Two-way choice is the main way for the seven-year-program clinical medical students and postgraduate supervisors.This article analyzes the influence factors and shortages of two-way choice for postgraduate supervisors and seven-year-program clinical medical students.This investigation discovers that the supervisor's abilities of research,teaching and clinical and their personal magnetism are important and key factors.The students' gender,character,hobbies and interests and the familiarity to profession are the secondary factors.The other factors that include employment status,the level of income and the advice of parents and friends also have influence on two-way choice for postgraduate supervisors and seven-year-program clinical medical students.In order to further improve the tow-way choice,the author gives some suggestions,including introducing profession and the scientific researches of supervisors in advance,encouraging the face-to-face communication between students and supervisors,promoting multiple profession choices and giving some aids to the students for choosing the supervisors.

Pedicle screw fixation is widely used in spine surgery, which allows 3?dimensional fixation with a more rigid construct and permits a shorter fusion length. However, conventional pedicle screw fixation has some drawbacks, including signifi?cant muscle dissection for the exposure of bone marks. Although percutaneous pedicle screw technique can compensate for above defects, it requires an additional approach for decompression and bone graft insertion. Besides, the percutaneous pedicle screw technique depends on intraoperative multiplanar fluoroscopy, which results in high risk of radiation exposure of the surgeons and patients. Screw loosening is a well?known complication, especially in osteoporosis patients. Several methods can enhance screw stability, for example, modifying screw design and augmenting vertebral bodies with reinforcing materials that can improve the structural capacity of the deteriorated tissue, however, they also have some disadvantages. Although we can enhance bone?screw by modifying screw design, it is not useful in severe osteoporosis patients. At the same time, bone cement can increase pedicle screw axial pullout strength and fatigue resistance, however, it is associated with a number of inherent disadvantages such as its high exothermic polymerizing temperature, toxicity of the monomer, and risk of leakage to the spinal canal. Santoni et al. intro?duced cortical bone trajectory (CBT) for lumbar pedicle screw with a new screw design that is shorter and smaller in diameter which has been proposed to maximize the thread contact with this higher density bone surface. In addition, the CBT technique fol?lows a caudocephalad path sagittally and a laterally directed path in the transverse plane, engaging only cortical bone in the pedi?cle without the involvement of the vertebral body trabecular space. Finally, the screw insertion point of this technique locates around lateral pars, enabling less tissue dissection. Therefore, it can be an alternative approach to enhance screw fixation strength, and it may rescue failed pedicle screw and be used in minimally invasive spine surgery.

Objective　This study was To investigate the incidence rate of Cockett syndrome and relationship between Cockett syndrome and varicose veins and deep venous incompetence of the left lower extremities.Methods　73 patients(100 legs) with varicose veins of the lower extremities were investigated by descending deep venography and iliography preoperatively.Results　There were 35(47.9%) cases with abnormalities of the left common iliac vein (ALCIV)in all the cases.There were 31 cases with this conditions in the patients with varicose veins of the left or both lower extremity.While in the patients with varicose veins of the only right lower extremity,there were only 4 cases with ALCIV.In contrast,there was a significant difference between groups(χ2=9.8641,P=0.0017).In the patients with ALCIV,14 cases with Ⅲ or Ⅳ grade of deep venous incomptence were found, and only 6 cases with deep venous incompetence in the patients without ALCIV.There was a significant difference(χ2=5.3688,P=0.0205).Conclusion　Cockett's syndrome frequently occurs in varicose veins of the left lower extremity.There is a relationship between them.Cockett's syndrome might be one of the causes for the deep venous incompetence of the left leg.

Objective To investigate the alkaloidal constituents of Nauclea officinalis, an anti-inflammatory and antibacterial traditional Chinese herb. Methods The alkaloids were isolated and purified by silica gel, Sephadex LH20, and C-18 ODS column chromatography repeatedly, and their structures were identified by spectral analysis. Results Eleven alkaloids were isolated from the stems of N. officinalis and their structures were identified as angustoline (Ⅰ), 19-O-ethylangustoline (Ⅱ), 3-S-3, 4-dihydroangustoline (Ⅲ), 3-R-3, 4-dihydroangustoline (Ⅳ), naucleamide A (Ⅴ), strictosamide (Ⅵ), vincosamide (Ⅶ), 6′-acetyl-strictosamide (Ⅷ), 2′-acetyl-strictosamide (Ⅸ), pumiloside (Ⅹ), 3-epi-pumiloside (Ⅺ). Conclusion Compounds Ⅰ-Ⅺ are isolated from this plant for the first time.

Objective To prove that valve sparing aortic root reconstruction may have an impact on the outcome and longevity of the repair for patients with acute type A aortic dissection.Methods Clinical data of 98 consecutive AAAD patients undergoing the valve sparing aortic root reconstruction were analyzed.The postoperative follow-up and the clinical effect of the procedure were retrospectively analyzed.Results Pre-operative grade of aortic insufficiency was(2.3 ± 0.5), CPB-time was (217.8 ± 43.1)min, aortic cross clamp time was(142.7 ± 37.4)min and stay on ICU (11.1 ± 5.7) days, while hospitalisation was(14.3 ± 3.2) days.8 patients(8.2％) died peri-operatively.None of the early deaths were valve-related.Rethoracotomy rate was 3.1％.All patients followed up(19.3 ± 7.6) (6-68) months.Survival at 1 year was 90.8％.Freedom from valvular reoperation was 97.9％ at 3 years.At last investigation, mean grade of aortic insufficiency for AADA was 0.5 ± 0.3 (0-3).Conclusion Regardless of the underlying indication, the aortic valve preserving reimplantation technique can be performed with favourable functional results.

Cardiac surgery carried out on cardiopulmonary bypass(CPB) in a pregnant woman is associated with poor neonatal outcomes although maternal outcomes are similar to cardiac surgery in non-pregnant women.Most adverse maternal and fetal outcomes from cardiac surgery during pregnancy are attributed to effects of CPB.The CPB is associated with utero-placental hypoperfusion due to a number of factors,which may translate into low fetal cardiac output,hypoxia and even death.Better maternal and fetal outcomes may be achieved by early pre-operative optimization of maternal cardiovascular status,use of perioperative fetal monitoring,optimization of CPB,delivery of a viable fetus before the operation and scheduling cardiac surgery on an elective basis during the second trimester.

Objective:To study the influence of r-tPA and urokinase in curative effect and thrombolysis time on patients with acute and severe pulmonary embolism after interventional thrombectomy .Methods:After reviewing and analyzing the clinical data of 19 acute and severe pulmonary embolism patients , we classified them into two groups in accordance with the application of r-tPA and urokinase to compare the changes of their heart rate , blood pressure , pulmonary arterial pressure , arterial partial pressure of oxygen and hemachrome before and after thrombolysis , as well as the thrombolysis effect time the two groups took.Results: The heart rate, blood pressure, pulmonary arterial pressure , arterial partial pressure of oxygen of the patients in both groups gained remarkable improvement after operation ( P<0 .05 );the pulmonary arterial pressure of the r-tPA patient group dropped but not significantly compared with that before operation ( P>0.05); the pulmonary arterial pressure of the urokinase patient group dropped significantly compared with that study before operation ( P<0.05 ); the hemachrome of both patient groups did not significantly drop after operation ( P>0 .05 );the thrombolysis effect time by adop-ting r-tPA was remarkably shorter than that caused in thrombolysis by adopting urokinase ( P<0 .05 ) . Conclusion: Both r-tPA and urokinase are effective in interventional thrombolysis for acute and severe pulmonary embolism .However , r-tPA could significantly shorten the time caused in thrombolysis without increasing any bleeding risk.

The necessity to apply medical devices properly was introduced, and the present situation of the application of hospital medical devices were discussed from the aspects of overuse, abuse, operation and supervision. Some countermeasures were put forward to solve the problems in the application of hospital medical devices. It's pointed out that the application of hospital medical devices tends to be standardized with the progress of medical reformation, the attention on medical devices management, the supervision and etc.

Cells, Cultured ; DNA Damage ; drug effects ; Dimethylformamide ; administration & dosage ; toxicity ; Dose-Response Relationship, Drug ; Hepatocytes ; drug effects ; pathology ; Humans