of NiRuCl6 arises from its energy band inversion. Considering the compatibility between the AFM and insulators, AFM Chern insulator provides a new way to archive high temperature QAHE in experiments due to its different magnetic coupling mechanism from that of ferromagnetic (FM) Chern insulator.

[Efficacy of endovascular repair in patients with abdominal aortic aneurysm complicating acute aortic syndrome].

OBJECTIVE: To evaluate the efficacy of simultaneous thoracic endovascular aortic repair (TEVAR) and endovascular aneurysm repair (EVAR) on abdominal aortic aneurysm (AAA) patients complicating acute aortic syndrome (AAS). METHODS: Data of 17 patients (16 men, mean age (65.2±6.9) years old) , who underwent simultaneous TEVAR and EVAR between September 2010 and June 2015 in Beijing Anzhen Hospital, were retrospectively reviewed.All patients were diagnosed with concomitant AAA and AAS by preoperative CTA.All abdominal aortic lesions were AAA and all thoracic aortic lesions were AAS.Under local anesthesia, simultaneous TEVAR and EVAR were performed and emergent simultaneous endovascular repair was performed in 2 patients.Follow up was made at 1 month, 3 months, 6 months, and yearly after the procedure.Procedure success rate, procedure related complications were evaluated. RESULTS: Procedure was successful in all patients.The length of thoracic coverage was (21.0±4.6) cm.The operation time was 150(120, 170) min, and the hospitalization time was 7 (6, 12) d. After a mean of 27.0(5.5, 44.5) months follow up, there were no acute cardiopulmonary complications and contrast induced nephropathy.One patient developed spinal cord ischemia and resolved after treatment.One patient was died for aneurysm rupture at 6 months post operation.One patient developed type Ⅰb endoleak for expansion of right iliac artery at 9 months post operation and was successfully sealed by iliac stent-graft extension. CONCLUSIONS: Combined TEVAR and EVAR can be performed successfully in patients with AAA complicating AAS.When anatomically feasible, simultaneous TEVAR and EVAR can be considered as a effective and safe therapy alternative to patients with multilevel aortic diseases.

[The relationship between preoperative renal failure and severe postoperative hypoxemia of patients received surgical procedures for Stanford A aortic dissection].

OBJECTIVE: To study the relationship between renal failure and severe postoperative hypoxemia of patients received surgical procedure for Stanford A aortic dissection. METHODS: Clinical data of 411 consecutive patients from January 2014 to April 2015, who received surgical procedure for Stanford A aortic dissection in Department of Cardiovascular Surgery of Beijing Anzhen Hospital, were collected retrospectively. The appearance of severe postoperative hypoxemia was recorded in all the cases. All the data about potential prognostic factors was put into the database and analyzed by univariate and multivariate Logistic regression respectively. RESULTS: Severe postoperative hypoxemia (PO2/FiO2<100 mmHg, 1 mmHg=0.133 kPa) happened on 69 cases within 48 hours after procedures, with the incidence rate of 17.1%. Both univariate and multivariate Logistic regression indicated the influence that preoperative creatinine clearance rate had on severe postoperative hypoxemia showed no statistical significance. However, the influence of preoperative serum creatinine showed statistical significance (OR=1.009, 95%CI: 1.000 to 1.018, P=0.048). CONCLUSIONS: The preoperative creatinine clearance rate of patients has no direct relationship with severe postoperative hypoxemia. But the preoperative serum creatinine could be regarded as an independent predictor of severe postoperative hypoxemia.